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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] [Grants] [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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Yao W, Farr JB, Mossahebi S, Yi B, Chen S. Technical note: Determination of proton linear energy transfer from the integral depth dose. Med Phys 2024; 51:5148-5153. [PMID: 38043083 DOI: 10.1002/mp.16866] [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: 07/20/2023] [Revised: 11/13/2023] [Accepted: 11/14/2023] [Indexed: 12/05/2023] Open
Abstract
BACKGROUND Proton linear energy transfer (LET) is associated with the relative biological effectiveness of radiation on tissues. Monte Carlo (MC) simulations have been known to be the preferred method to calculate LET. Detectors have also been built to measure LET, but they need to be calibrated with MC simulations. PURPOSE To propose and test a MC-free method for determining LET from the measured integral depth dose (LFI) of the protons of interest. METHOD AND MATERIALS LFI consists of three steps: (1) IDD measurements, (2) extraction of energy spectrum (ES) from the IDD, and (3) LET determination from the extracted ES and the stopping power of each energy. To validate the accuracy of the extraction of ES, we use Gaussian ES to synthesize IDD, extract ES from the synthesized IDD, and then compare the original (ground truth) and extracted ES. LETs calculated from the original and extracted ES are also compared. To obtain the LET of protons of interest, we measure IDDs by a large-area plane-parallel ionization chamber in water. Finally, TOPAS MC is employed to simulate IDDs, ES, and LETs. From the simulated IDD, the extracted ES and LET are compared with the simulations from TOPAS MC. RESULTS From the synthesized IDDs, the LETs agreed excellently when the peak energies ≥10 and 1.25 MeV with depth resolutions 0.1 and 0.01 mm, respectively. For energy <1.25 MeV, even higher depth resolution than 0.01 mm is required. From the MC simulated IDDs, our track-averaged LET excellently agreed with MC simulation, but not the LETd. Our LETd was smaller than MC simulated LETd in the shallow region but larger in the distal Bragg peak region. CONCLUSION LET can be accurately determined from the IDD. This method can be used in the clinic to commission or validate LETs from other measurement methods or a treatment planning system.
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Affiliation(s)
- Weiguang Yao
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Jonathan B Farr
- Department of Medical Physics, Applications of Detectors and Accelerators to Medicine, Meyrin, Switzerland
| | - Sina Mossahebi
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Byongyong Yi
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Shifeng Chen
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Harrison N, Kang M, Liu R, Charyyev S, Wahl N, Liu W, Zhou J, Higgins KA, Simone CB, Bradley JD, Dynan WS, Lin L. A Novel Inverse Algorithm To Solve the Integrated Optimization of Dose, Dose Rate, and Linear Energy Transfer of Proton FLASH Therapy With Sparse Filters. Int J Radiat Oncol Biol Phys 2024; 119:957-967. [PMID: 38104869 DOI: 10.1016/j.ijrobp.2023.11.061] [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: 04/20/2023] [Revised: 09/27/2023] [Accepted: 11/25/2023] [Indexed: 12/19/2023]
Abstract
PURPOSE The recently proposed Integrated Physical Optimization Intensity Modulated Proton Therapy (IPO-IMPT) framework allows simultaneous optimization of dose, dose rate, and linear energy transfer (LET) for ultra-high dose rate (FLASH) treatment planning. Finding solutions to IPO-IMPT is difficult because of computational intensiveness. Nevertheless, an inverse solution that simultaneously specifies the geometry of a sparse filter and weights of a proton intensity map is desirable for both clinical and preclinical applications. Such solutions can reduce effective biologic dose to organs at risk in patients with cancer as well as reduce the number of animal irradiations needed to derive extra biologic dose models in preclinical studies. METHODS AND MATERIALS Unlike the initial forward heuristic, this inverse IPO-IMPT solution includes simultaneous optimization of sparse range compensation, sparse range modulation, and spot intensity. The daunting computational tasks vital to this endeavor were resolved iteratively with a distributed computing framework to enable Simultaneous Intensity and Energy Modulation and Compensation (SIEMAC). SIEMAC was demonstrated on a human patient with central lung cancer and a minipig. RESULTS SIEMAC simultaneously improves maps of spot intensities and patient-field-specific sparse range compensators and range modulators. For the patient with lung cancer, at our maximum nozzle current of 300 nA, dose rate coverage above 100 Gy/s increased from 57% to 96% in the lung and from 93% to 100% in the heart, and LET coverage above 4 keV/µm dropped from 68% to 9% in the lung and from 26% to <1% in the heart. For a simple minipig plan, the full-width half-maximum of the dose, dose rate, and LET distributions decreased by 30%, 1.6%, and 57%, respectively, again with similar target dose coverage, thus reducing uncertainty in these quantities for preclinical studies. CONCLUSIONS The inverse solution to IPO-IMPT demonstrated the capability to simultaneously modulate subspot proton energy and intensity distributions for clinical and preclinical studies.
