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Paganetti H, Simone CB, Bosch WR, Haas-Kogan D, Kirsch DG, Li H, Liang X, Liu W, Mahajan A, Story MD, Taylor PA, Willers H, Xiao Y, Buchsbaum JC. NRG Oncology White Paper on the Relative Biological Effectiveness in Proton Therapy. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)02974-2. [PMID: 39059509 DOI: 10.1016/j.ijrobp.2024.07.2152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 06/17/2024] [Accepted: 07/06/2024] [Indexed: 07/28/2024]
Abstract
This position paper, led by the NRG Oncology Particle Therapy Work Group, focuses on the concept of relative biologic effect (RBE) in clinical proton therapy, with the goal of providing recommendation for the next generation clinical trials with proton therapy on the best practice of investigating and using RBE, which could deviate from the current standard proton RBE value of 1.1 relative to photons. In part one, current clinical utilization and practice are reviewed, giving the context and history of RBE. Evidence for variation in RBE is presented along with the concept of linear energy transfer (LET). The intertwined nature of tumor radiobiology, normal tissue constraints, and treatment planning with LET and RBE considerations is then reviewed. Part two summarizes current and past clinical data and then suggests the next steps to explore and employ tools for improved dynamic models for RBE. In part three, approaches and methods for the next generation of prospective clinical trials are explored, with the goal of optimizing RBE to be both more reflective of clinical reality and also deployable in trials to allow clinical validation and inter-patient comparisons. These concepts provide the foundation for personalized biologic treatments reviewed in part four. Finally, we conclude with a summary including short- and long-term scientific focus points for clinical proton therapy. The practicalities and capacity to use RBE in treatment planning are reviewed and considered with more biological data in hand. The intermediate step of LET optimization is summarized and proposed as a potential bridge to the ultimate goal of case-specific RBE planning that can be achieved as a hypothesis generating tool in near-term proton trials.
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Affiliation(s)
- Harald Paganetti
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA, USA; Department of Radiation Oncology, Harvard Medical School, Boston, MA, USA
| | - Charles B Simone
- New York Proton Center, New York, NY, USA; Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Walter R Bosch
- Department of Radiation Oncology, Washington University, St. Louis, MO, USA
| | - Daphne Haas-Kogan
- Department of Radiation Oncology, Harvard Medical School, Boston, MA, USA; Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women's Hospital, Boston Children's Hospital, Boston, MA, USA
| | - David G Kirsch
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada; Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada
| | - Heng Li
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Xiaoying Liang
- Department of Radiation Oncology, Mayo Clinic Florida, Jacksonville, FL, USA
| | - Wei Liu
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, USA
| | - Anita Mahajan
- Department of Radiation Oncology, Mayo Clinic, Rochester MN, USA
| | - Michael D Story
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | - Henning Willers
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA, USA; Department of Radiation Oncology, Harvard Medical School, Boston, MA, USA
| | - Ying Xiao
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Jeffrey C Buchsbaum
- National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
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Mein S, Wuyckens S, Li X, Both S, Carabe A, Vera MC, Engwall E, Francesco F, Graeff C, Gu W, Hong L, Inaniwa T, Janssens G, de Jong B, Li T, Liang X, Liu G, Lomax A, Mackie T, Mairani A, Mazal A, Nesteruk KP, Paganetti H, Pérez Moreno JM, Schreuder N, Soukup M, Tanaka S, Tessonnier T, Volz L, Zhao L, Ding X. Particle arc therapy: Status and potential. Radiother Oncol 2024; 199:110434. [PMID: 39009306 DOI: 10.1016/j.radonc.2024.110434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 06/23/2024] [Accepted: 07/10/2024] [Indexed: 07/17/2024]
Abstract
There is a rising interest in developing and utilizing arc delivery techniques with charged particle beams, e.g., proton, carbon or other ions, for clinical implementation. In this work, perspectives from the European Society for Radiotherapy and Oncology (ESTRO) 2022 physics workshop on particle arc therapy are reported. This outlook provides an outline and prospective vision for the path forward to clinically deliverable proton, carbon, and other ion arc treatments. Through the collaboration among industry, academic, and clinical research and development, the scientific landscape and outlook for particle arc therapy are presented here to help our community understand the physics, radiobiology, and clinical principles. The work is presented in three main sections: (i) treatment planning, (ii) treatment delivery, and (iii) clinical outlook.
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Affiliation(s)
- Stewart Mein
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA; Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, Germany; Division of Molecular and Translational Radiation Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, Heidelberg, Germany; Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
| | - Sophie Wuyckens
- UCLouvain, Molecular Imaging, Radiotherapy and Oncology (MIRO), Brussels, Belgium
| | - Xiaoqiang Li
- Department of Radiation Oncology, Corewell Health, William Beaumont University Hospital, Proton Therapy Center, Royal Oak, MI, USA
| | - Stefan Both
- Department of Radiation Oncology, University Medical Center Groningen, Groningen, The Netherlands
| | | | - Macarena Chocan Vera
- UCLouvain, Molecular Imaging, Radiotherapy and Oncology (MIRO), Brussels, Belgium
| | | | | | - Christian Graeff
- GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany; Technische Universität Darmstadt, Institut für Physik Kondensierter Materie, Darmstadt, Germany
| | - Wenbo Gu
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Liu Hong
- Ion Beam Applications SA, Louvain-la-Neuve, Belgium
| | - Taku Inaniwa
- Department of Accelerator and Medical Physics, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan; Department of Medical Physics and Engineering, Graduate School of Medicine, Division of Health Sciences, Osaka University, Osaka, Japan
| | | | - Bas de Jong
- Department of Radiation Oncology, University Medical Center Groningen, Groningen, The Netherlands
| | - Taoran Li
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Xiaoying Liang
- Department of Radiation Oncology, Mayo Clinic Jacksonville, Jacksonville, FL, USA
| | - Gang Liu
- Department of Radiation Oncology, Corewell Health, William Beaumont University Hospital, Proton Therapy Center, Royal Oak, MI, USA; Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Antony Lomax
- Centre for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland; ETH, Department of Physics, Zürich, Switzerland
| | - Thomas Mackie
- Department of Human Oncology, University of Wisconsin School of Medicine, Madison, WI, USA
| | - Andrea Mairani
- Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, Germany; National Centre of Oncological Hadrontherapy (CNAO), Medical Physics, Pavia, Italy
| | | | - Konrad P Nesteruk
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, USA; Harvard Medical School, Boston, USA
| | - Harald Paganetti
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, USA; Harvard Medical School, Boston, USA
| | | | | | | | - Sodai Tanaka
- Department of Accelerator and Medical Physics, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan
| | | | - Lennart Volz
- GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany; Technische Universität Darmstadt, Institut für Physik Kondensierter Materie, Darmstadt, Germany
| | - Lewei Zhao
- Department of Radiation Oncology, Stanford University, Stanford, CA, USA
| | - Xuanfeng Ding
- Department of Radiation Oncology, Corewell Health, William Beaumont University Hospital, Proton Therapy Center, Royal Oak, MI, USA.
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Lyngholm E, Stokkevåg CH, Lühr A, Tian L, Meric I, Tjelta J, Henjum H, Handeland AH, Ytre-Hauge KS. An updated variable RBE model for proton therapy. Phys Med Biol 2024; 69:125025. [PMID: 38527373 DOI: 10.1088/1361-6560/ad3796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 03/25/2024] [Indexed: 03/27/2024]
Abstract
Objective.While a constant relative biological effectiveness (RBE) of 1.1 forms the basis for clinical proton therapy, variable RBE models are increasingly being used in plan evaluation. However, there is substantial variation across RBE models, and several newin vitrodatasets have not yet been included in the existing models. In this study, an updatedin vitroproton RBE database was collected and used to examine current RBE model assumptions, and to propose an up-to-date RBE model as a tool for evaluating RBE effects in clinical settings.Approach.A proton database (471 data points) was collected from the literature, almost twice the size of the previously largest model database. Each data point included linear-quadratic model parameters and linear energy transfer (LET). Statistical analyses were performed to test the validity of commonly applied assumptions of phenomenological RBE models, and new model functions were proposed forRBEmaxandRBEmin(RBE at the lower and upper dose limits). Previously published models were refitted to the database and compared to the new model in terms of model performance and RBE estimates.Main results.The statistical analysis indicated that the intercept of theRBEmaxfunction should be a free fitting parameter and RBE estimates were clearly higher for models with free intercept.RBEminincreased with increasing LET, while a dependency ofRBEminon the reference radiation fractionation sensitivity (α/βx) did not significantly improve model performance. Evaluating the models, the new model gave overall lowest RMSE and highest R2 score. RBE estimates in the distal part of a spread-out-Bragg-peak in water (α/βx= 2.1 Gy) were 1.24-1.51 for original models, 1.25-1.49 for refits and 1.42 for the new model.Significance.An updated RBE model based on the currently largest database among published phenomenological models was proposed. Overall, the new model showed better performance compared to refitted published RBE models.
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Affiliation(s)
- Erlend Lyngholm
- Department of Physics and Technology, University of Bergen, Bergen, Norway
| | - Camilla Hanquist Stokkevåg
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| | - Armin Lühr
- Department of Physics, TU Dortmund University, Dortmund, Germany
| | - Liheng Tian
- Department of Physics, TU Dortmund University, Dortmund, Germany
| | - Ilker Meric
- Department of Computer Science, Electrical Engineering and Mathematical Sciences, Western Norway University of Applied Sciences, Bergen, Norway
| | - Johannes Tjelta
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| | - Helge Henjum
- Department of Physics and Technology, University of Bergen, Bergen, Norway
| | - Andreas Havsgård Handeland
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
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Pan VA, Tran LT, Madden T, Clasie B, Kooy H, Rosenfeld AB, Depauw N. LET d Optimization Verification With an SOI Microdosimeter. Int J Radiat Oncol Biol Phys 2024; 119:946-956. [PMID: 38300188 DOI: 10.1016/j.ijrobp.2023.12.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 11/30/2023] [Accepted: 12/23/2023] [Indexed: 02/02/2024]
Abstract
PURPOSE A first of its kind experimental verification of dose-averaged linear energy transfer (LETd) optimized treatment plans for proton therapy has been carried out using a silicon-on-insulator microdosimeter at the Massachusetts General Hospital (MGH), Boston, USA. METHODS AND MATERIALS Three clinical treatment plans of a typical ependymoma structure set were designed using the standard clinical approach, the proposed protocol approach, and a one-field approach. The plans were then reoptimized to reduce the LETd-weighted dose in the brain stem. All six plans were delivered in a solid water phantom and the experimental yD‾ measured. RESULTS After LETd optimization, a reduction in yD‾ was found within the brain stem by an average of 12%, 19%, and 4% for the clinical, protocol, and one-field plans, respectively, while maintaining adequate coverage of the tumor structure. The experimental LETd-weighted doses were in agreement with the treatment planning system calculations and Monte Carlo simulations and reinforced the improvement of the optimization. CONCLUSIONS This work demonstrates the first experimental verification of the clinical implementation of LETd optimization for patient treatment with proton therapy.
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Affiliation(s)
- V A Pan
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, NSW, Australia.
| | - L T Tran
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - T Madden
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - B Clasie
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - H Kooy
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - A B Rosenfeld
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - N Depauw
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
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Rana S, Manthala Padannayil N, Tran L, Rosenfeld AB, Saeed H, Kasper M. Quantifying the Dosimetric Impact of Proton Range Uncertainties on RBE-Weighted Dose Distributions in Intensity-Modulated Proton Therapy for Bilateral Head and Neck Cancer. Curr Oncol 2024; 31:3690-3697. [PMID: 39057144 PMCID: PMC11275331 DOI: 10.3390/curroncol31070272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2024] [Revised: 06/06/2024] [Accepted: 06/08/2024] [Indexed: 07/28/2024] Open
Abstract
BACKGROUND In current clinical practice, intensity-modulated proton therapy (IMPT) head and neck cancer (HNC) plans are generated using a constant relative biological effectiveness (cRBE) of 1.1. The primary goal of this study was to explore the dosimetric impact of proton range uncertainties on RBE-weighted dose (RWD) distributions using a variable RBE (vRBE) model in the context of bilateral HNC IMPT plans. METHODS The current study included the computed tomography (CT) datasets of ten bilateral HNC patients who had undergone photon therapy. Each patient's plan was generated using three IMPT beams to deliver doses to the CTV_High and CTV_Low for doses of 70 Gy(RBE) and 54 Gy(RBE), respectively, in 35 fractions through a simultaneous integrated boost (SIB) technique. Each nominal plan calculated with a cRBE of 1.1 was subjected to the range uncertainties of ±3%. The McNamara vRBE model was used for RWD calculations. For each patient, the differences in dosimetric metrices between the RWD and nominal dose distributions were compared. RESULTS The constrictor muscles, oral cavity, parotids, larynx, thyroid, and esophagus showed average differences in mean dose (Dmean) values up to 6.91 Gy(RBE), indicating the impact of proton range uncertainties on RWD distributions. Similarly, the brachial plexus, brain, brainstem, spinal cord, and mandible showed varying degrees of the average differences in maximum dose (Dmax) values (2.78-10.75 Gy(RBE)). The Dmean and Dmax to the CTV from RWD distributions were within ±2% of the dosimetric results in nominal plans. CONCLUSION The consistent trend of higher mean and maximum doses to the OARs with the McNamara vRBE model compared to cRBE model highlighted the need for consideration of proton range uncertainties while evaluating OAR doses in bilateral HNC IMPT plans.
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Affiliation(s)
- Suresh Rana
- Department of Radiation Oncology, Lynn Cancer Institute, Boca Raton Regional Hospital, Baptist Health South Florida, Boca Raton, FL 33486, USA
- Department of Radiation Oncology, Florida International University, Miami, FL 33199, USA
| | - Noufal Manthala Padannayil
- Department of Radiation Oncology, Lynn Cancer Institute, Boca Raton Regional Hospital, Baptist Health South Florida, Boca Raton, FL 33486, USA
| | - Linh Tran
- Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2522, Australia
| | - Anatoly B. Rosenfeld
- Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2522, Australia
| | - Hina Saeed
- Department of Radiation Oncology, Lynn Cancer Institute, Boca Raton Regional Hospital, Baptist Health South Florida, Boca Raton, FL 33486, USA
- Department of Radiation Oncology, Florida International University, Miami, FL 33199, USA
| | - Michael Kasper
- Department of Radiation Oncology, Lynn Cancer Institute, Boca Raton Regional Hospital, Baptist Health South Florida, Boca Raton, FL 33486, USA
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Domingo Muñoz I, Van Hoey O, Parisi A, Bassler N, Grzanka L, De Saint-Hubert M, Vaniqui A, Olko P, Sądel M, Stolarczyk L, Vestergaard A, Jäkel O, Gardenali Yukihara E, Brage Christensen J. Assessment of fluence- and dose-averaged linear energy transfer with passive luminescence detectors in clinical proton beams. Phys Med Biol 2024; 69:135004. [PMID: 38774985 DOI: 10.1088/1361-6560/ad4e8e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 05/21/2024] [Indexed: 06/22/2024]
Abstract
Objective.This work investigates the use of passive luminescence detectors to determine different types of averaged linear energy transfer (LET-) for the energies relevant to proton therapy. The experimental results are compared to reference values obtained from Monte Carlo simulations.Approach.Optically stimulated luminescence detectors (OSLDs), fluorescent nuclear track detectors (FNTDs), and two different groups of thermoluminescence detectors (TLDs) were irradiated at four different radiation qualities. For each irradiation, the fluence- (LET-f) and dose-averaged LET (LET-d) were determined. For both quantities, two sub-types of averages were calculated, either considering the contributions from primary and secondary protons or from all protons and heavier, charged particles. Both simulated and experimental data were used in combination with a phenomenological model to estimate the relative biological effectiveness (RBE).Main results.All types ofLET-could be assessed with the luminescence detectors. The experimental determination ofLET-fis in agreement with reference data obtained from simulations across all measurement techniques and types of averaging. On the other hand,LET-dcan present challenges as a radiation quality metric to describe the detector response in mixed particle fields. However, excluding secondaries heavier than protons from theLET-dcalculation, as their contribution to the luminescence is suppressed by ionization quenching, leads to equal accuracy betweenLET-fandLET-d. Assessment of RBE through the experimentally determinedLET-dvalues agrees with independently acquired reference values, indicating that the investigated detectors can determineLET-with sufficient accuracy for proton therapy.Significance.OSLDs, TLDs, and FNTDs can be used to determineLET-and RBE in proton therapy. With the capability to determine dose through ionization quenching corrections derived fromLET-, OSLDs and TLDs can simultaneously ascertain dose,LET-, and RBE. This makes passive detectors appealing for measurements in phantoms to facilitate validation of clinical treatment plans or experiments related to proton therapy.