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Affiliation(s)
| | | | - Ruirui Liu
- Emory University, Atlanta, Georgia; University of Nebraska, Omaha, Nebraska
| | | | - Niklas Wahl
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Wei Liu
- Mayo Clinic, Phoenix, Arizona
| | - Jun Zhou
- Emory University, Atlanta, Georgia
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Tang X, Wan Chan Tseung H, Moseley D, Zverovitch A, Hughes CO, George J, Johnson JE, Breen WG, Qian J. Deep learning based linear energy transfer calculation for proton therapy. Phys Med Biol 2024; 69:115058. [PMID: 38714191 DOI: 10.1088/1361-6560/ad4844] [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: 11/01/2023] [Accepted: 05/07/2024] [Indexed: 05/09/2024]
Abstract
Objective.This study aims to address the limitations of traditional methods for calculating linear energy transfer (LET), a critical component in assessing relative biological effectiveness (RBE). Currently, Monte Carlo (MC) simulation, the gold-standard for accuracy, is resource-intensive and slow for dose optimization, while the speedier analytical approximation has compromised accuracy. Our objective was to prototype a deep-learning-based model for calculating dose-averaged LET (LETd) using patient anatomy and dose-to-water (DW) data, facilitating real-time biological dose evaluation and LET optimization within proton treatment planning systems.Approach. 275 4-field prostate proton Stereotactic Body Radiotherapy plans were analyzed, rendering a total of 1100 fields. Those were randomly split into 880, 110, and 110 fields for training, validation, and testing. A 3D Cascaded UNet model, along with data processing and inference pipelines, was developed to generate patient-specific LETddistributions from CT images and DW. The accuracy of the LETdof the test dataset was evaluated against MC-generated ground truth through voxel-based mean absolute error (MAE) and gamma analysis.Main results.The proposed model accurately inferred LETddistributions for each proton field in the test dataset. A single-field LETdcalculation took around 100 ms with trained models running on a NVidia A100 GPU. The selected model yielded an average MAE of 0.94 ± 0.14 MeV cm-1and a gamma passing rate of 97.4% ± 1.3% when applied to the test dataset, with the largest discrepancy at the edge of fields where the dose gradient was the largest and counting statistics was the lowest.Significance.This study demonstrates that deep-learning-based models can efficiently calculate LETdwith high accuracy as a fast-forward approach. The model shows great potential to be utilized for optimizing the RBE of proton treatment plans. Future efforts will focus on enhancing the model's performance and evaluating its adaptability to different clinical scenarios.