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Affiliation(s)
- Iván Domingo Muñoz
- Department of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany
- Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | | | - Alessio Parisi
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida, United States of America
| | - Niels Bassler
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Leszek Grzanka
- Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN), Kraków, Poland
| | | | - Ana Vaniqui
- Belgian Nuclear Research Center (SCK CEN), Mol, Belgium
| | - Paweł Olko
- Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN), Kraków, Poland
| | - Michał Sądel
- Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN), Kraków, Poland
| | - Liliana Stolarczyk
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Anne Vestergaard
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Oliver Jäkel
- Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
- Department of Radiation Oncology, Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg University Hospital, Heidelberg, Germany
| | | | - Jeppe Brage Christensen
- Department of Radiation Safety and Security, Paul Scherrer Institute (PSI), Villigen PSI, Switzerland
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Jeong S, Kim CE, Kim C, Pak SI, An S, Cheon W, Shin D, Lim YK, Jeong JH, Kim H, Chung Y, Choi SH, Lee SB. Feasibility study for the development of multilayered solar cells for proton linear energy transfer depth profile measurement. Med Phys 2024. [PMID: 38828894 DOI: 10.1002/mp.17234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 05/09/2024] [Accepted: 05/10/2024] [Indexed: 06/05/2024] Open
Abstract
BACKGROUND Previous study proposed a method to measure linear energy transfer (LET) at specific points using the quenching magnitude of thin film solar cells. This study was conducted to propose a more advanced method for measuring the LET distribution. PURPOSE This study focuses on evaluating the feasibility of estimating the proton LET distribution in proton therapy. The feasibility of measuring the proton LET and dose distribution simultaneously using a single-channel configuration comprising two solar cells with distinct quenching constants is investigated with the objective of paving the way for enhanced proton therapy dosimetry. METHODS Two solar cells with different quenching constants were used to estimate the proton LET distribution. Detector characteristics (e.g., dose linearity and dose-rate dependency) of the solar cells were evaluated to assess their suitability for dosimetry applications. First, using a reference beam condition, the quenching constants of the two solar cells were determined according to the modified Birks equation. The signal ratios of the two solar cells were then evaluated according to proton LET in relation to the estimated quenching constants. The proton LET distributions of six test beams were obtained by measuring the signal ratios of the two solar cells at each depth, and the ratios were evaluated by comparing them with those calculated by Monte Carlo simulation. RESULTS The detector characterization of the two solar cells including dose linearity and dose-rate dependence affirmed their suitability for use in dosimetry applications. The maximum difference between the LET measured using the two solar cells and that calculated by Monte Carlo simulation was 2.34 keV/µm. In the case of the dose distribution measured using the method proposed in this study, the maximum difference between range measured using the proposed method and that measured using a multilayered ionization chamber was 0.7 mm. The expected accuracy of simultaneous LET and dose distribution measurement using the method proposed in this study were estimated to be 3.82%. The signal ratios of the two solar cells, which are related to quenching constants, demonstrated the feasibility of measuring LET and dose distribution simultaneously. CONCLUSION The feasibility of measuring proton LET and dose distribution simultaneously using two solar cells with different quenching constants was demonstrated. Although the method proposed in this study was evaluated using a single channel by varying the measuring depth, the results suggest that the proton LET and dose distribution can be simultaneously measured if the detector is configured in a multichannel form. We believe that the results presented in this study provide the envisioned transition to a multichannel configuration, with the promise of substantially advancing proton therapy's accuracy and efficacy in cancer treatment.
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Affiliation(s)
- Seonghoon Jeong
- Department of Neurosurgery, College of Medicine, Ilsan Paik Hospital, Inje University, Goyang, Republic of Korea
| | - Chae-Eon Kim
- Proton Therapy Center, National Cancer Center, Goyang, Republic of Korea
- Department of Nuclear Engineering, Hanyang University, Seoul, Republic of Korea
| | - Chankyu Kim
- Proton Therapy Center, National Cancer Center, Goyang, Republic of Korea
| | - Sang-Il Pak
- Proton Therapy Center, National Cancer Center, Goyang, Republic of Korea
| | - Seohyeon An
- Proton Therapy Center, National Cancer Center, Goyang, Republic of Korea
- Department of Physics, Hanyang University, Seoul, Republic of Korea
| | - Wonjoong Cheon
- Department of Radiation Oncology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Dongho Shin
- Proton Therapy Center, National Cancer Center, Goyang, Republic of Korea
| | - Young Kyung Lim
- Proton Therapy Center, National Cancer Center, Goyang, Republic of Korea
| | - Jong Hwi Jeong
- Proton Therapy Center, National Cancer Center, Goyang, Republic of Korea
| | - Haksoo Kim
- Proton Therapy Center, National Cancer Center, Goyang, Republic of Korea
| | - Yoonsun Chung
- Department of Nuclear Engineering, Hanyang University, Seoul, Republic of Korea
| | - Sang Hyoun Choi
- Radiation Therapy Technology and Standards, Korea Institute of Radiological & Medical Sciences, Seoul, Republic of Korea
| | - Se Byeong Lee
- Proton Therapy Center, National Cancer Center, Goyang, Republic of Korea
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8
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Li W, Lin Y, Li HH, Shen X, Chen RC, Gao H. Biological optimization for hybrid proton-photon radiotherapy. Phys Med Biol 2024; 69:10.1088/1361-6560/ad4d51. [PMID: 38759678 PMCID: PMC11260294 DOI: 10.1088/1361-6560/ad4d51] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 05/17/2024] [Indexed: 05/19/2024]
Abstract
Objective.Hybrid proton-photon radiotherapy (RT) is a cancer treatment option to broaden access to proton RT. Additionally, with a refined treatment planning method, hybrid RT has the potential to offer superior plan quality compared to proton-only or photon-only RT, particularly in terms of target coverage and sparing organs-at-risk (OARs), when considering robustness to setup and range uncertainties. However, there is a concern regarding the underestimation of the biological effect of protons on OARs, especially those in close proximity to targets. This study seeks to develop a hybrid treatment planning method with biological dose optimization, suitable for clinical implementation on existing proton and photon machines, with each photon or proton treatment fraction delivering a uniform target dose.Approach.The proposed hybrid biological dose optimization method optimized proton and photon plan variables, along with the number of fractions for each modality, minimizing biological dose to the OARs and surrounding normal tissues. To mitigate underestimation of hot biological dose spots, proton biological dose was minimized within a ring structure surrounding the target. Hybrid plans were designed to be deliverable separately and robustly on existing proton and photon machines, with enforced uniform target dose constraints for the proton and photon fraction doses. A probabilistic formulation was utilized for robust optimization of setup and range uncertainties for protons and photons. The nonconvex optimization problem, arising from minimum monitor unit constraint and dose-volume histogram constraints, was solved using an iterative convex relaxation method.Main results.Hybrid planning with biological dose optimization effectively eliminated hot spots of biological dose, particularly in normal tissues surrounding the target, outperforming proton-only planning. It also provided superior overall plan quality and OAR sparing compared to proton-only or photon-only planning strategies.Significance.This study presents a novel hybrid biological treatment planning method capable of generating plans with reduced biological hot spots, superior plan quality to proton-only or photon-only plans, and clinical deliverability on existing proton and photon machines, separately and robustly.
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Affiliation(s)
- Wangyao Li
- Department of Radiation Oncology, Radiation Oncology, University of Kansas Medical Center, Kansas City, KS 66160, United States of America
| | - Yuting Lin
- Department of Radiation Oncology, Radiation Oncology, University of Kansas Medical Center, Kansas City, KS 66160, United States of America
| | - Harold H Li
- Department of Radiation Oncology, Radiation Oncology, University of Kansas Medical Center, Kansas City, KS 66160, United States of America
| | - Xinglei Shen
- Department of Radiation Oncology, Radiation Oncology, University of Kansas Medical Center, Kansas City, KS 66160, United States of America
| | - Ronald C Chen
- Department of Radiation Oncology, Radiation Oncology, University of Kansas Medical Center, Kansas City, KS 66160, United States of America
| | - Hao Gao
- Department of Radiation Oncology, Radiation Oncology, University of Kansas Medical Center, Kansas City, KS 66160, United States of America
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9
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Holtzman AL, Mohammadi H, Furutani KM, Koffler DM, McGee LA, Lester SC, Gamez ME, Routman DM, Beltran CJ, Liang X. Impact of Relative Biologic Effectiveness for Proton Therapy for Head and Neck and Skull-Base Tumors: A Technical and Clinical Review. Cancers (Basel) 2024; 16:1947. [PMID: 38893068 PMCID: PMC11171304 DOI: 10.3390/cancers16111947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 05/17/2024] [Accepted: 05/18/2024] [Indexed: 06/21/2024] Open
Abstract
Proton therapy has emerged as a crucial tool in the treatment of head and neck and skull-base cancers, offering advantages over photon therapy in terms of decreasing integral dose and reducing acute and late toxicities, such as dysgeusia, feeding tube dependence, xerostomia, secondary malignancies, and neurocognitive dysfunction. Despite its benefits in dose distribution and biological effectiveness, the application of proton therapy is challenged by uncertainties in its relative biological effectiveness (RBE). Overcoming the challenges related to RBE is key to fully realizing proton therapy's potential, which extends beyond its physical dosimetric properties when compared with photon-based therapies. In this paper, we discuss the clinical significance of RBE within treatment volumes and adjacent serial organs at risk in the management of head and neck and skull-base tumors. We review proton RBE uncertainties and its modeling and explore clinical outcomes. Additionally, we highlight technological advancements and innovations in plan optimization and treatment delivery, including linear energy transfer/RBE optimizations and the development of spot-scanning proton arc therapy. These advancements show promise in harnessing the full capabilities of proton therapy from an academic standpoint, further technological innovations and clinical outcome studies, however, are needed for their integration into routine clinical practice.
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Affiliation(s)
- Adam L. Holtzman
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Homan Mohammadi
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Keith M. Furutani
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Daniel M. Koffler
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Lisa A. McGee
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, USA
| | - Scott C. Lester
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Mauricio E. Gamez
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - David M. Routman
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Chris J. Beltran
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Xiaoying Liang
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA
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10
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Gardner LL, O'Connor JD, McMahon SJ. Benchmarking proton RBE models. Phys Med Biol 2024; 69:085022. [PMID: 38471187 DOI: 10.1088/1361-6560/ad3329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 03/12/2024] [Indexed: 03/14/2024]
Abstract
Objective.To biologically optimise proton therapy, models which can accurately predict variations in proton relative biological effectiveness (RBE) are essential. Current phenomenological models show large disagreements in RBE predictions, due to different model assumptions and differences in the data to which they were fit. In this work, thirteen RBE models were benchmarked against a comprehensive proton RBE dataset to evaluate predictions when all models are fit using the same data and fitting techniques, and to assess the statistical robustness of the models.Approach.Model performance was initially evaluated by fitting to the full dataset, and then a cross-validation approach was applied to assess model generalisability and robustness. The impact of weighting the fit and the choice of biological endpoint (either single or multiple survival levels) was also evaluated.Main results.Fitting the models to a common dataset reduced differences between their predictions, however significant disagreements remained due to different underlying assumptions. All models performed poorly under cross-validation in the weighted fits, suggesting that some uncertainties on the experimental data were significantly underestimated, resulting in over-fitting and poor performance on unseen data. The simplest model, which depends linearly on the LET but has no tissue or dose dependence, performed best for a single survival level. However, when fitting to multiple survival levels simultaneously, more complex models with tissue dependence performed better. All models had significant residual uncertainty in their predictions compared to experimental data.Significance.This analysis highlights that poor quality of error estimation on the dose response parameters introduces substantial uncertainty in model fitting. The significant residual error present in all approaches illustrates the challenges inherent in fitting to large, heterogeneous datasets and the importance of robust statistical validation of RBE models.
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Affiliation(s)
- Lydia L Gardner
- Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, United Kingdom
| | - John D O'Connor
- School of Engineering, Ulster University, Belfast, United Kingdom
| | - Stephen J McMahon
- Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, United Kingdom
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11
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Selva A, Bianchi A, Cirrone GAP, Petringa G, Romano F, Schettino G, Conte V. Sensitivity of a mini-TEPC to radiation quality variations in clinical proton beams. Phys Med 2024; 118:103201. [PMID: 38199179 DOI: 10.1016/j.ejmp.2023.103201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 10/30/2023] [Accepted: 12/21/2023] [Indexed: 01/12/2024] Open
Abstract
PURPOSE This work aims at studying the sensitivity of a miniaturized Tissue-Equivalent Proportional Counter to variations of beam quality in clinical radiation fields, to further investigate its performances as radiation quality monitor. METHODS Measurements were taken at the CATANA facility (INFN-LNS, Catania, Italy), in a monoenergetic and an energy-modulated proton beam with the same initial energy of 62 MeV. PMMA layers were placed in front of the detector to measure at different depths along the depth-dose profile. The frequency- and dose-mean lineal energy were compared to the track- and dose-averaged LET calculated by Monte Carlo simulations. A microdosimetric evaluation of the Relative Biological Effectiveness (RBE) was performed and compared with cell survival experiments. RESULTS Microdosimetric distributions measured at identical depths in the two beams show spectral differences reflecting their different radiation quality. Discrepancies are most evident at depths corresponding to the Spread-Out Bragg Peak, while spectra at the entrance and in the dose fall-off regions are similar. This can be explained by the different energy components that compose the pristine and spread-out peaks at each depth. The trend of microdosimetric mean values matches that of calculated LET averages along the entire penetration depth, and the microdosimetric estimation of RBE is consistent with radiobiological data not only at 2 Gy but also at lower dose levels, such as those absorbed by healthy tissues. CONCLUSIONS The mini-TEPC is sensitive to differences in radiation quality resulting from different modulations of the proton beam, confirming its potential for beam quality monitoring in proton therapy.
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Affiliation(s)
- A Selva
- INFN Laboratori Nazionali di Legnaro, Legnaro, Italy.
| | - A Bianchi
- INFN Laboratori Nazionali di Legnaro, Legnaro, Italy
| | | | - G Petringa
- INFN Laboratori Nazionali del Sud, Catania, Italy
| | - F Romano
- INFN Sezione di Catania, Catania, Italy
| | - G Schettino
- National Physical Laboratory, Medical Radiation Science, Teddington, UK
| | - V Conte
- INFN Laboratori Nazionali di Legnaro, Legnaro, Italy
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12
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Moteabbed M, Bobić M, Paganetti H, Efstathiou JA. The Role of Proton Therapy for Prostate Cancer in the Setting of Hip Prosthesis. Cancers (Basel) 2024; 16:330. [PMID: 38254818 PMCID: PMC10813677 DOI: 10.3390/cancers16020330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/02/2024] [Accepted: 01/05/2024] [Indexed: 01/24/2024] Open
Abstract
PURPOSE Given that the current standard of proton therapy (PT) for prostate cancer is through bilateral beams, this modality is typically avoided when it comes to treatment of patients with hip prosthesis. The purpose of this study was to evaluate whether novel PT methods, i.e., anterior proton beams and proton arc therapy (PArc), could be feasible options to treat this patient subpopulation. We evaluate PT methods in the context of dosimetry and robustness and compare with standard of practice volumetric modulated arc therapy (VMAT) to explore any potential benefits. METHODS Two PT and one VMAT treatment plans were retrospectively created for 10 patients who participated in a clinical trial with a weekly repeat CT (rCT) imaging component. All plans were robustly optimized and featured: (1) combination anterior oblique and lateral proton beams (AoL), (2) PArc, and (3) VMAT. All patients had hydrogel spacers in place, which enabled safe application of anterior proton beams. The planned dose was 70 Gy (RBE) to the entire prostate gland and 50 Gy (RBE) to the proximal seminal vesicles in 28 fractions. Along with plan dose-volume metrics, robustness to setup and interfractional variations were evaluated using the weekly rCT images. The linear energy transfer (LET)-weighted dose was evaluated for PArc plans to ensure urethra sparing given the typical high-LET region at the end of range. RESULTS Both PT methods were dosimetrically feasible and provided reduction of some key OAR metrics compared to VMAT except for penile bulb, while providing equally good target coverage. Significant differences in median rectum V35 (22-25%), penile bulb Dmean (5 Gy), rectum V61 (2%), right femoral head Dmean (5 Gy), and bladder V39 (4%) were found between PT and VMAT. All plans were equally robust to variations. LET-weighted dose in urethra was equivalent to the physical dose for PArc plans and hence no added urethral toxicity was expected. CONCLUSIONS PT for treatment of prostate cancer patients with hip prosthesis is feasible and equivalent or potentially superior to VMAT in quality in some cases. The choice of radiotherapy regimen can be personalized based on patient characteristics to achieve the best treatment outcome.
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Affiliation(s)
- Maryam Moteabbed
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA (J.A.E.)
| | - Mislav Bobić
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA (J.A.E.)
- Department of Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - Harald Paganetti
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA (J.A.E.)
| | - Jason A. Efstathiou
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA (J.A.E.)