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Affiliation(s)
- Xueyan Tang
- Department of Radiation Oncology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States of America
| | - Hok Wan Chan Tseung
- Department of Radiation Oncology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States of America
| | - Douglas Moseley
- Department of Radiation Oncology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States of America
| | | | - Cian O Hughes
- Google Inc, Mountain View, CA, United States of America
| | - Jon George
- Google Inc, Mountain View, CA, United States of America
| | - Jedediah E Johnson
- Department of Radiation Oncology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States of America
| | - William G Breen
- Department of Radiation Oncology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States of America
| | - Jing Qian
- Department of Radiation Oncology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States of America
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Matias F, Silva TF, Koval NE, Pereira JJN, Antunes PCG, Siqueira PTD, Tabacniks MH, Yoriyaz H, Shorto JMB, Grande PL. Efficient computational modeling of electronic stopping power of organic polymers for proton therapy optimization. Sci Rep 2024; 14:9868. [PMID: 38684890 PMCID: PMC11058815 DOI: 10.1038/s41598-024-60651-0] [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: 02/05/2024] [Accepted: 04/25/2024] [Indexed: 05/02/2024] Open
Abstract
This comprehensive study delves into the intricate interplay between protons and organic polymers, offering insights into proton therapy in cancer treatment. Focusing on the influence of the spatial electron density distribution on stopping power estimates, we employed real-time time-dependent density functional theory coupled with the Penn method. Surprisingly, the assumption of electron density homogeneity in polymers is fundamentally flawed, resulting in an overestimation of stopping power values at energies below 2 MeV. Moreover, the Bragg rule application in specific compounds exhibited significant deviations from experimental data around the stopping maximum, challenging established norms.
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Affiliation(s)
- F Matias
- Instituto de Pesquisas Energéticas e Nucleares, Av. Professor Lineu Prestes, São Paulo, 05508-000, Brazil.
| | - T F Silva
- Instituto de Física da Universidade de São Paulo, Rua do Matão, trav. R187, São Paulo, 05508-090, Brazil
| | - N E Koval
- Centro de Física de Materiales, Paseo Manuel de Lardizabal 5, Donostia-San Sebastián, 20018, Spain
| | - J J N Pereira
- Instituto de Pesquisas Energéticas e Nucleares, Av. Professor Lineu Prestes, São Paulo, 05508-000, Brazil
| | - P C G Antunes
- Instituto de Pesquisas Energéticas e Nucleares, Av. Professor Lineu Prestes, São Paulo, 05508-000, Brazil
| | - P T D Siqueira
- Instituto de Pesquisas Energéticas e Nucleares, Av. Professor Lineu Prestes, São Paulo, 05508-000, Brazil
| | - M H Tabacniks
- Instituto de Física da Universidade de São Paulo, Rua do Matão, trav. R187, São Paulo, 05508-090, Brazil
| | - H Yoriyaz
- Instituto de Pesquisas Energéticas e Nucleares, Av. Professor Lineu Prestes, São Paulo, 05508-000, Brazil
| | - J M B Shorto
- Instituto de Pesquisas Energéticas e Nucleares, Av. Professor Lineu Prestes, São Paulo, 05508-000, Brazil
| | - P L Grande
- Instituto de Física da Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, Porto Alegre, 9500, Brazil
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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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7
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Voshart DC, Klaver M, Jiang Y, van Weering HRJ, van Buuren-Broek F, van der Linden GP, Cinat D, Kiewiet HH, Malimban J, Vazquez-Matias DA, Reali Nazario L, Scholma AC, Sewdihal J, van Goethem MJ, van Luijk P, Coppes RP, Barazzuol L. Proton therapy induces a local microglial neuroimmune response. Radiother Oncol 2024; 193:110117. [PMID: 38453539 DOI: 10.1016/j.radonc.2024.110117] [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: 06/15/2023] [Revised: 01/25/2024] [Accepted: 01/28/2024] [Indexed: 03/09/2024]
Abstract
BACKGROUND AND PURPOSE Although proton therapy is increasingly being used in the treatment of paediatric and adult brain tumours, there are still uncertainties surrounding the biological effect of protons on the normal brain. Microglia, the brain-resident macrophages, have been shown to play a role in the development of radiation-induced neurotoxicity. However, their molecular and hence functional response to proton irradiation remains unknown. This study investigates the effect of protons on microglia by comparing the effect of photons and protons as well as the influence of age and different irradiated volumes. MATERIALS AND METHODS Rats were irradiated with 14 Gy to the whole brain with photons (X-rays), plateau protons, spread-out Bragg peak (SOBP) protons or to 50 % anterior, or 50 % posterior brain sub-volumes with plateau protons. RNA sequencing, validation of microglial priming gene expression using qPCR and high-content imaging analysis of microglial morphology were performed in the cortex at 12 weeks post irradiation. RESULTS Photons and plateau protons induced a shared transcriptomic response associated with neuroinflammation. This response was associated with a similar microglial priming gene expression signature and distribution of microglial morphologies. Expression of the priming gene signature was less pronounced in juvenile rats compared to adults and slightly increased in rats irradiated with SOBP protons. High-precision partial brain irradiation with protons induced a local microglial priming response and morphological changes. CONCLUSION Overall, our data indicate that the brain responds in a similar manner to photons and plateau protons with a shared local upregulation of microglial priming-associated genes, potentially enhancing the immune response to subsequent inflammatory challenges.