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Goudarzi HM, Lim G, Grosshans D, Mohan R, Cao W. Incorporating variable RBE in IMPT optimization for ependymoma. J Appl Clin Med Phys 2024; 25:e14207. [PMID: 37985962 PMCID: PMC10795446 DOI: 10.1002/acm2.14207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 10/19/2023] [Accepted: 10/28/2023] [Indexed: 11/22/2023] Open
Abstract
PURPOSE To study the dosimetric impact of incorporating variable relative biological effectiveness (RBE) of protons in optimizing intensity-modulated proton therapy (IMPT) treatment plans and to compare it with conventional constant RBE optimization and linear energy transfer (LET)-based optimization. METHODS This study included 10 pediatric ependymoma patients with challenging anatomical features for treatment planning. Four plans were generated for each patient according to different optimization strategies: (1) constant RBE optimization (ConstRBEopt) considering standard-of-care dose requirements; (2) LET optimization (LETopt) using a composite cost function simultaneously optimizing dose-averaged LET (LETd ) and dose; (3) variable RBE optimization (VarRBEopt) using a recent phenomenological RBE model developed by McNamara et al.; and (4) hybrid RBE optimization (hRBEopt) assuming constant RBE for the target and variable RBE for organs at risk. By normalizing each plan to obtain the same target coverage in either constant or variable RBE, we compared dose, LETd , LET-weighted dose, and equivalent uniform dose between the different optimization approaches. RESULTS We found that the LETopt plans consistently achieved increased LET in tumor targets and similar or decreased LET in critical organs compared to other plans. On average, the VarRBEopt plans achieved lower mean and maximum doses with both constant and variable RBE in the brainstem and spinal cord for all 10 patients. To compensate for the underdosing of targets with 1.1 RBE for the VarRBEopt plans, the hRBEopt plans achieved higher physical dose in targets and reduced mean and especially maximum variable RBE doses compared to the ConstRBEopt and LETopt plans. CONCLUSION We demonstrated the feasibility of directly incorporating variable RBE models in IMPT optimization. A hybrid RBE optimization strategy showed potential for clinical implementation by maintaining all current dose limits and reducing the incidence of high RBE in critical normal tissues in ependymoma patients.
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Affiliation(s)
| | - Gino Lim
- Department of Industrial EngineeringUniversity of HoustonHoustonTexasUSA
| | - David Grosshans
- Department of Radiation OncologyThe University of Texas MD Anderson Cancer CenterHoustonTexasUSA
| | - Radhe Mohan
- Department of Radiation PhysicsThe University of Texas MD Anderson Cancer CenterHoustonTexasUSA
| | - Wenhua Cao
- Department of Radiation PhysicsThe University of Texas MD Anderson Cancer CenterHoustonTexasUSA
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Heuchel L, Hahn C, Ödén J, Traneus E, Wulff J, Timmermann B, Bäumer C, Lühr A. The dirty and clean dose concept: Towards creating proton therapy treatment plans with a photon-like dose response. Med Phys 2024; 51:622-636. [PMID: 37877574 DOI: 10.1002/mp.16809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 10/11/2023] [Accepted: 10/11/2023] [Indexed: 10/26/2023] Open
Abstract
BACKGROUND Applying tolerance doses for organs at risk (OAR) from photon therapy introduces uncertainties in proton therapy when assuming a constant relative biological effectiveness (RBE) of 1.1. PURPOSE This work introduces the novel dirty and clean dose concept, which allows for creating treatment plans with a more photon-like dose response for OAR and, thus, less uncertainties when applying photon-based tolerance doses. METHODS The concept divides the 1.1-weighted dose distribution into two parts: the clean and the dirty dose. The clean and dirty dose are deposited by protons with a linear energy transfer (LET) below and above a set LET threshold, respectively. For the former, a photon-like dose response is assumed, while for the latter, the RBE might exceed 1.1. To reduce the dirty dose in OAR, a MaxDirtyDose objective was added in treatment plan optimization. It requires setting two parameters: LET threshold and max dirty dose level. A simple geometry consisting of one target volume and one OAR in water was used to study the reduction in dirty dose in the OAR depending on the choice of the two MaxDirtyDose objective parameters during plan optimization. The best performing parameter combinations were used to create multiple dirty dose optimized (DDopt) treatment plans for two cranial patient cases. For each DDopt plan, 1.1-weighted dose, variable RBE-weighted dose using the Wedenberg RBE model and dose-average LETd distributions as well as resulting normal tissue complication probability (NTCP) values were calculated and compared to the reference plan (RefPlan) without MaxDirtyDose objectives. RESULTS In the water phantom studies, LET thresholds between 1.5 and 2.5 keV/µm yielded the best plans and were subsequently used. For the patient cases, nearly all DDopt plans led to a reduced Wedenberg dose in critical OAR. This reduction resulted from an LET reduction and translated into an NTCP reduction of up to 19 percentage points compared to the RefPlan. The 1.1-weighted dose in the OARs was slightly increased (patient 1: 0.45 Gy(RBE), patient 2: 0.08 Gy(RBE)), but never exceeded clinical tolerance doses. Additionally, slightly increased 1.1-weighted dose in healthy brain tissue was observed (patient 1: 0.81 Gy(RBE), patient 2: 0.53 Gy(RBE)). The variation of NTCP values due to variation of α/β from 2 to 3 Gy was much smaller for DDopt (2 percentage points (pp)) than for RefPlans (5 pp). CONCLUSIONS The novel dirty and clean dose concept allows for creating biologically more robust proton treatment plans with a more photon-like dose response. The reduced uncertainties in RBE can, therefore, mitigate uncertainties introduced by using photon-based tolerance doses for OAR.
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Affiliation(s)
- Lena Heuchel
- Department of Physics, TU Dortmund University, Dortmund, Germany
| | - Christian Hahn
- Department of Physics, TU Dortmund University, Dortmund, Germany
- OncoRay-National Center of Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Jakob Ödén
- RaySearch Laboratories AB, Stockholm, Sweden
| | | | - Jörg Wulff
- West German Proton Therapy Center Essen, Essen, Germany
- West German Cancer Center (WTZ), University Hospital Essen, Essen, Germany
| | - Beate Timmermann
- West German Proton Therapy Center Essen, Essen, Germany
- West German Cancer Center (WTZ), University Hospital Essen, Essen, Germany
- Department of Particle Therapy, University Hospital Essen, Essen, Germany
- German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Essen, Germany
| | - Christian Bäumer
- Department of Physics, TU Dortmund University, Dortmund, Germany
- West German Proton Therapy Center Essen, Essen, Germany
- West German Cancer Center (WTZ), University Hospital Essen, Essen, Germany
- German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Essen, Germany
| | - Armin Lühr
- Department of Physics, TU Dortmund University, Dortmund, Germany
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15
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Huerta-Juan Y, Xicohténcatl-Hernández N, Massillon-Jl G. Linear energy transfer (LET) distribution outside small radiotherapy field edges produced by 6 MV X-rays. Sci Rep 2023; 13:21466. [PMID: 38052891 PMCID: PMC10697984 DOI: 10.1038/s41598-023-44409-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 10/07/2023] [Indexed: 12/07/2023] Open
Abstract
In modern radiotherapy with photons, the absorbed dose outside the radiation field is generally investigated. But it is well known that the biological damage depends not only on the absorbed dose but also on LET. This work investigated the dose-average LET (LΔ,D) outside several small radiotherapy fields to provide information that can help for better evaluating the biological effect in organs at risk close to the tumour volume. The electron fluences produced in liquid water by a 6 MV X-rays Varian iX linac were calculated using the EGSnrc Monte Carlo code. With the electron spectra, LΔ,D calculations were made for eight open small square fields and the reference field at water depths of 0.15 cm, 1.35 cm, 9.85 cm and 19.85 cm and several off-axis distances. The variation of LΔ,D from the centre of the beam to 2 cm outside the field's edge depends on the field size and water depth. Using radiobiological data reported in the literature for chromosomal aberrations as an endpoint for the induction of dicentrics determined in Human Lymphocytes, we estimated the maximum low-dose relative biological effectiveness, (RBEM) finding an increase of up to 100% from the centre of the beam to 2 cm from the field's edge.
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Affiliation(s)
- Y Huerta-Juan
- Instituto de Física, Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico
| | - N Xicohténcatl-Hernández
- Instituto de Física, Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico
- Departamento de Matemáticas, Universidad Popular Autónoma del Estado de Puebla, 72410, Puebla, Mexico
| | - G Massillon-Jl
- Instituto de Física, Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico.
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16
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Fredriksson A, Glimelius L, Bokrantz R. The LET trilemma: Conflicts between robust target coverage, uniform dose, and dose-averaged LET in carbon therapy. Med Phys 2023; 50:7338-7348. [PMID: 37820319 DOI: 10.1002/mp.16771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 08/28/2023] [Accepted: 09/15/2023] [Indexed: 10/13/2023] Open
Abstract
BACKGROUND Linear energy transfer (LET) is closely related to the biological effect of ionizing radiation. Increasing the dose-averaged LET (LETd ) within the target volume has been proposed as a means to improve clinical outcome for hypoxic tumors. However, doing so can lead to reduced robustness to range uncertainty. PURPOSE To quantify the relationship between robust target coverage, target dose uniformity, and LETd , we employ robust optimization using dose-based and LETd -based functions and allow varying amounts of target non-uniformity. METHODS AND MATERIALS Robust carbon therapy optimization is used to create plans for phantom cases with increasing target sizes (radii 1, 3, and 5 cm). First, the influence of respectively range and setup uncertainty on the LETd in the target is studied. Second, we employ strategies allowing overdosage in the clinical target volume (CTV) or gross tumor volume (GTV), which enable increased LETd in the target. The relationship between robust target coverage and LETd in the target is illustrated by tradeoff curves generated by optimization using varying weights for the LETd -based functions. RESULTS As the range uncertainty used in the robust optimization increased from 0% to 5%, the near-minimum nominal LETd decreased by 17%-29% (9-21 keV/µm) for the different target sizes. The effect of increasing setup uncertainty was marginal. Allowing 10% overdosage in the CTV enabled 9%-29% (6-12 keV/µm) increased near-minimum worst case LETd for the different target sizes, compared to uniform dose plans. When 10% overdosage was allowed in the GTV only, the increase was 1%-20% (1-8 keV/µm). CONCLUSIONS There is an inherent conflict between range uncertainty robustness and high LETd in the target, which is aggravated with increasing target size. For large tumors, it is possible to simultaneously achieve two of the three qualities range robustness, uniform dose, and high LETd in the target.
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Henjum H, Tjelta J, Fjæra LF, Pilskog S, Stokkevåg CH, Lyngholm E, Handeland AH, Ytre-Hauge KS. Influence of beam pruning techniques on LET and RBE in proton arc therapy. Front Oncol 2023; 13:1155310. [PMID: 37731633 PMCID: PMC10508957 DOI: 10.3389/fonc.2023.1155310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 08/15/2023] [Indexed: 09/22/2023] Open
Abstract
Introduction Proton arc therapy (PAT) is an emerging treatment modality that holds promise to improve target volume coverage and reduce linear energy transfer (LET) in organs at risk. We aimed to investigate if pruning the highest energy layers in each beam direction could increase the LET in the target and reduce LET in tissue and organs at risk (OAR) surrounding the target volume, thus reducing the relative biological effectiveness (RBE)-weighted dose and sparing healthy tissue. Methods PAT plans for a germinoma, an ependymoma and a rhabdomyosarcoma patient were created in the Eclipse treatment planning system with a prescribed dose of 54 Gy(RBE) using a constant RBE of 1.1 (RBE1.1). The PAT plans was pruned for high energy spots, creating several PAT plans with different amounts of pruning while maintaining tumor coverage, denoted PX-PAT plans, where X represents the amount of pruning. All plans were recalculated in the FLUKA Monte Carlo software, and the LET, physical dose, and variable RBE-weighted dose from the phenomenological Rørvik (ROR) model and an LET weighted dose (LWD) model were evaluated. Results and discussion For the germinoma case, all plans but the P6-PAT reduced the mean RBE-weighted dose to the surrounding healthy tissue compared to the PAT plan. The LET was increasingly higher within the PTV for each pruning iteration, where the mean LET from the P6-PAT plan was 1.5 keV / μm higher than for the PAT plan, while the P4- and P5-PAT plans provided an increase of 0.4 and 0.7 keV / μm , respectively. The other plans increased the LET by a smaller margin compared to the PAT plan. Likewise, the LET values to the healthy tissue were reduced for each degree of pruning. Similar results were found for the ependymoma and the rhabdomyosarcoma case. We demonstrated a PAT pruning technique that can increase both LET and RBE in the target volume and at the same time decreased values in healthy tissue, without affecting the target volume dose coverage.
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Affiliation(s)
- Helge Henjum
- Department of Physics and Technology, University of Bergen, Bergen, Norway
| | - Johannes Tjelta
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| | - Lars Fredrik Fjæra
- Department of Physics and Technology, University of Bergen, Bergen, Norway
| | - Sara Pilskog
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| | - Camilla H. Stokkevåg
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| | - Erlend Lyngholm
- Department of Physics and Technology, University of Bergen, Bergen, Norway
| | - Andreas H. Handeland
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
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McIntyre M, Wilson P, Gorayski P, Bezak E. A Systematic Review of LET-Guided Treatment Plan Optimisation in Proton Therapy: Identifying the Current State and Future Needs. Cancers (Basel) 2023; 15:4268. [PMID: 37686544 PMCID: PMC10486456 DOI: 10.3390/cancers15174268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/16/2023] [Accepted: 08/17/2023] [Indexed: 09/10/2023] Open
Abstract
The well-known clinical benefits of proton therapy are achieved through higher target-conformality and normal tissue sparing than conventional radiotherapy. However, there is an increased sensitivity to uncertainties in patient motion/setup, proton range and radiobiological effect. Although recent efforts have mitigated some uncertainties, radiobiological effect remains unresolved due to a lack of clinical data for relevant endpoints. Therefore, RBE optimisations may be currently unsuitable for clinical treatment planning. LET optimisation is a novel method that substitutes RBE with LET, shifting LET hotspots outside critical structures. This review outlines the current status of LET optimisation in proton therapy, highlighting knowledge gaps and possible future research. Following the PRISMA 2020 guidelines, a search of the MEDLINE® and Scopus databases was performed in July 2023, identifying 70 relevant articles. Generally, LET optimisation methods achieved their treatment objectives; however, clinical benefit is patient-dependent. Inconsistencies in the reported data suggest further testing is required to identify therapeutically favourable methods. We discuss the methods which are suitable for near-future clinical deployment, with fast computation times and compatibility with existing treatment protocols. Although there is some clinical evidence of a correlation between high LET and adverse effects, further developments are needed to inform future patient selection protocols for widespread application of LET optimisation in proton therapy.
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Affiliation(s)
- Melissa McIntyre
- Allied Health & Human Performance Academic Unit, University of South Australia, Adelaide, SA 5000, Australia
| | - Puthenparampil Wilson
- Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide, SA 5000, Australia
- UniSA STEM, University of South Australia, Adelaide, SA 5000, Australia
| | - Peter Gorayski
- Allied Health & Human Performance Academic Unit, University of South Australia, Adelaide, SA 5000, Australia
- Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide, SA 5000, Australia
- Australian Bragg Centre for Proton Therapy and Research, Adelaide, SA 5000, Australia
| | - Eva Bezak
- Allied Health & Human Performance Academic Unit, University of South Australia, Adelaide, SA 5000, Australia
- Department of Physics, University of Adelaide, Adelaide, SA 5005, Australia
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Henthorn NT, Gardner LL, Aitkenhead AH, Rowland BC, Shin J, Smith EAK, Merchant MJ, Mackay RI, Kirkby KJ, Chaudhary P, Prise KM, McMahon SJ, Underwood TSA. Proposing a Clinical Model for RBE Based on Proton Track-End Counts. Int J Radiat Oncol Biol Phys 2023; 116:916-926. [PMID: 36642109 DOI: 10.1016/j.ijrobp.2022.12.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 12/21/2022] [Accepted: 12/29/2022] [Indexed: 01/15/2023]
Abstract
PURPOSE In proton therapy, the clinical application of linear energy transfer (LET) optimization remains contentious, in part because of challenges associated with the definition and calculation of LET and its exact relationship with relative biological effectiveness (RBE) because of large variation in experimental in vitro data. This has raised interest in other metrics with favorable properties for biological optimization, such as the number of proton track ends in a voxel. In this work, we propose a novel model for clinical calculations of RBE, based on proton track end counts. METHODS AND MATERIALS We developed an effective dose concept to translate between the total proton track-end count per unit mass in a voxel and a proton RBE value. Dose, track end, and dose-averaged LET (LETd) distributions were simulated using Monte Carlo models for a series of water phantoms, in vitro radiobiological studies, and patient treatment plans. We evaluated the correlation between track ends and regions of elevated biological effectiveness in comparison to LETd-based models of RBE. RESULTS Track ends were found to correlate with biological effects in in vitro experiments with an accuracy comparable to LETd. In patient simulations, our track end model identified the same biological hotspots as predicted by LETd-based radiobiological models of proton RBE. CONCLUSIONS These results suggest that, for clinical optimization and evaluation, an RBE model based on proton track end counts may match LETd-based models in terms of information provided while also offering superior statistical properties.