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Affiliation(s)
- Daniëlle C Voshart
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, The Netherlands; Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, Groningen 9700 AD, The Netherlands
| | - Myrthe Klaver
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, The Netherlands; Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, Groningen 9700 AD, The Netherlands
| | - Yuting Jiang
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, The Netherlands; Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, Groningen 9700 AD, The Netherlands
| | - Hilmar R J van Weering
- Department of Biomedical Sciences, Section of Molecular Neurobiology, University Medical Center Groningen, University of Groningen, Groningen 9700 AD, The Netherlands
| | - Fleur van Buuren-Broek
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, The Netherlands; Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, Groningen 9700 AD, The Netherlands
| | - Gideon P van der Linden
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, The Netherlands; Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, Groningen 9700 AD, The Netherlands
| | - Davide Cinat
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, The Netherlands; Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, Groningen 9700 AD, The Netherlands
| | - Harry H Kiewiet
- Department of Biomedical Sciences, PARTREC, University Medical Center Groningen, University of Groningen, Groningen 9747 AA, The Netherlands
| | - Justin Malimban
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, The Netherlands
| | - Daniel A Vazquez-Matias
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, The Netherlands; Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, Groningen 9700 AD, The Netherlands
| | - Luiza Reali Nazario
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, The Netherlands; Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, Groningen 9700 AD, The Netherlands
| | - Ayla C Scholma
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, The Netherlands; Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, Groningen 9700 AD, The Netherlands
| | - Jeffrey Sewdihal
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, The Netherlands; Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, Groningen 9700 AD, The Netherlands
| | - Marc-Jan van Goethem
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, The Netherlands; Department of Biomedical Sciences, PARTREC, University Medical Center Groningen, University of Groningen, Groningen 9747 AA, The Netherlands
| | - Peter van Luijk
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, The Netherlands; Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, Groningen 9700 AD, The Netherlands
| | - Rob P Coppes
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, The Netherlands; Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, Groningen 9700 AD, The Netherlands
| | - Lara Barazzuol
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, The Netherlands; Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, Groningen 9700 AD, The Netherlands.