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Affiliation(s)
- Nicholas T Henthorn
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Manchester, United Kingdom.
| | - Lydia L Gardner
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, United Kingdom
| | - Adam H Aitkenhead
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Benjamin C Rowland
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Jungwook Shin
- Department of Radiation Oncology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts
| | - Edward A K Smith
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Michael J Merchant
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Ranald I Mackay
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Karen J Kirkby
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Pankaj Chaudhary
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, United Kingdom
| | - Kevin M Prise
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, United Kingdom
| | - Stephen J McMahon
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, United Kingdom
| | - Tracy S A Underwood
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Manchester, United Kingdom; Leo Cancer Care Ltd, Unit 1 Woodbridge House, Chapel Rd, Smallfield, Horley RH6 9NW, United Kingdom
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20
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Cao W, Li Y, Zhang X, Poenisch F, Yepes P, Sahoo N, Grosshans D, McGovern S, Gunn GB, Frank SJ, Zhu XR. Intensity modulated proton arc therapy via geometry-based energy selection for ependymoma. J Appl Clin Med Phys 2023:e13954. [PMID: 36913484 DOI: 10.1002/acm2.13954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 02/06/2023] [Accepted: 02/14/2023] [Indexed: 03/14/2023] Open
Abstract
PURPOSE We developed and tested a novel method of creating intensity modulated proton arc therapy (IMPAT) plans that uses computing resources similar to those for regular intensity-modulated proton therapy (IMPT) plans and may offer a dosimetric benefit for patients with ependymoma or similar tumor geometries. METHODS Our IMPAT planning method consists of a geometry-based energy selection step with major scanning spot contributions as inputs computed using ray-tracing and single-Gaussian approximation of lateral spot profiles. Based on the geometric relation of scanning spots and dose voxels, our energy selection module selects a minimum set of energy layers at each gantry angle such that each target voxel is covered by sufficient scanning spots as specified by the planner, with dose contributions above the specified threshold. Finally, IMPAT plans are generated by robustly optimizing scanning spots of the selected energy layers using a commercial proton treatment planning system (TPS). The IMPAT plan quality was assessed for four ependymoma patients. Reference three-field IMPT plans were created with similar planning objective functions and compared with the IMPAT plans. RESULTS In all plans, the prescribed dose covered 95% of the clinical target volume (CTV) while maintaining similar maximum doses for the brainstem. While IMPAT and IMPT achieved comparable plan robustness, the IMPAT plans achieved better homogeneity and conformity than the IMPT plans. The IMPAT plans also exhibited higher relative biological effectiveness (RBE) enhancement than did the corresponding reference IMPT plans for the CTV in all four patients and brainstem in three of them. CONCLUSIONS The proposed method demonstrated potential as an efficient technique for IMPAT planning and may offer a dosimetric benefit for patients with ependymoma or tumors in close proximity to critical organs. IMPAT plans created using this method had elevated RBE enhancement associated with increased linear energy transfer (LET) in both targets and abutting critical organs.
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Affiliation(s)
- Wenhua Cao
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Yupeng Li
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Xiaodong Zhang
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Falk Poenisch
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Pablo Yepes
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.,Department of Physics and Astronomy, Rice University, Houston, Texas, USA
| | - Narayan Sahoo
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - David Grosshans
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Susan McGovern
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - G Brandon Gunn
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Steven J Frank
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Xiaorong R Zhu
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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21
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de Jong BA, Battinelli C, Free J, Wagenaar D, Engwall E, Janssens G, Langendijk JA, Korevaar EW, Both S. Spot scanning proton arc therapy reduces toxicity in oropharyngeal cancer patients. Med Phys 2023; 50:1305-1317. [PMID: 36373893 DOI: 10.1002/mp.16098] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 07/28/2022] [Accepted: 10/24/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Proton arc technology has recently shown dosimetric gains for various treatment indications. The increased number of beams and energy layers (ELs) in proton arc plans, increases the degrees of freedom in plan optimization and thereby flexibility to spare dose in organs at risk (OARs). A relationship exists between dosimetric plan quality, delivery efficiency, the number of ELs -and beams in a proton arc plan. PURPOSE This work aims to investigate the effect of the number of beams and ELs in a proton arc plan, on toxicity and delivery time for oropharyngeal cancer patients (OPC) selected for intensity modulated proton therapy (IMPT) based on the Dutch model-based approach. METHODS The EL reduction algorithm iteratively selects ELs from beams equidistantly spaced over a 360° arc. The beams in the final plan may contain multiple ELs, making them suited for static delivery on the studied treatment machine. The produced plans can therefore be called "step and shoot" proton arc plans. The number of beams and ELs were varied to determine the relationship with the planning cost function value, normal tissue complication probability (NTCP) and delivery time. Proton arc plans with robust target coverage and optimal energy layer reduction (ELR) settings to reduce NTCP, were generated for 10 OPC patients. Proton arc plans were compared to clinical volumetric modulated arc therapy (VMAT) and IMPT plans in terms of integral dose, OAR dose, NTCP for xerostomia and dysphagia and delivery time. Furthermore, dose-weighted average linear energy transfer (LETd ) distributions were compared between the IMPT and proton arc plans. A dry run delivery of a plan containing 20 beams and 360 ELs was performed to evaluate delivery time and accuracy. RESULTS We found 360 ELs distributed over 30 beams generated proton arc plans with near minimal expected plan toxicity. Relative to corresponding IMPT and VMAT plans, an average reduction of 21 ± 3% and 58 ± 10% in integral dose was observed. D m e a n $_{mean}$ was reduced most in the pharyngeal constrictor muscle (PCM) medius structure, with on average 9.0 ± 4.2 Gy(RBE) (p = 0.0002) compared to the clinical IMPT plans. The average NTCP for grade≥2 and grade≥3 xerostomia at 6 months after treatment significantly decreased with 4.7 ± 1.8% (p = 0.002) and 1.7 ± 0.8% (p = 0.002), respectively, while the average NTCP for grade≥2 and grade≥3 dysphagia decreased with 4.4 ± 2.9% (p = 0.002) and 0.9 ± 0.4% (p = 0.002), respectively, increasing the benefit of protons relative to VMAT. For a "step and shoot" proton arc delivery with auto beam sequencing the estimated delivery time is 11 min, similar to the delivery time of a 6-field IMPT treatment. Gamma analysis between the planned and delivered dose distribution resulted in a 99.99% pass rate using 1mm/1% dose difference/distance to agreement criteria. CONCLUSIONS "Step and shoot" proton arc demonstrates potential to further reduce toxicity compared to IMPT and VMAT in OPC treatment. By employing 360 ELs and 30 beams in the proposed ELR method, delivery time can reach clinically acceptable levels without compromising plan toxicity when automatic beam sequencing is available.
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Affiliation(s)
- Bas A de Jong
- Department of Radiation Oncology, University Medical Center Groningen, Groningen, The Netherlands
| | | | - Jeffrey Free
- Department of Radiation Oncology, University Medical Center Groningen, Groningen, The Netherlands
| | - Dirk Wagenaar
- Department of Radiation Oncology, University Medical Center Groningen, Groningen, The Netherlands
| | - Erik Engwall
- Research and Development, RaySearch Laboratories AB, Stockholm, Sweden
| | - Guillaume Janssens
- Research and Development, Ion Beam Applications SA, Louvain-la-Neuve, Belgium
| | - Johannes A Langendijk
- Department of Radiation Oncology, University Medical Center Groningen, Groningen, The Netherlands
| | - Erik W Korevaar
- Department of Radiation Oncology, University Medical Center Groningen, Groningen, The Netherlands
| | - Stefan Both
- Department of Radiation Oncology, University Medical Center Groningen, Groningen, The Netherlands
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22
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Li W, Lin Y, Li H, Rotondo R, Gao H. An iterative convex relaxation method for proton LET optimization. Phys Med Biol 2023; 68:10.1088/1361-6560/acb88d. [PMID: 36731144 PMCID: PMC10037460 DOI: 10.1088/1361-6560/acb88d] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 02/01/2023] [Indexed: 02/04/2023]
Abstract
Objective:A constant relative biological effectiveness of 1.1 in current clinical practice of proton radiotherapy (RT) is a crude approximation and may severely underestimate the biological dose from proton RT to normal tissues, especially near the treatment target at the end of Bragg peaks that exhibits high linear energy transfer (LET). LET optimization can account for biological effectiveness of protons during treatment planning, for minimizing biological proton dose and hot spots to normal tissues. However, the LET optimization is usually nonlinear and nonconvex to solve, for which this work will develop an effective optimization method based on iterative convex relaxation (ICR).Approach: In contrast to the generic nonlinear optimization method, such as Quasi-Newton (QN) method, that does not account for specific characteristics of LET optimization, ICR is tailored to LET modeling and optimization in order to effectively and efficiently solve the LET problem. Specifically, nonlinear dose-averaged LET term is iteratively linearized and becomes convex during ICR, while nonconvex dose-volume constraint and minimum-monitor-unit constraint are also handled by ICR, so that the solution for LET optimization is obtained by solving a sequence of convex and linearized convex subproblems. Since the high LET mostly occurs near the target, a 1 cm normal-tissue expansion of clinical target volume (CTV) (excluding CTV), i.e. CTV1cm, is defined to as an auxiliary structure during treatment planning, where LET is minimized.Main results: ICR was validated in comparison with QN for abdomen, lung, and head-and-neck cases. ICR was effective for LET optimization, as ICR substantially reduced the LET and biological dose in CTV1cm the ring, with preserved dose conformality to CTV. Compared to QN, ICR had smaller LET, physical and biological dose in CTV1cm, and higher conformity index values; ICR was also computationally more efficient, which was about 3 times faster than QN.Significance: A LET-specific optimization method based on ICR has been developed for solving proton LET optimization, which has been shown to be more computationally efficient than generic nonlinear optimizer via QN, with better plan quality in terms of LET, biological and physical dose conformality.
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Affiliation(s)
- Wangyao Li
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, Kansas, KS 66160, United States of America
| | - Yuting Lin
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, Kansas, KS 66160, United States of America
| | - Harold Li
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, Kansas, KS 66160, United States of America
| | - Ronny Rotondo
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, Kansas, KS 66160, United States of America
| | - Hao Gao
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, Kansas, KS 66160, United States of America
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23
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Eulitz J, G C Troost E, Klünder L, Raschke F, Hahn C, Schulz E, Seidlitz A, Thiem J, Karpowitz C, Hahlbohm P, Grey A, Engellandt K, Löck S, Krause M, Lühr A. Increased relative biological effectiveness and periventricular radiosensitivity in proton therapy of glioma patients. Radiother Oncol 2023; 178:109422. [PMID: 36435337 DOI: 10.1016/j.radonc.2022.11.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 10/25/2022] [Accepted: 11/17/2022] [Indexed: 11/24/2022]
Abstract
PURPOSE Currently, there is an intense debate on variations in intra-cerebral radiosensitivity and relative biological effectiveness (RBE) in proton therapy of primary brain tumours. Here, both effects were retrospectively investigated using late radiation-induced brain injuries (RIBI) observed in follow-up after proton therapy of patients with diagnosed glioma. METHODS In total, 42 WHO grade 2-3 glioma patients out of a consecutive patient cohort having received (adjuvant) proton radio(chemo)therapy between 2014 and 2017 were eligible for analysis. RIBI lesions (symptomatic or clinically asymptomatic) were diagnosed and delineated on contrast-enhanced T1-weighted magnetic resonance imaging scans obtained in the first two years of follow-up. Correlation of RIBI location and occurrence with dose (D), proton dose-averaged linear energy transfer (LET) and variable RBE dose parameters were tested in voxel- and in patient-wise logistic regression analyses. Additionally, anatomical and clinical parameters were considered. Model performance was estimated through cross-validated area-under-the-curve (AUC) values. RESULTS In total, 64 RIBI lesions were diagnosed in 21 patients. The median time between start of proton radio(chemo)therapy and RIBI appearance was 10.2 months. Median distances of the RIBI volume centres to the cerebral ventricles and to the clinical target volume border were 2.1 mm and 1.3 mm, respectively. In voxel-wise regression, the multivariable model with D, D × LET and periventricular region (PVR) revealed the highest AUC of 0.90 (95 % confidence interval: 0.89-0.91) while the corresponding model without D × LET revealed a value of 0.84 (0.83-0.86). In patient-level analysis, the equivalent uniform dose (EUD11, a = 11) in the PVR using a variable RBE was the most prominent predictor for RIBI with an AUC of 0.63 (0.32-0.90). CONCLUSIONS In this glioma cohort, an increased radiosensitivity within the PVR was observed as well as a spatial correlation of RIBI with an increased RBE. Both need to be considered when delivering radio(chemo)therapy using proton beams.
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Affiliation(s)
- Jan Eulitz
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
| | - Esther G C Troost
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; National Center for Tumour Diseases (NCT), Partner Site Dresden, Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, and; Helmholtz Association / Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Dresden, Germany; German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Lauritz Klünder
- Department of Physics, TU Dortmund University, Dortmund, Germany
| | - Felix Raschke
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
| | - Christian Hahn
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; Department of Physics, TU Dortmund University, Dortmund, Germany
| | - Erik Schulz
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Annekatrin Seidlitz
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; National Center for Tumour Diseases (NCT), Partner Site Dresden, Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, and; Helmholtz Association / Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Dresden, Germany; German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Justus Thiem
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; National Center for Tumour Diseases (NCT), Partner Site Dresden, Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, and; Helmholtz Association / Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Dresden, Germany; German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Caroline Karpowitz
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; National Center for Tumour Diseases (NCT), Partner Site Dresden, Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, and; Helmholtz Association / Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Dresden, Germany; German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Patricia Hahlbohm
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Institute and Polyclinic for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Arne Grey
- National Center for Tumour Diseases (NCT), Partner Site Dresden, Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, and; Helmholtz Association / Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Dresden, Germany; German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany; Institute and Polyclinic for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Kay Engellandt
- National Center for Tumour Diseases (NCT), Partner Site Dresden, Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, and; Helmholtz Association / Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Dresden, Germany; German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany; Institute and Polyclinic for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Steffen Löck
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; National Center for Tumour Diseases (NCT), Partner Site Dresden, Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, and; Helmholtz Association / Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Dresden, Germany; German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Mechthild Krause
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; National Center for Tumour Diseases (NCT), Partner Site Dresden, Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, and; Helmholtz Association / Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Dresden, Germany; German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Armin Lühr
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; Department of Physics, TU Dortmund University, Dortmund, Germany.
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24
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Chen M, Cao W, Yepes P, Guan F, Poenisch F, Xu C, Chen J, Li Y, Vazquez I, Yang M, Zhu XR, Zhang X. Impact of dose calculation accuracy on inverse linear energy transfer optimization for intensity‐modulated proton therapy. PRECISION RADIATION ONCOLOGY 2022. [DOI: 10.1002/pro6.1179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Mei Chen
- Department of Radiation Oncology Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
- Department of Radiation Physics The University of Texas MD Anderson Cancer Center Houston Texas USA
| | - Wenhua Cao
- Department of Radiation Physics The University of Texas MD Anderson Cancer Center Houston Texas USA
| | - Pablo Yepes
- Department of Radiation Physics The University of Texas MD Anderson Cancer Center Houston Texas USA
- Physics and Astronomy Department Rice University Houston Texas USA
| | - Fada Guan
- Department of Radiation Physics The University of Texas MD Anderson Cancer Center Houston Texas USA
| | - Falk Poenisch
- Department of Radiation Physics The University of Texas MD Anderson Cancer Center Houston Texas USA
| | - Cheng Xu
- Department of Radiation Oncology Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Jiayi Chen
- Department of Radiation Oncology Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Yupeng Li
- Department of Radiation Physics The University of Texas MD Anderson Cancer Center Houston Texas USA
| | - Ivan Vazquez
- Department of Radiation Physics The University of Texas MD Anderson Cancer Center Houston Texas USA
| | - Ming Yang
- Department of Radiation Physics The University of Texas MD Anderson Cancer Center Houston Texas USA
| | - X. Ronald Zhu
- Department of Radiation Physics The University of Texas MD Anderson Cancer Center Houston Texas USA
| | - Xiaodong Zhang
- Department of Radiation Physics The University of Texas MD Anderson Cancer Center Houston Texas USA
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25
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Yang Y, Rwigema JCM, Vargas C, Yu NY, Keole SR, Wong WW, Schild SE, Bues M, Liu W, Shen J. Technical note: Investigation of dose and LET d effect to rectum and bladder by using non-straight laterals in prostate cancer receiving proton therapy. Med Phys 2022; 49:7428-7437. [PMID: 36208196 DOI: 10.1002/mp.16008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 09/02/2022] [Accepted: 09/22/2022] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Parallel-opposed lateral beams are the conventional beam arrangements in proton therapy for prostate cancer. However, when considering linear energy transfer (LET) and RBE effects, alternative beam arrangements should be investigated. PURPOSE To investigate the dose and dose averaged LET (LETd ) impact of using new beam arrangements rotating beams 5°-15° posteriorly to the laterals in prostate cancer treated with pencil-beam-scanning (PBS) proton therapy. METHODS Twenty patients with localized prostate cancer were included in this study. Four proton treatment plans for each patient were generated utilizing 0°, 5°, 10°, and 15° posterior oblique beam pairs relative to parallel-opposed lateral beams. Dose-volume histograms (DVHs) from posterior oblique beams were analyzed. Dose-LETd -volume histogram (DLVH) was employed to study the difference in dose and LETd with each beam arrangement. DLVH indices, V ( d , l ) $V( {d,l} )$ , defined as the cumulative absolute volume that has a dose of at least d (Gy[RBE]) and a LETd of at least l (keV/µm), were calculated for both the rectum and bladder to the whole group of patients and two-sub groups with and without hydrogel spacer. These metrics were tested using Wilcoxon signed-rank test. RESULTS Rotating beam angles from laterals to slightly posterior by 5°-15° reduced high LETd volumes while it increased the dose volume in the rectum and increased LETd in bladders. Beam angles rotated five degrees posteriorly from laterals (i.e., gantry in 95° and 265°) are proposed since they achieved the optimal balance of better LETd sparing and minimal dose increase in the rectum. A reduction of V(50 Gy[RBE], 2.6 keV/µm) from 7.41 to 3.96 cc (p < 0.01), and a slight increase of V(50 Gy[RBE], 0 keV/µm) from 20.1 to 21.6 cc (p < 0.01) were observed for the group without hydrogel spacer. The LETd sparing was less effective for the group with hydrogel spacer, which achieved the reduction of V(50 Gy[RBE], 2.6 keV/µm) from 4.28 to 2.10 cc (p < 0.01). CONCLUSIONS Posterior oblique angle plans improved LETd sparing of the rectum while sacrificing LETd sparing in the bladder in the treatment of prostate cancer with PBS. Beam angle modification from laterals to slightly posterior may be a strategy to redistribute LETd and perhaps reduce rectal toxicity risks in prostate cancer patients treated with PBS. However, the effect is reduced for patients with hydrogel spacer.
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Affiliation(s)
- Yunze Yang
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | | | - Carlos Vargas
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | - Nathan Y Yu
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | - Sameer R Keole
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | - William W Wong
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | - Steven E Schild
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | - Martin Bues
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | - Wei Liu
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | - Jiajian Shen
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
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Pirlepesov F, Wilson L, Moskvin VP, Breuer A, Parkins F, Lucas JT, Merchant TE, Faught AM. Three-dimensional dose and LET D prediction in proton therapy using artificial neural networks. Med Phys 2022; 49:7417-7427. [PMID: 36227617 PMCID: PMC9872814 DOI: 10.1002/mp.16043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 08/30/2022] [Accepted: 09/21/2022] [Indexed: 01/26/2023] Open
Abstract
PURPOSE Challenges in proton therapy include identifying patients most likely to benefit; ensuring consistent, high-quality plans as its adoption becomes more widespread; and recognizing biological uncertainties that may be related to increased relative biologic effectiveness driven by linear energy transfer (LET). Knowledge-based planning (KBP) is a domain that may help to address all three. METHODS Artificial neural networks were trained using 117 unique treatment plans and associated dose and dose-weighted LET (LETD ) distributions. The data set was split into training (n = 82), validation (n = 17), and test (n = 18) sets. Model performance was evaluated on the test set using dose- and LETD -volume metrics in the clinical target volume (CTV) and nearby organs at risk and Dice similarity coefficients (DSC) comparing predicted and planned isodose lines at 50%, 75%, and 95% of the prescription dose. RESULTS Dose-volume metrics significantly differed (α = 0.05) between predicted and planned dose distributions in only one dose-volume metric, D2% to the CTV. The maximum observed root mean square (RMS) difference between corresponding metrics was 4.3 GyRBE (8% of prescription) for D1cc to optic chiasm. DSC were 0.90, 0.93, and 0.88 for the 50%, 75%, and 95% isodose lines, respectively. LETD -volume metrics significantly differed in all but one metric, L0.1cc of the brainstem. The maximum observed difference in RMS differences for LETD metrics was 1.0 keV/μm for L0.1cc to brainstem. CONCLUSIONS We have devised the first three-dimensional dose and LETD -prediction model for cranial proton radiation therapy has been developed. Dose accuracy compared favorably with that of previously published models in other treatment sites. The agreement in LETD supports future investigations with biological doses in mind to enable the full potential of KBP in proton therapy.
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Affiliation(s)
- Fakhriddin Pirlepesov
- Department of Radiation Oncology, St. Jude
Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN,
38105-3678
| | - Lydia Wilson
- Department of Radiation Oncology, St. Jude
Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN,
38105-3678
| | - Vadim P. Moskvin
- Department of Radiation Oncology, St. Jude
Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN,
38105-3678
| | - Alex Breuer
- Department of Pathology, St. Jude Children’s
Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-3678
| | - Franz Parkins
- Department of Information Services, St. Jude
Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN,
38105-3678
| | - John T. Lucas
- Department of Radiation Oncology, St. Jude
Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN,
38105-3678
| | - Thomas E. Merchant
- Department of Radiation Oncology, St. Jude
Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN,
38105-3678
| | - Austin M. Faught
- Department of Radiation Oncology, St. Jude
Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN,
38105-3678
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Vaniqui A, Vaassen F, Di Perri D, Eekers D, Compter I, Rinaldi I, van Elmpt W, Unipan M. Linear Energy Transfer and Relative Biological Effectiveness Investigation of Various Structures for a Cohort of Proton Patients With Brain Tumors. Adv Radiat Oncol 2022; 8:101128. [PMID: 36632089 PMCID: PMC9827037 DOI: 10.1016/j.adro.2022.101128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 10/31/2022] [Indexed: 11/27/2022] Open
Abstract
Purpose The current knowledge on biological effects associated with proton therapy is limited. Therefore, we investigated the distributions of dose, dose-averaged linear energy transfer (LETd), and the product between dose and LETd (DLETd) for a patient cohort treated with proton therapy. Different treatment planning system features and visualization tools were explored. Methods and Materials For a cohort of 24 patients with brain tumors, the LETd, DLETd, and dose was calculated for a fixed relative biological effectiveness value and 2 variable models: plan-based and phenomenological. Dose threshold levels of 0, 5, and 20 Gy were imposed for LETd visualization. The relationship between physical dose and LETd and the frequency of LETd hotspots were investigated. Results The phenomenological relative biological effectiveness model presented consistently higher dose values. For lower dose thresholds, the LETd distribution was steered toward higher values related to low treatment doses. Differences up to 26.0% were found according to the threshold. Maximum LETd values were identified in the brain, periventricular space, and ventricles. An inverse relationship between LETd and dose was observed. Frequency information to the domain of dose and LETd allowed for the identification of clusters, which steer the mean LETd values, and the identification of higher, but sparse, LETd values. Conclusions Identifying, quantifying, and recording LET distributions in a standardized fashion is necessary, because concern exists over a link between toxicity and LET hotspots. Visualizing DLETd or dose × LETd during treatment planning could allow for clinicians to make informed decisions.
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Faught AM, Wilson LJ, Gargone M, Pirlepesov F, Moskvin VP, Hua C. Treatment-planning approaches to intensity modulated proton therapy and the impact on dose-weighted linear energy transfer. J Appl Clin Med Phys 2022; 24:e13782. [PMID: 36161765 PMCID: PMC9859995 DOI: 10.1002/acm2.13782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 07/13/2022] [Accepted: 08/16/2022] [Indexed: 01/26/2023] Open
Abstract
PURPOSE We quantified the effect of various forward-based treatment-planning strategies in proton therapy on dose-weighted linear energy transfer (LETd). By maintaining the dosimetric quality at a clinically acceptable level, we aimed to evaluate the differences in LETd among various treatment-planning approaches and their practicality in minimizing biologic uncertainties associated with LETd. METHOD Eight treatment-planning strategies that are achievable in commercial treatment-planning systems were applied on a cylindrical water phantom and four pediatric brain tumor cases. Each planning strategy was compared to either an opposed lateral plan (phantom study) or original clinical plan (patient study). Deviations in mean and maximum LETd from clinically acceptable dose distributions were compared. RESULTS In the phantom study, using a range shifter and altering the robust scenarios during optimization had the largest effect on the mean clinical target volume LETd, which was reduced from 4.5 to 3.9 keV/μm in both cases. Variations in the intersection angle between beams had the largest effect on LETd in a ring defined 3 to 5 mm outside the target. When beam intersection angles were reduced from opposed laterals (180°) to 120°, 90°, and 60°, corresponding maximum LETd increased from 7.9 to 8.9, 10.9, and 12.2 keV/μm, respectively. A clear trend in mean and maximum LETd variations in the clinical cases could not be established, though spatial distribution of LETd suggested a strong dependence on patient anatomy and treatment geometry. CONCLUSION Changes in LETd from treatment-plan setup follow intuitive trends in a controlled phantom experiment. Anatomical and other patient-specific considerations, however, can preclude generalizable strategies in clinical cases. For pediatric cranial radiation therapy, we recommend using opposed lateral treatment fields to treat midline targets.
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Affiliation(s)
- Austin M. Faught
- Department of Radiation OncologySt. Jude Children's Research HospitalMemphisTennesseeUSA
| | - Lydia J. Wilson
- Department of Radiation OncologySt. Jude Children's Research HospitalMemphisTennesseeUSA
| | - Melissa Gargone
- Department of Radiation OncologySt. Jude Children's Research HospitalMemphisTennesseeUSA
| | - Fakhriddin Pirlepesov
- Department of Radiation OncologySt. Jude Children's Research HospitalMemphisTennesseeUSA
| | - Vadim P. Moskvin
- Department of Radiation OncologySt. Jude Children's Research HospitalMemphisTennesseeUSA
| | - Chia‐Ho Hua
- Department of Radiation OncologySt. Jude Children's Research HospitalMemphisTennesseeUSA
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Lee H, Shin J, Verburg JM, Bobić M, Winey B, Schuemann J, Paganetti H. MOQUI: an open-source GPU-based Monte Carlo code for proton dose calculation with efficient data structure. Phys Med Biol 2022; 67:10.1088/1361-6560/ac8716. [PMID: 35926482 PMCID: PMC9513828 DOI: 10.1088/1361-6560/ac8716] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 08/04/2022] [Indexed: 11/11/2022]
Abstract
Objective.Monte Carlo (MC) codes are increasingly used for accurate radiotherapy dose calculation. In proton therapy, the accuracy of the dose calculation algorithm is expected to have a more significant impact than in photon therapy due to the depth-dose characteristics of proton beams. However, MC simulations come at a considerable computational cost to achieve statistically sufficient accuracy. There have been efforts to improve computational efficiency while maintaining sufficient accuracy. Among those, parallelizing particle transportation using graphic processing units (GPU) achieved significant improvements. Contrary to the central processing unit, a GPU has limited memory capacity and is not expandable. It is therefore challenging to score quantities with large dimensions requiring extensive memory. The objective of this study is to develop an open-source GPU-based MC package capable of scoring those quantities.Approach.We employed a hash-table, one of the key-value pair data structures, to efficiently utilize the limited memory of the GPU and score the quantities requiring a large amount of memory. With the hash table, only voxels interacting with particles will occupy memory, and we can search the data efficiently to determine their address. The hash-table was integrated with a novel GPU-based MC code, moqui.Main results.The developed code was validated against an MC code widely used in proton therapy, TOPAS, with homogeneous and heterogeneous phantoms. We also compared the dose calculation results of clinical treatment plans. The developed code agreed with TOPAS within 2%, except for the fall-off and regions, and the gamma pass rates of the results were >99% for all cases with a 2 mm/2% criteria.Significance.We can score dose-influence matrix and dose-rate on a GPU for a 3-field H&N case with 10 GB of memory using moqui, which would require more than 100 GB of memory with the conventionally used array data structure.
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Affiliation(s)
- Hoyeon Lee
- Dept. of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
| | - Jungwook Shin
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD 20850, United States of America
| | - Joost M Verburg
- Dept. of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
| | - Mislav Bobić
- Dept. of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
- Department of Physics, ETH, Zürich 8092, Switzerland
| | - Brian Winey
- Dept. of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
| | - Jan Schuemann
- Dept. of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
| | - Harald Paganetti
- Dept. of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
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Mairani A, Mein S, Blakely E, Debus J, Durante M, Ferrari A, Fuchs H, Georg D, Grosshans DR, Guan F, Haberer T, Harrabi S, Horst F, Inaniwa T, Karger CP, Mohan R, Paganetti H, Parodi K, Sala P, Schuy C, Tessonnier T, Titt U, Weber U. Roadmap: helium ion therapy. Phys Med Biol 2022; 67. [PMID: 35395649 DOI: 10.1088/1361-6560/ac65d3] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 04/08/2022] [Indexed: 12/16/2022]
Abstract
Helium ion beam therapy for the treatment of cancer was one of several developed and studied particle treatments in the 1950s, leading to clinical trials beginning in 1975 at the Lawrence Berkeley National Laboratory. The trial shutdown was followed by decades of research and clinical silence on the topic while proton and carbon ion therapy made debuts at research facilities and academic hospitals worldwide. The lack of progression in understanding the principle facets of helium ion beam therapy in terms of physics, biological and clinical findings persists today, mainly attributable to its highly limited availability. Despite this major setback, there is an increasing focus on evaluating and establishing clinical and research programs using helium ion beams, with both therapy and imaging initiatives to supplement the clinical palette of radiotherapy in the treatment of aggressive disease and sensitive clinical cases. Moreover, due its intermediate physical and radio-biological properties between proton and carbon ion beams, helium ions may provide a streamlined economic steppingstone towards an era of widespread use of different particle species in light and heavy ion therapy. With respect to the clinical proton beams, helium ions exhibit superior physical properties such as reduced lateral scattering and range straggling with higher relative biological effectiveness (RBE) and dose-weighted linear energy transfer (LETd) ranging from ∼4 keVμm-1to ∼40 keVμm-1. In the frame of heavy ion therapy using carbon, oxygen or neon ions, where LETdincreases beyond 100 keVμm-1, helium ions exhibit similar physical attributes such as a sharp lateral penumbra, however, with reduced radio-biological uncertainties and without potentially spoiling dose distributions due to excess fragmentation of heavier ion beams, particularly for higher penetration depths. This roadmap presents an overview of the current state-of-the-art and future directions of helium ion therapy: understanding physics and improving modeling, understanding biology and improving modeling, imaging techniques using helium ions and refining and establishing clinical approaches and aims from learned experience with protons. These topics are organized and presented into three main sections, outlining current and future tasks in establishing clinical and research programs using helium ion beams-A. Physics B. Biological and C. Clinical Perspectives.
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Affiliation(s)
- Andrea Mairani
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany.,National Centre of Oncological Hadrontherapy (CNAO), Medical Physics, Pavia, Italy.,Division of Molecular and Translational Radiation Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, 69120 Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Stewart Mein
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany.,Division of Molecular and Translational Radiation Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, 69120 Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany.,German Cancer Consortium (DKTK) Core-Center Heidelberg, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Eleanor Blakely
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America
| | - Jürgen Debus
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany.,Division of Molecular and Translational Radiation Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, 69120 Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany.,German Cancer Consortium (DKTK) Core-Center Heidelberg, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Clinical Cooperation Unit Radiation Oncology, Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg University and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Marco Durante
- GSI Helmholtzzentrum für Schwerionenforschung, D-64291 Darmstadt, Germany.,Technische Universität Darmstadt, Institut für Physik Kondensierter Materie, Darmstadt, Germany
| | - Alfredo Ferrari
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Hermann Fuchs
- Division of Medical Physics, Department of Radiation Oncology, Medical University of Vienna, Austria.,MedAustron Ion Therapy Center, Wiener Neustadt, Austria
| | - Dietmar Georg
- Division of Medical Physics, Department of Radiation Oncology, Medical University of Vienna, Austria.,MedAustron Ion Therapy Center, Wiener Neustadt, Austria
| | - David R Grosshans
- The University of Texas MD Anderson cancer Center, Houston, Texas, United States of America
| | - Fada Guan
- The University of Texas MD Anderson cancer Center, Houston, Texas, United States of America.,Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, 06510, United States of America
| | - Thomas Haberer
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Semi Harrabi
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany.,German Cancer Consortium (DKTK) Core-Center Heidelberg, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Clinical Cooperation Unit Radiation Oncology, Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg University and German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Tumor Diseases (NCT), Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Felix Horst
- GSI Helmholtzzentrum für Schwerionenforschung, D-64291 Darmstadt, Germany
| | - Taku Inaniwa
- Department of Accelerator and Medical Physics, Institute for Quantum Medical Science, QST, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.,Medical Physics Laboratory, Division of Health Science, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Christian P Karger
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany.,Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Radhe Mohan
- The University of Texas MD Anderson cancer Center, Houston, Texas, United States of America
| | - Harald Paganetti
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, United States of America.,Harvard Medical School, Boston, United States of America
| | - Katia Parodi
- Ludwig-Maximilians-Universität München, Department of Experimental Physics-Medical Physics, Munich, Germany
| | - Paola Sala
- Ludwig-Maximilians-Universität München, Department of Experimental Physics-Medical Physics, Munich, Germany
| | - Christoph Schuy
- GSI Helmholtzzentrum für Schwerionenforschung, D-64291 Darmstadt, Germany
| | - Thomas Tessonnier
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Uwe Titt
- The University of Texas MD Anderson cancer Center, Houston, Texas, United States of America
| | - Ulrich Weber
- GSI Helmholtzzentrum für Schwerionenforschung, D-64291 Darmstadt, Germany
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Yang Y, Patel SH, Bridhikitti J, Wong WW, Halyard MY, McGee LA, Rwigema JCM, Schild SE, Vora SA, Liu T, Bues M, Fatyga M, Foote RL, Liu W. Exploratory study of seed spots analysis to characterize dose and linear energy transfer effect in adverse event initialization of pencil beam scanning proton therapy. Med Phys 2022; 49:6237-6252. [PMID: 35820062 DOI: 10.1002/mp.15859] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 06/20/2022] [Accepted: 07/06/2022] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Both dose and linear-energy-transfer (LET) could play a substantial role in adverse event (AE) initialization of cancer patients treated with pencil-beam-scanning proton therapy (PBS). However, not all the voxels within the AE regions are directly induced from the dose and LET effect. It is important to study the synergistic effect of dose and LET in AE initialization by only including a subset of voxels that are dosimetrically important. PURPOSE To perform exploratory investigation of the dose and LET effects upon AE initialization in PBS using seed spots analysis. METHODS 113 head and neck (H&N) cancer patients receiving curative PBS were included. Among them, 20 patients experienced unanticipated CTCAEv4.0 grade≥3 AEs (AE group) and 93 patients did not (control group). Within the AE group, 13 AE patients were included in the seed spot analysis to derive the descriptive features of AE initialization and the remaining 7 mandible osteoradionecrosis patients and 93 control patients were used to derive the feature-based volume constraint of mandible osteoradionecrosis. The AE regions were contoured and the corresponding dose-LET volume histograms (DLVHs) of AE regions were generated for all patients in the AE group. We selected high LET voxels (the highest 5% of each dose bin) with a range of moderate to high dose (≥∼40 Gy[RBE]) as critical voxels. Critical voxels which were contiguous with each other were grouped into clusters. Each cluster was considered as a potential independent seed spot for AE initialization. Seed spots were displayed in a 2D dose-LET plane based on their mean dose and LET to derive the descriptive features of AE initialization. A volume constraint of mandible osteoradionecrosis was then established based on the extracted features using a receiver operating characteristic curve. RESULTS The product of dose and LET (xBD) was found to be a descriptive feature of seed spots leading to AE initialization in this preliminary study. The derived xBD volume constraint for mandible osteoradionecrosis showed good performance with an area-under-curve of 0.87 (sensitivity of 0.714 and specificity of 0.807 in the leave-one-out cross validation) for the very limited patient data included in this study. CONCLUSION Our exploratory study showed that both dose and LET were observed to be important in AE initializations. The derived xBD volume constraint could predict mandible osteoradionecrosis reasonably well in the very limited H&N cancer patient data treated with PBS included in this study. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Yunze Yang
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | - Samir H Patel
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | - Jidapa Bridhikitti
- Department of Radiation Oncology, Mayo Clinic Rochester, Rochester, Minnesota, USA
| | - William W Wong
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | - Michele Y Halyard
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | - Lisa A McGee
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | | | - Steven E Schild
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | - Sujay A Vora
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | - Tianming Liu
- Department of Computer Science, the University of Georgia, Athens, Georgia, USA
| | - Martin Bues
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | - Mirek Fatyga
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | - Robert L Foote
- Department of Radiation Oncology, Mayo Clinic Rochester, Rochester, Minnesota, USA
| | - Wei Liu
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona, USA
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Cao W, Rocha H, Mohan R, Lim G, Goudarzi HM, Ferreira BC, Dias JM. Reflections on beam configuration optimization for intensity-modulated proton therapy. Phys Med Biol 2022; 67. [PMID: 35561700 DOI: 10.1088/1361-6560/ac6fac] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 05/13/2022] [Indexed: 11/11/2022]
Abstract
Abstract
Presumably, intensity-modulated proton radiotherapy (IMPT) is the most powerful form of proton radiotherapy. In the current state of the art, IMPT beam configurations (i.e. the number of beams and their directions) are, in general, chosen subjectively based on prior experience and practicality. Beam configuration optimization (BCO) for IMPT could, in theory, significantly enhance IMPT’s therapeutic potential. However, BCO is complex and highly computer resource-intensive. Some algorithms for BCO have been developed for intensity-modulated photon therapy (IMRT). They are rarely used clinically mainly because the large number of beams typically employed in IMRT renders BCO essentially unnecessary. Moreover, in the newer form of IMRT, volumetric modulated arc therapy, there are no individual static beams. BCO is of greater importance for IMPT because it typically employs a very small number of beams (2-4) and, when the number of beams is small, BCO is critical for improving plan quality. However, the unique properties and requirements of protons, particularly in IMPT, make BCO challenging. Protons are more sensitive than photons to anatomic changes, exhibit variable relative biological effectiveness along their paths, and, as recently discovered, may spare the immune system. Such factors must be considered in IMPT BCO, though doing so would make BCO more resource intensive and make it more challenging to extend BCO algorithms developed for IMRT to IMPT. A limited amount of research in IMPT BCO has been conducted; however, considerable additional work is needed for its further development to make it truly effective and computationally practical. This article aims to provide a review of existing BCO algorithms, most of which were developed for IMRT, and addresses important requirements specific to BCO for IMPT optimization that necessitate the modification of existing approaches or the development of new effective and efficient ones.
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Heuchel L, Hahn C, Pawelke J, Sørensen BS, Dosanjh M, Lühr A. Clinical use and future requirements of relative biological effectiveness: survey among all european proton therapy centres. Radiother Oncol 2022; 172:134-139. [PMID: 35605747 DOI: 10.1016/j.radonc.2022.05.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/29/2022] [Accepted: 05/15/2022] [Indexed: 01/10/2023]
Abstract
BACKGROUND AND PURPOSE The relative biological effectiveness (RBE) varies along the treatment field. However, in clinical practice, a constant RBE of 1.1 is assumed, which can result in undesirable side effects. This study provides an accurate overview of current clinical practice for considering proton RBE in Europe. MATERIALS AND METHODS A survey was devised and sent to all proton therapy centres in Europe that treat patients. The online questionnaire consisted of 39 questions addressing various aspects of RBE consideration in clinical practice, including treatment planning, patient follow-up and future demands. RESULTS All 25 proton therapy centres responded. All centres prescribed a constant RBE of 1.1, but also applied measures (except for one eye treatment centre) to counteract variable RBE effects such as avoiding beams stopping inside or in front of an organ at risk and putting restrictions on the minimum number and opening angle of incident beams for certain treatment sites. For the future, most centres (16) asked for more retrospective or prospective outcome studies investigating the potential effect of the effect of a variable RBE. To perform such studies, 18 centres asked for LET and RBE calculation and visualisation tools developed by treatment planning system vendors. CONCLUSION All European proton centres are aware of RBE variability but comply with current guidelines of prescribing a constant RBE. However, they actively mitigate uncertainty and risk of side effects resulting from increased RBE by applying measures and restrictions during treatment planning. To change RBE-related clinical guidelines in the future more clinical data on RBE are explicitly demanded.
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Affiliation(s)
- Lena Heuchel
- Department of Physics, TU Dortmund University, Germany
| | - Christian Hahn
- Department of Physics, TU Dortmund University, Germany; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany
| | - Jörg Pawelke
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Germany; Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Germany
| | - Brita Singers Sørensen
- Department of Experimental Clinical Oncology, Aarhus University Hospital, Denmark; Danish Center for Particle Therapy, DCPT, Aarhus University Hospital, Denmark
| | - Manjit Dosanjh
- Department of Physics, University of Oxford, UK; CERN, Geneva, Switzerland
| | - Armin Lühr
- Department of Physics, TU Dortmund University, Germany.
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Qi Y, Mao L, Lu H, Jin S, Huang J, Wang Z, Zhang J, Wang K. Multi-centric analysis of linear energy transfer distribution from clinical proton beam based on TOPAS. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Biological Dose Optimization for Particle Arc Therapy using Helium and Carbon Ions. Int J Radiat Oncol Biol Phys 2022; 114:334-348. [PMID: 35490991 DOI: 10.1016/j.ijrobp.2022.04.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 04/11/2022] [Accepted: 04/19/2022] [Indexed: 11/22/2022]
Abstract
PURPOSE To present biological dose optimization for particle arc therapy using helium and carbon ions. METHODS Treatment plan planning and optimization procedures were developed for spot-scanning hadron arc (SHArc) delivery using the RayStation TPS and a GPU-accelerated dose engine (†TPS-XXX). The SHArc optimization algorithm is applicable for charged particle beams and determines angle-dependencies for spot/energy selection with three main initiatives: i) achieve standard clinical optimization goals and constraints for target and OARs, ii) target dose robustness and iii) increasing LET in the target volume. Three patient cases previously treated at the †INSTITUTION-XXX were selected for evaluation of conventional versus arc delivery for the two clinical particle beams (helium [4He] and carbon [12C] ions): glioblastoma, prostate-adenocarcinoma and skull-base chordoma. Biological dose and dose-averaged linear energy transfer (LETd) distributions for SHArc were evaluated against conventional planning techniques (VMAT and IMPT2F) applying the modified microdosimetric kinetic model (mMKM) for considering bio-effect with (α/β)x=2Gy. Clinical viability and deliverability were assessed via evaluation of plan quality, robustness and irradiation time. RESULTS For all investigated patient cases, SHArc treatment optimizations met planning goals and constraints for target coverage and OARs, exhibiting acceptable target coverage and reduced normal tissue volumes with effective dose >10GyRBE compared to conventional 2F planning. For carbon ions, LETd was increased in the target volume from ∼40-60keV/µm to ∼80-140keV/µm for SHArc compared to conventional treatments. Favorable LETd distributions were possible with the SHArc approach, with maximum LETd in CTV/GTV and potential reductions of high-LET regions in normal tissues and OARs. Compared to VMAT, SHArc affords substantial reductions in normal tissue dose (40-70%). CONCLUSION SHArc therapy offers potential treatment benefits such as increased normal tissue sparing from higher doses >10GyRBE, enhanced target LETd, and potential reduction in high-LET components in OARs. Findings justify further development of robust SHArc treatment planning towards potential clinical translation.
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Mohan R. A review of proton therapy – Current status and future directions. PRECISION RADIATION ONCOLOGY 2022; 6:164-176. [DOI: 10.1002/pro6.1149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Radhe Mohan
- Department of Radiation Physics, MD Anderson Cancer Center Houston Texas USA
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Yang Y, Muller OM, Shiraishi S, Harper M, Amundson AC, Wong WW, McGee LA, Rwigema JCM, Schild SE, Bues M, Fatyga M, Anderson JD, Patel SH, Foote RL, Liu W. Empirical Relative Biological Effectiveness (RBE) for Mandible Osteoradionecrosis (ORN) in Head and Neck Cancer Patients Treated With Pencil-Beam-Scanning Proton Therapy (PBSPT): A Retrospective, Case-Matched Cohort Study. Front Oncol 2022; 12:843175. [PMID: 35311159 PMCID: PMC8928456 DOI: 10.3389/fonc.2022.843175] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose To retrospectively investigate empirical relative biological effectiveness (RBE) for mandible osteoradionecrosis (ORN) in head and neck (H&N) cancer patients treated with pencil-beam-scanning proton therapy (PBSPT). Methods We included 1,266 H&N cancer patients, of which, 931 patients were treated with volumetric-modulated arc therapy (VMAT) and 335 were treated with PBSPT. Among them, 26 VMAT and 9 PBSPT patients experienced mandible ORN (ORN group), while all others were included in the control group. To minimize the impact of the possible imbalance in clinical factors between VMAT and PBSPT patients in the dosimetric comparison between these two modalities and the resulting RBE quantification, we formed a 1:1 case-matched patient cohort (335 VMAT patients and 335 PBSPT patients including both the ORN and control groups) using the greedy nearest neighbor matching of propensity scores. Mandible dosimetric metrics were extracted from the case-matched patient cohort and statistically tested to evaluate the association with mandibular ORN to derive dose volume constraints (DVCs) for VMAT and PBSPT, respectively. We sought the equivalent constraint doses for VMAT so that the critical volumes of VMAT were equal to those of PBSPT at different physical doses. Empirical RBEs of PBSPT for ORN were obtained by calculating the ratio between the derived equivalent constraint doses and physical doses of PBSPT. Bootstrapping was further used to get the confidence intervals. Results Clinical variables of age, gender, tumor stage, prescription dose, chemotherapy, hypertension or diabetes, dental extraction, smoking history, or current smoker were not statistically related to the incidence of ORN in the overall patient cohort. Smoking history was found to be significantly associated with the ORN incidence in PBSPT patients only. V40Gy[RBE], V50Gy[RBE], and V60Gy[RBE] were statistically different (p<0.05) between the ORN and control group for VMAT and PBSPT. Empirical RBEs of 1.58(95%CI: 1.34-1.64), 1.34(95%CI: 1.23-1.40), and 1.24(95%: 1.15-1.26) were obtained for proton dose at 40 Gy[RBE=1.1], 50 Gy[RBE=1.1] and 60 Gy[RBE=1.1], respectively. Conclusions Our study suggested that RBEs were larger than 1.1 at moderate doses (between 40 and 60 Gy[RBE=1.1]) with high LET for mandible ORN. RBEs are underestimated in current clinical practice in PBSPT. The derived DVCs can be used for PBSPT plan evaluation and optimization to minimize the incidence rate of mandible ORN.
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Affiliation(s)
- Yunze Yang
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, United States
| | - Olivia M Muller
- Department of Dental Specialties, Mayo Clinic Rochester, Rochester, MN, United States
| | - Satomi Shiraishi
- Department of Radiation Oncology, Mayo Clinic Rochester, Rochester, MN, United States
| | - Matthew Harper
- School of Dentistry, West Virginia University, Morgantown, WV, United States
| | - Adam C Amundson
- Department of Radiation Oncology, Mayo Clinic Rochester, Rochester, MN, United States
| | - William W Wong
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, United States
| | - Lisa A McGee
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, United States
| | | | - Steven E Schild
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, United States
| | - Martin Bues
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, United States
| | - Mirek Fatyga
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, United States
| | - Justin D Anderson
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, United States
| | - Samir H Patel
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, United States
| | - Robert L Foote
- Department of Radiation Oncology, Mayo Clinic Rochester, Rochester, MN, United States
| | - Wei Liu
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, United States
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Garbacz M, Gajewski J, Durante M, Kisielewicz K, Krah N, Kopeć R, Olko P, Patera V, Rinaldi I, Rydygier M, Schiavi A, Scifoni E, Skóra T, Skrzypek A, Tommasino F, Rucinski A. Quantification of biological range uncertainties in patients treated at the Krakow proton therapy centre. Radiat Oncol 2022; 17:50. [PMID: 35264184 PMCID: PMC8905899 DOI: 10.1186/s13014-022-02022-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 02/28/2022] [Indexed: 12/02/2022] Open
Abstract
Background Variable relative biological effectiveness (vRBE) in proton therapy might significantly modify the prediction of RBE-weighted dose delivered to a patient during proton therapy. In this study we will present a method to quantify the biological range extension of the proton beam, which results from the application of vRBE approach in RBE-weighted dose calculation. Methods and materials The treatment plans of 95 patients (brain and skull base patients) were used for RBE-weighted dose calculation with constant and the McNamara RBE model. For this purpose the Monte Carlo tool FRED was used. The RBE-weighted dose distributions were analysed using indices from dose-volume histograms. We used the volumes receiving at least 95% of the prescribed dose (V95) to estimate the biological range extension resulting from vRBE approach. Results The vRBE model shows higher median value of relative deposited dose and D95 in the planning target volume by around 1% for brain patients and 4% for skull base patients. The maximum doses in organs at risk calculated with vRBE was up to 14 Gy above dose limit. The mean biological range extension was greater than 0.4 cm. Discussion Our method of estimation of biological range extension is insensitive for dose inhomogeneities and can be easily used for different proton plans with intensity-modulated proton therapy (IMPT) optimization. Using volumes instead of dose profiles, which is the common method, is more universal. However it was tested only for IMPT plans on fields arranged around the tumor area. Conclusions Adopting a vRBE model results in an increase in dose and an extension of the beam range, which is especially disadvantageous in cancers close to organs at risk. Our results support the need to re-optimization of proton treatment plans when considering vRBE.
Supplementary Information The online version contains supplementary material available at 10.1186/s13014-022-02022-5.
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Affiliation(s)
- Magdalena Garbacz
- Institute of Nuclear Physics Polish Academy of Sciences, 31342, Kraków, Poland.
| | - Jan Gajewski
- Institute of Nuclear Physics Polish Academy of Sciences, 31342, Kraków, Poland
| | - Marco Durante
- GSI Helmholtzzentrum fur Schwerionenforschung, 64291, Darmstadt, Germany.,The Technical University of Darmstadt, 64289, Darmstadt, Germany
| | - Kamil Kisielewicz
- National Oncology Institute, National Research Institute, Krakow Branch, 31115, Kraków, Poland
| | - Nils Krah
- University of Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, Centre Léon Bérard, France.,University of Lyon, Université Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822, Villeurbanne, France
| | - Renata Kopeć
- Institute of Nuclear Physics Polish Academy of Sciences, 31342, Kraków, Poland
| | - Paweł Olko
- Institute of Nuclear Physics Polish Academy of Sciences, 31342, Kraków, Poland
| | - Vincenzo Patera
- INFN - Section of Rome, 00185, Rome, Italy.,Department of Basic and Applied Sciences for Engineering, Sapienza University of Rome, 00161, Rome, Italy
| | | | - Marzena Rydygier
- Institute of Nuclear Physics Polish Academy of Sciences, 31342, Kraków, Poland
| | | | - Emanuele Scifoni
- Trento Institute for Fundamental Physics and Applications, TIFPA-INFN, 38123, Povo, Trento, Italy
| | - Tomasz Skóra
- National Oncology Institute, National Research Institute, Krakow Branch, 31115, Kraków, Poland
| | | | - Francesco Tommasino
- Trento Institute for Fundamental Physics and Applications, TIFPA-INFN, 38123, Povo, Trento, Italy.,Department of Physics, University of Trento, 38123, Povo, Trento, Italy
| | - Antoni Rucinski
- Institute of Nuclear Physics Polish Academy of Sciences, 31342, Kraków, Poland
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Koh WYC, Tan HQ, Ng YY, Lin YH, Ang KW, Lew WS, Lee JCL, Park SY. Quantifying Systematic RBE-Weighted Dose Uncertainty Arising from Multiple Variable RBE Models in Organ at Risk. Adv Radiat Oncol 2022; 7:100844. [PMID: 35036633 PMCID: PMC8749202 DOI: 10.1016/j.adro.2021.100844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 09/27/2021] [Accepted: 10/29/2021] [Indexed: 11/22/2022] Open
Abstract
PURPOSE Relative biological effectiveness (RBE) uncertainties have been a concern for treatment planning in proton therapy, particularly for treatment sites that are near organs at risk (OARs). In such a clinical situation, the utilization of variable RBE models is preferred over constant RBE model of 1.1. The problem, however, lies in the exact choice of RBE model, especially when current RBE models are plagued with a host of uncertainties. This paper aims to determine the influence of RBE models on treatment planning, specifically to improve the understanding of the influence of the RBE models with regard to the passing and failing of treatment plans. This can be achieved by studying the RBE-weighted dose uncertainties across RBE models for OARs in cases where the target volume overlaps the OARs. Multi-field optimization (MFO) and single-field optimization (SFO) plans were compared in order to recommend which technique was more effective in eliminating the variations between RBE models. METHODS Fifteen brain tumor patients were selected based on their profile where their target volume overlaps with both the brain stem and the optic chiasm. In this study, 6 RBE models were analyzed to determine the RBE-weighted dose uncertainties. Both MFO and SFO planning techniques were adopted for the treatment planning of each patient. RBE-weighted dose uncertainties in the OARs are calculated assuming( α β ) x of 3 Gy and 8 Gy. Statistical analysis was used to ascertain the differences in RBE-weighted dose uncertainties between MFO and SFO planning. Additionally, further investigation of the linear energy transfer (LET) distribution was conducted to determine the relationship between LET distribution and RBE-weighted dose uncertainties. RESULTS The results showed no strong indication on which planning technique would be the best for achieving treatment planning constraints. MFO and SFO showed significant differences (P <.05) in the RBE-weighted dose uncertainties in the OAR. In both clinical target volume (CTV)-brain stem and CTV-chiasm overlap region, 10 of 15 patients showed a lower median RBE-weighted dose uncertainty in MFO planning compared with SFO planning. In the LET analysis, 8 patients (optic chiasm) and 13 patients (brain stem) showed a lower mean LET in MFO planning compared with SFO planning. It was also observed that lesser RBE-weighted dose uncertainties were present with MFO planning compared with SFO planning technique. CONCLUSIONS Calculations of the RBE-weighted dose uncertainties based on 6 RBE models and 2 different( α β ) x revealed that MFO planning is a better option as opposed to SFO planning for cases of overlapping brain tumor with OARs in eliminating RBE-weighted dose uncertainties. Incorporation of RBE models failed to dictate the passing or failing of a treatment plan. To eliminate RBE-weighted dose uncertainties in OARs, the MFO planning technique is recommended for brain tumor when CTV and OARs overlap.
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Affiliation(s)
- Wei Yang Calvin Koh
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore
- Division of Radiation Oncology, National Cancer Centre Singapore, Singapore
| | - Hong Qi Tan
- Division of Radiation Oncology, National Cancer Centre Singapore, Singapore
| | - Yan Yee Ng
- Division of Radiation Oncology, National Cancer Centre Singapore, Singapore
| | - Yen Hwa Lin
- Division of Radiation Oncology, National Cancer Centre Singapore, Singapore
| | - Khong Wei Ang
- Division of Radiation Oncology, National Cancer Centre Singapore, Singapore
| | - Wen Siang Lew
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore
| | - James Cheow Lei Lee
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore
- Division of Radiation Oncology, National Cancer Centre Singapore, Singapore
| | - Sung Yong Park
- Division of Radiation Oncology, National Cancer Centre Singapore, Singapore
- Oncology Academic Clinical Programme, Duke-NUS Medical School, National University of Singapore, Singapore
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Rana S, Traneus E, Jackson M, Tran L, Rosenfeld AB. Quantitative analysis of dose-averaged linear energy transfer (LET d ) robustness in pencil beam scanning proton lung plans. Med Phys 2022; 49:3444-3456. [PMID: 35194809 DOI: 10.1002/mp.15569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 02/14/2022] [Accepted: 02/14/2022] [Indexed: 11/09/2022] Open
Abstract
PURPOSE The primary objective of our study was to perform a quantitative robustness analysis of the dose-averaged linear energy transfer (LETd ) and related RBE-weighted dose in robustly optimized (in terms of the range and set up uncertainties) pencil beam scanning (PBS) proton lung cancer plans. METHODS In this study, we utilized the 4DCT data set of six anonymized lung patients. PBS lung plans were generated using a robust optimization technique (range uncertainty: ±3.5% and setup errors: ±5 mm) on the CTV for a total dose of 5000 cGy(RBE) in 5 fractions using RBE of 1.1. For each patient, the LETd distributions were calculated for the nominal plan and three groups. Group 1: two plan robustness scenarios for range uncertainties of ±3.5%; Group 2: twelve plan robustness scenarios (range uncertainty (±3.5%) in conjunction with setup errors (±5 mm)); and Group 3: ten different breathing phases of the 4DCT data set. RBE-weighted dose to the OARs was evaluated for all robustness scenarios and breathing phases. The variation (∆) in the mean LETd and mean RBE-weighted dose from each group was recorded. RESULTS The mean LETd in the CTV of nominal PBS lung plans among six patients ranged from 2.2 to 2.6 keV/μm. On average, for the combined range and setup uncertainties, the ∆ in the mean LETd among 12 scenarios of all six patients was 0.6 keV/μm, which is slightly higher than when only the range uncertainties were considered (0.4 keV/μm). The ∆ in the mean LETd in a patient was ≤1.7 keV/μm in the heart and ≤1.2 keV/μm in the esophagus and total lung. The ∆ in the mean RBE-weighted dose in a patient was up to 79 cGy for the total lung, 165 cGy for the heart, and 258 cGy for the esophagus. For ten breathing phases, the ∆ in the mean LETd in a patient was ≤0.3 keV/μm in the CTV, ≤0.5 keV/μm in the heart, ≤0.4 keV/μm in the esophagus, and ≤0.7 keV/μm in the total lung. CONCLUSION The addition of setup errors to the range uncertainties resulted in slightly less homogeneous LETd distributions. The variations in the mean LETd among ten breathing phases were slightly larger in the total lung than in the heart and esophagus. The combination of setup and range uncertainties had a greater impact than the effect of breathing phases on the variations in the mean RBE-weighted dose to the OARs. Overall, the LETd distributions in the CTV were less sensitive than those in the OARs to setup errors, range uncertainties, and breathing phases for robustly optimized PBS proton lung cancer plans. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Suresh Rana
- Department of Radiation Oncology, Lynn Cancer Institute, Boca Raton Regional Hospital, Baptist Health South Florida, Boca Raton, Florida, USA.,Department of Medical Physics, The Oklahoma Proton Center, Oklahoma City, Oklahoma, USA.,Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW, Australia
| | - Erik Traneus
- RaySearch Laboratories, Medical Physics, Stockholm, Sweden
| | - Michael Jackson
- Prince of Wales Hospital, Radiation Oncology, Randwick, Australia
| | - Linh Tran
- Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW, Australia
| | - Anatoly B Rosenfeld
- Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW, Australia
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Upadhyay R, Liao K, Grosshans DR, McGovern SL, Frances McAleer M, Zaky W, Chintagumpala MM, Mahajan A, Nana Yeboa D, Paulino AC. Quantifying the risk and dosimetric variables of symptomatic brainstem injury after proton beam radiation in pediatric brain tumors. Neuro Oncol 2022; 24:1571-1581. [PMID: 35157767 PMCID: PMC9435496 DOI: 10.1093/neuonc/noac044] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Brainstem toxicity after radiation therapy (RT) is a devastating complication and a particular concern with proton radiation (PBT). We investigated the incidence and clinical correlates of brainstem injury in pediatric brain tumors treated with PBT. METHODS All patients <21 years with brain tumors treated with PBT at our institution from 2007-2019, with a brainstem Dmean >30 Gy and/or Dmax >50.4 Gy were included. Symptomatic brainstem injury (SBI) was defined as any new or progressive cranial neuropathy, ataxia, and/or motor weakness with corresponding radiographic abnormality within brainstem. RESULTS A total of 595 patients were reviewed and 468 (medulloblastoma = 200, gliomas = 114, ependymoma = 87, ATRT = 43) met our inclusion criteria. Median age at RT was 6.3 years and median prescribed RT dose was 54Gy [RBE]. Fifteen patients (3.2%) developed SBI, at a median of 4 months after RT. Grades 2, 3, 4, and 5 brainstem injuries were seen in 7, 5, 1, and 2 patients respectively. Asymptomatic radiographic changes were seen in 51 patients (10.9%). SBI was significantly higher in patients with age ≤3 years, female gender, ATRT histology, patients receiving high-dose chemotherapy with stem cell rescue, and those not receiving craniospinal irradiation. Patients with SBI had a significantly higher V50-52. In 2014, our institution started using strict brainstem dose constraints (Dmax ≤57 Gy, Dmean ≤52.4 Gy, and V54≤10%). There was a trend towards decrease in SBI from 4.4% (2007-2013) to 1.5% (2014-2019) (P = .089) without affecting survival. CONCLUSION Our results suggest a low risk of SBI after PBT for pediatric brain tumors, comparable to photon therapy. A lower risk was seen after adopting strict brainstem dose constraints.
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Affiliation(s)
- Rituraj Upadhyay
- Department of Radiation Oncology, The James Cancer Centre Ohio State University, Columbus, Ohio, USA
| | - Kaiping Liao
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - David R Grosshans
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Susan L McGovern
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Mary Frances McAleer
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Wafik Zaky
- Department of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | | | - Anita Mahajan
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, USA
| | - Debra Nana Yeboa
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Arnold C Paulino
- Corresponding Author: Arnold C. Paulino, MD, Department of Radiation Oncology, MD Anderson Cancer Center, 1515 Holcombe Blvd, Unit 0097, Houston, TX 77030, USA ()
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Fujii Y, Ueda H, Umegaki K, Matsuura T. An initial systematic study of the linear energy transfer distributions of a proton beam under a transverse magnetic field. Med Phys 2022; 49:1839-1852. [DOI: 10.1002/mp.15478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 01/11/2022] [Accepted: 01/12/2022] [Indexed: 11/10/2022] Open
Affiliation(s)
- Yusuke Fujii
- Graduate School of Engineering Hokkaido University Sapporo Hokkaido Japan
- Hitachi Ltd. Hitachi Ibaraki Japan
| | - Hideaki Ueda
- Faculty of Engineering Hokkaido University Sapporo Hokkaido Japan
| | - Kikuo Umegaki
- Faculty of Engineering Hokkaido University Sapporo Hokkaido Japan
- Proton Beam Therapy Center Hokkaido University Hospital Sapporo Hokkaido Japan
- Department of Medical Physics Hokkaido University Hospital Sapporo Hokkaido Japan
| | - Taeko Matsuura
- Faculty of Engineering Hokkaido University Sapporo Hokkaido Japan
- Proton Beam Therapy Center Hokkaido University Hospital Sapporo Hokkaido Japan
- Department of Medical Physics Hokkaido University Hospital Sapporo Hokkaido Japan
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Mein S, Kopp B, Vela A, Dutheil P, Lesueur P, Stefan D, Debus J, Haberer T, Abdollahi A, Mairani A, Tessonnier T. How can we consider variable RBE and LET d prediction during clinical practice? A pediatric case report at the Normandy Proton Therapy Centre using an independent dose engine. Radiat Oncol 2022; 17:23. [PMID: 35120547 PMCID: PMC8815260 DOI: 10.1186/s13014-021-01960-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 12/01/2021] [Indexed: 11/25/2022] Open
Abstract
Background To develop an auxiliary GPU-accelerated proton therapy (PT) dose and LETd engine for the IBA Proteus®ONE PT system. A pediatric low-grade glioma case study is reported using FRoG during clinical practice, highlighting potential treatment planning insights using variable RBE dose (DvRBE) and LETd as indicators for clinical decision making in PT. Methods The physics engine for FRoG has been modified for compatibility with Proteus®ONE PT centers. Subsequently, FRoG was installed and commissioned at NPTC. Dosimetric validation was performed against measurements and the clinical TPS, RayStation (RS-MC). A head patient cohort previously treated at NPTC was collected and FRoG forward calculations were compared against RS-MC for evaluation of 3D-Γ analysis and dose volume histogram (DVH) results. Currently, treatment design at NPTC is supported with fast variable RBE and LETd calculation and is reported in a representative case for pediatric low-grade glioma. Results Simple dosimetric tests against measurements of iso-energy layers and spread-out Bragg Peaks in water verified accuracy of FRoG and RS-MC. Among the patient cohort, average 3D-Γ applying 2%/2 mm, 3%/1.5 mm and 5%/1 mm were > 97%. DVH metrics for targets and OARs between FRoG and RayStation were in good agreement, with ∆D50,CTV and ∆D2,OAR both ⪅1%. The pediatric case report demonstrated implications of different beam arrangements on DvRBE and LETd distributions. From initial planning in RayStation sharing identical optimization constraints, FRoG analysis led to plan selection of the most conservative approach, i.e., minimized DvRBE,max and LETd,max in OARs, to avoid optical system toxicity effects (i.e., vision loss). Conclusion An auxiliary dose calculation system was successfully integrated into the clinical workflow at a Proteus®ONE IBA facility, in excellent agreement with measurements and RS-MC. FRoG may lead to further insight on DvRBE and LETd implications to help clinical decision making, better understand unexpected toxicities and establish novel clinical procedures with metrics currently absent from the standard clinical TPS.
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Affiliation(s)
- Stewart Mein
- Division of Molecular and Translational Radiation Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), German Cancer Research Center (DKFZ), Heidelberg, Germany.,German Cancer Consortium (DKTK), Heidelberg, Germany.,Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg Ion-beam Therapy Center (HIT), In Neuenheimer Feld (INF) 450, DE, 69120, Heidelberg, Germany
| | - Benedikt Kopp
- Division of Molecular and Translational Radiation Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), German Cancer Research Center (DKFZ), Heidelberg, Germany.,German Cancer Consortium (DKTK), Heidelberg, Germany.,Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg Ion-beam Therapy Center (HIT), In Neuenheimer Feld (INF) 450, DE, 69120, Heidelberg, Germany.,Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany
| | - Anthony Vela
- Radiation Oncology Department, Centre François Baclesse, Caen, France
| | - Pauline Dutheil
- Radiation Oncology Department, Centre François Baclesse, Caen, France
| | - Paul Lesueur
- Radiation Oncology Department, Centre François Baclesse, Caen, France.,Radiation Oncology Department, Centre Guillaume Le Conquérant, Le Havre, France.,ISTCT UMR6030-CNRS, CEA, Université de Caen-Normandie, Equipe CERVOxy, Caen, France
| | - Dinu Stefan
- Radiation Oncology Department, Centre François Baclesse, Caen, France
| | - Jürgen Debus
- Division of Molecular and Translational Radiation Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), German Cancer Research Center (DKFZ), Heidelberg, Germany.,German Cancer Consortium (DKTK), Heidelberg, Germany.,Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg Ion-beam Therapy Center (HIT), In Neuenheimer Feld (INF) 450, DE, 69120, Heidelberg, Germany
| | - Thomas Haberer
- Heidelberg Ion-beam Therapy Center (HIT), In Neuenheimer Feld (INF) 450, DE, 69120, Heidelberg, Germany
| | - Amir Abdollahi
- Division of Molecular and Translational Radiation Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), German Cancer Research Center (DKFZ), Heidelberg, Germany.,German Cancer Consortium (DKTK), Heidelberg, Germany.,Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg Ion-beam Therapy Center (HIT), In Neuenheimer Feld (INF) 450, DE, 69120, Heidelberg, Germany
| | - Andrea Mairani
- Division of Molecular and Translational Radiation Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, Heidelberg, Germany.,Heidelberg Ion-beam Therapy Center (HIT), In Neuenheimer Feld (INF) 450, DE, 69120, Heidelberg, Germany.,National Centre of Oncological Hadrontherapy (CNAO), Medical Physics, Pavia, Italy
| | - Thomas Tessonnier
- Division of Molecular and Translational Radiation Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, Heidelberg, Germany. .,Heidelberg Ion-beam Therapy Center (HIT), In Neuenheimer Feld (INF) 450, DE, 69120, Heidelberg, Germany. .,Radiation Oncology Department, Centre François Baclesse, Caen, France.
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44
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Paganetti H. Mechanisms and Review of Clinical Evidence of Variations in Relative Biological Effectiveness in Proton Therapy. Int J Radiat Oncol Biol Phys 2022; 112:222-236. [PMID: 34407443 PMCID: PMC8688199 DOI: 10.1016/j.ijrobp.2021.08.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 07/14/2021] [Accepted: 08/10/2021] [Indexed: 01/03/2023]
Abstract
Proton therapy is increasingly being used as a radiation therapy modality. There is uncertainty about the biological effectiveness of protons relative to photon therapies as it depends on several physical and biological parameters. Radiation oncology currently applies a constant and generic value for the relative biological effectiveness (RBE) of 1.1, which was chosen conservatively to ensure tumor coverage. The use of a constant value has been challenged particularly when considering normal tissue constraints. Potential variations in RBE have been assessed in several published reviews but have mostly focused on data from clonogenic cell survival experiments with unclear relevance for clinical proton therapy. The goal of this review is to put in vitro findings in relation to clinical observations. Relevant in vivo pathways determining RBE for tumors and normal tissues are outlined, including not only damage to tumor cells and parenchyma but also vascular damage and immune response. Furthermore, the current clinical evidence of varying RBE is reviewed. The assessment can serve as guidance for treatment planning, personalized dose prescriptions, and outcome analysis.
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Affiliation(s)
- Harald Paganetti
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA.
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45
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Smith EAK, Winterhalter C, Underwood TSA, Aitkenhead AH, Richardson JC, Merchant MJ, Kirkby NF, Kirby KJ, Mackay RI. A Monte Carlo study of different LET definitions and calculation parameters for proton beam therapy. Biomed Phys Eng Express 2021; 8. [PMID: 34874308 DOI: 10.1088/2057-1976/ac3f50] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 12/02/2021] [Indexed: 12/19/2022]
Abstract
The strongin vitroevidence that proton Relative Biological Effectiveness (RBE) varies with Linear Energy Transfer (LET) has led to an interest in applying LET within treatment planning. However, there is a lack of consensus on LET definition, Monte Carlo (MC) parameters or clinical methodology. This work aims to investigate how common variations of LET definition may affect potential clinical applications. MC simulations (GATE/GEANT4) were used to calculate absorbed dose and different types of LET for a simple Spread Out Bragg Peak (SOBP) and for four clinical PBT plans covering a range of tumour sites. Variations in the following LET calculation methods were considered: (i) averaging (dose-averaged LET (LETd) & track-averaged LET); (ii) scoring (LETdto water, to medium and to mass density); (iii) particle inclusion (LETdto all protons, to primary protons and to particles); (iv) MC settings (hit type and Maximum Step Size (MSS)). LET distributions were compared using: qualitative comparison, LET Volume Histograms (LVHs), single value criteria (maximum and mean values) and optimised LET-weighted dose models. Substantial differences were found between LET values in averaging, scoring and particle type. These differences depended on the methodology, but for one patient a difference of ∼100% was observed between the maximum LETdfor all particles and maximum LETdfor all protons within the brainstem in the high isodose region (4 keVμm-1and 8 keVμm-1respectively). An RBE model using LETdincluding heavier ions was found to predict substantially different LET-weighted dose compared to those using other LET definitions. In conclusion, the selection of LET definition may affect the results of clinical metrics considered in treatment planning and the results of an RBE model. The authors' advocate for the scoring of dose-averaged LET to water for primary and secondary protons using a random hit type and automated MSS.
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Affiliation(s)
- Edward A K Smith
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Carla Winterhalter
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,The Christie NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Tracy S A Underwood
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,The Christie NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Adam H Aitkenhead
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Jenny C Richardson
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Michael J Merchant
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,The Christie NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Norman F Kirkby
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,The Christie NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Karen J Kirby
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,The Christie NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Ranald I Mackay
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, United Kingdom
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46
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Rucinski A, Biernacka A, Schulte R. Applications of nanodosimetry in particle therapy planning and beyond. Phys Med Biol 2021; 66. [PMID: 34731854 DOI: 10.1088/1361-6560/ac35f1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 11/03/2021] [Indexed: 12/28/2022]
Abstract
This topical review summarizes underlying concepts of nanodosimetry. It describes the development and current status of nanodosimetric detector technology. It also gives an overview of Monte Carlo track structure simulations that can provide nanodosimetric parameters for treatment planning of proton and ion therapy. Classical and modern radiobiological assays that can be used to demonstrate the relationship between the frequency and complexity of DNA lesion clusters and nanodosimetric parameters are reviewed. At the end of the review, existing approaches of treatment planning based on relative biological effectiveness (RBE) models or dose-averaged linear energy transfer are contrasted with an RBE-independent approach based on nandosimetric parameters. Beyond treatment planning, nanodosimetry is also expected to have applications and give new insights into radiation protection dosimetry.
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Affiliation(s)
| | - Anna Biernacka
- University of Gdansk, Intercollegiate Faculty of Biotechnology of University of Gdańsk and Medical University of Gdansk, 80-307 Gdansk, Poland
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47
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Feng H, Shan J, Anderson JD, Wong WW, Schild SE, Foote RL, Patrick CL, Tinnon KB, Fatyga M, Bues M, Patel SH, Liu W. Per-voxel constraints to minimize hot spots in linear energy transfer-guided robust optimization for base of skull head and neck cancer patients in IMPT. Med Phys 2021; 49:632-647. [PMID: 34843119 DOI: 10.1002/mp.15384] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 11/03/2021] [Accepted: 11/16/2021] [Indexed: 11/11/2022] Open
Abstract
PURPOSE Due to the employment of quadratic programming using soft constraints to implement dose volume constraints and the "trial-and-error" procedure needed to achieve a clinically acceptable plan, conventional dose volume constraints (upper limit) are not adequately effective in controlling small and isolated hot spots in the dose/linear energy transfer (LET) distribution. Such hot spots can lead to adverse events. In order to mitigate the risk of brain necrosis, one of the most clinically significant adverse events in patients receiving intensity-modulated proton therapy (IMPT) for base of skull (BOS) cancer, we propose per-voxel constraints to minimize hot spots in LET-guided robust optimization. METHODS AND MATERIALS Ten BOS cancer patients treated with IMPT were carefully selected by meeting one of the following conditions: (1) diagnosis of brain necrosis during follow-up; and (2) considered high risk for brain necrosis by not meeting dose constraints to the brain. An optimizing structure (BrainOPT) and an evaluating structure (BrainROI) that both contained the aforementioned hot dose regions in the brain were generated for optimization and evaluation, respectively. Two plans were generated for every patient: one using conventional dose-only robust optimization, the other using LET-guided robust optimization. The impact of LET was integrated into the optimization via a term of extra biological dose (xBD). A novel optimization tool of per-voxel constraints to control small and isolated hot spots in either the dose, LET, or combined (dose/LET) distribution was developed and used to minimize dose/LET hot spots of the selected structures. Indices from dose-volume histogram (DVH) and xBD dose-volume histogram (xBDVH) were used in the plan evaluation. A newly developed tool of the dose-LET-volume histogram (DLVH) was also adopted to illustrate the underlying mechanism. Wilcoxon signed-rank test was used for statistical comparison of the DVH and xBDVH indices between the conventional dose-only and the LET-guided robustly optimized plans. RESULTS Per-voxel constraints effectively and efficiently minimized dose hot spots in both dose-only and LET-guided robust optimization and LET hot spots in LET-guided robust optimization. Compared to the conventional dose-only robust optimization, the LET-guided robust optimization could generate plans with statistically lower xBD hot spots in BrainROI (VxBD,50 Gy[RBE], p = 0.009; VxBD,60 Gy[RBE], p = 0.025; xBD1cc, p = 0.017; xBD2cc, p = 0.022) with comparable dose coverage, dose hot spots in the target, and dose hot spots in BrainROI. DLVH analysis indicated that LET-guided robust optimization could either reduce LET at the same dose level or redistribute high LET from high dose regions to low dose regions. CONCLUSION Per-voxel constraint is a powerful tool to minimize dose/LET hot spots in IMPT. The LET-guided robustly optimized plans outperformed the conventional dose-only robustly optimized plans in terms of xBD hot spots control.
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Affiliation(s)
- Hongying Feng
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, USA
| | - Jie Shan
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, USA
| | - Justin D Anderson
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, USA
| | - William W Wong
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, USA
| | - Steven E Schild
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, USA
| | - Robert L Foote
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Kathryn B Tinnon
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, USA
| | - Mirek Fatyga
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, USA
| | - Martin Bues
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, USA
| | - Samir H Patel
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, USA
| | - Wei Liu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, USA
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48
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Paganetti H, Botas P, Sharp GC, Winey B. Adaptive proton therapy. Phys Med Biol 2021; 66:10.1088/1361-6560/ac344f. [PMID: 34710858 PMCID: PMC8628198 DOI: 10.1088/1361-6560/ac344f] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/28/2021] [Indexed: 12/25/2022]
Abstract
Radiation therapy treatments are typically planned based on a single image set, assuming that the patient's anatomy and its position relative to the delivery system remains constant during the course of treatment. Similarly, the prescription dose assumes constant biological dose-response over the treatment course. However, variations can and do occur on multiple time scales. For treatment sites with significant intra-fractional motion, geometric changes happen over seconds or minutes, while biological considerations change over days or weeks. At an intermediate timescale, geometric changes occur between daily treatment fractions. Adaptive radiation therapy is applied to consider changes in patient anatomy during the course of fractionated treatment delivery. While traditionally adaptation has been done off-line with replanning based on new CT images, online treatment adaptation based on on-board imaging has gained momentum in recent years due to advanced imaging techniques combined with treatment delivery systems. Adaptation is particularly important in proton therapy where small changes in patient anatomy can lead to significant dose perturbations due to the dose conformality and finite range of proton beams. This review summarizes the current state-of-the-art of on-line adaptive proton therapy and identifies areas requiring further research.
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Affiliation(s)
- Harald Paganetti
- Department of Radiation Oncology, Physics Division, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Pablo Botas
- Department of Radiation Oncology, Physics Division, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
- Foundation 29 of February, Pozuelo de Alarcón, Madrid, Spain
| | - Gregory C Sharp
- Department of Radiation Oncology, Physics Division, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Brian Winey
- Department of Radiation Oncology, Physics Division, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
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49
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Henjum H, Dahle TJ, Fjæra LF, Rørvik E, Pilskog S, Stokkevåg CH, Mairani A, Ytre-Hauge KS. The Organ Sparing Potential of Different Biological Optimization Strategies in Proton Therapy. Adv Radiat Oncol 2021; 6:100776. [PMID: 34765804 PMCID: PMC8573123 DOI: 10.1016/j.adro.2021.100776] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 06/20/2021] [Accepted: 08/09/2021] [Indexed: 02/03/2023] Open
Abstract
Purpose Variable relative biological effectiveness (RBE) models allow for differences in linear energy transfer (LET), physical dose, and tissue type to be accounted for when quantifying and optimizing the biological damage of protons. These models are complex and fraught with uncertainties, and therefore, simpler RBE optimization strategies have also been suggested. Our aim was to compare several biological optimization strategies for proton therapy by evaluating their performance in different clinical cases. Methods and Materials Two different optimization strategies were compared: full variable RBE optimization and differential RBE optimization, which involve applying fixed RBE for the planning target volume (PTV) and variable RBE in organs at risk (OARs). The optimization strategies were coupled to 2 variable RBE models and 1 LET-weighted dose model, with performance demonstrated on 3 different clinical cases: brain, head and neck, and prostate tumors. Results In cases with low (α/β)x in the tumor, the full RBE optimization strategies had a large effect, with up to 10% reduction in RBE-weighted dose to the PTV and OARs compared with the reference plan, whereas smaller variations (<5%) were obtained with differential optimization. For tumors with high (α/β)x, the differential RBE optimization strategy showed a greater reduction in RBE-weighted dose to the OARs compared with the reference plan and the full RBE optimization strategy. Conclusions Differences between the optimization strategies varied across the studied cases, influenced by both biological and physical parameters. Whereas full RBE optimization showed greater OAR sparing, awareness of underdosage to the target must be carefully considered.
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Affiliation(s)
- Helge Henjum
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Corresponding author: Helge Henjum, MSc
| | - Tordis J. Dahle
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| | - Lars Fredrik Fjæra
- Department of Physics and Technology, University of Bergen, Bergen, Norway
| | - Eivind Rørvik
- Department of Physics and Technology, University of Bergen, Bergen, Norway
| | - Sara Pilskog
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| | - Camilla H. Stokkevåg
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| | - Andrea Mairani
- Centro Nazionale di Adroterapia Oncologica (CNAO Foundation), Pavia, Italy
- Heidelberg Ion Beam Therapy Center, Heidelberg, Germany
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50
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Wagenaar D, Schuit E, van der Schaaf A, Langendijk JA, Both S. Can the mean linear energy transfer of organs be directly related to patient toxicities for current head and neck cancer intensity-modulated proton therapy practice? Radiother Oncol 2021; 165:159-165. [PMID: 34534614 DOI: 10.1016/j.radonc.2021.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 08/05/2021] [Accepted: 09/04/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND AND PURPOSE The relative biological effectiveness (RBE) of proton therapy is predicted to vary with the dose-weighted average linear energy transfer (LETd). However, RBE values may substantially vary for different clinical endpoints. Therefore, the aim of this study was to assess the feasibility of relating mean D⋅LETd parameters to patient toxicity for HNC patients treated with proton therapy. MATERIALS AND METHODS The delivered physical dose (D) and the voxel-wise product of D and LETd (D⋅LETd) distributions were calculated for 100 head and neck cancer (HNC) proton therapy patients using our TPS (Raystation v6R). The means and covariance matrix of the accumulated D and D⋅LETd of all relevant organs-at-risk (OARs) were used to simulate 2.500 data sets of different sizes. For each dataset, an attempt was made to add mean D⋅LETd parameters to a multivariable NTCP model based on mean D parameters of the same OAR for xerostomia, tube feeding and dysphagia. The likelihood of creating an NTCP model with statistically significant parameters (i.e. power) was calculated as a function of the simulated sample size for various RBE models. RESULTS The sample size required to have a power of at least 80% to show an independent effect of mean D⋅LETd parameters on toxicity is over 15,000 patients for all toxicities. CONCLUSION For current clinical practice, it is not feasible to directly model NTCP with both mean D and mean D⋅LETd of OARs. These findings should not be interpreted as a contradiction of previous evidence for the relationship between RBE and LETd.
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Affiliation(s)
- Dirk Wagenaar
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, the Netherlands.
| | - Ewoud Schuit
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Arjen van der Schaaf
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, the Netherlands
| | - Johannes A Langendijk
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, the Netherlands
| | - Stefan Both
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, the Netherlands
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