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Nachankar A, Schafasand M, Hug E, Martino G, Góra J, Carlino A, Stock M, Fossati P. Sacral-Nerve-Sparing Planning Strategy in Pelvic Sarcomas/Chordomas Treated with Carbon-Ion Radiotherapy. Cancers (Basel) 2024; 16:1284. [PMID: 38610962 PMCID: PMC11010899 DOI: 10.3390/cancers16071284] [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: 02/01/2024] [Revised: 03/20/2024] [Accepted: 03/23/2024] [Indexed: 04/14/2024] Open
Abstract
To minimize radiation-induced lumbosacral neuropathy (RILSN), we employed sacral-nerve-sparing optimized carbon-ion therapy strategy (SNSo-CIRT) in treating 35 patients with pelvic sarcomas/chordomas. Plans were optimized using Local Effect Model-I (LEM-I), prescribed DRBE|LEM-I|D50% (median dose to HD-PTV) = 73.6 (70.4-76.8) Gy (RBE)/16 fractions. Sacral nerves were contoured between L5-S3 levels. DRBE|LEM-I to 5% of sacral nerves-to-spare (outside HD-CTV) (DRBE|LEM-I|D5%) were restricted to <69 Gy (RBE). The median follow-up was 25 months (range of 2-53). Three patients (9%) developed late RILSN (≥G3) after an average period of 8 months post-CIRT. The RILSN-free survival at 2 years was 91% (CI, 81-100). With SNSo-CIRT, DRBE|LEM-I|D5% for sacral nerves-to-spare = 66.9 ± 1.9 Gy (RBE), maintaining DRBE|LEM-I to 98% of HD-CTV (DRBE|LEM-I|D98%) = 70 ± 3.6 Gy (RBE). Two-year OS and LC were 100% and 93% (CI, 84-100), respectively. LETd and DRBE with modified-microdosimetric kinetic model (mMKM) were recomputed retrospectively. DRBE|LEM-I and DRBE|mMKM were similar, but DRBE-filtered-LETd was higher in sacral nerves-to-spare in patients with RILSN than those without. At DRBE|LEM-I cutoff = 64 Gy (RBE), 2-year RILSN-free survival was 100% in patients with <12% of sacral nerves-to-spare voxels receiving LETd > 55 keV/µm than 75% (CI, 54-100) in those with ≥12% of voxels (p < 0.05). DRBE-filtered-LETd holds promise for the SNSo-CIRT strategy but requires longer follow-up for validation.
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Affiliation(s)
- Ankita Nachankar
- ACMIT Gmbh, 2700 Wiener Neustadt, Austria
- Department of Radiation Oncology, MedAustron Ion Therapy Center, 2700 Wiener Neustadt, Austria; (E.H.); (P.F.)
| | - Mansure Schafasand
- Department of Medical Physics, MedAustron Ion Therapy Center, 2700 Wiener Neustadt, Austria; (M.S.); (G.M.); (J.G.); (A.C.); (M.S.)
- Department of Radiation Oncology, Medical University of Vienna, 1090 Wien, Austria
- Division Medical Physics, Karl Landsteiner University of Health Sciences, 3500 Krems an der Donau, Austria
| | - Eugen Hug
- Department of Radiation Oncology, MedAustron Ion Therapy Center, 2700 Wiener Neustadt, Austria; (E.H.); (P.F.)
| | - Giovanna Martino
- Department of Medical Physics, MedAustron Ion Therapy Center, 2700 Wiener Neustadt, Austria; (M.S.); (G.M.); (J.G.); (A.C.); (M.S.)
| | - Joanna Góra
- Department of Medical Physics, MedAustron Ion Therapy Center, 2700 Wiener Neustadt, Austria; (M.S.); (G.M.); (J.G.); (A.C.); (M.S.)
| | - Antonio Carlino
- Department of Medical Physics, MedAustron Ion Therapy Center, 2700 Wiener Neustadt, Austria; (M.S.); (G.M.); (J.G.); (A.C.); (M.S.)
| | - Markus Stock
- Department of Medical Physics, MedAustron Ion Therapy Center, 2700 Wiener Neustadt, Austria; (M.S.); (G.M.); (J.G.); (A.C.); (M.S.)
- Division Medical Physics, Karl Landsteiner University of Health Sciences, 3500 Krems an der Donau, Austria
| | - Piero Fossati
- Department of Radiation Oncology, MedAustron Ion Therapy Center, 2700 Wiener Neustadt, Austria; (E.H.); (P.F.)
- Division Radiation Oncology, Karl Landsteiner University of Health Sciences, 3500 Krems an der Donau, Austria
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9
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Yan N, Wu C, Zhou Y, Liao W, Liu J, Pu Y. A linear energy transfer distributions computation method for inhomogeneous medium by using the water equivalent ratio approximation. RADIATION PROTECTION DOSIMETRY 2024; 200:325-332. [PMID: 37850312 DOI: 10.1093/rpd/ncad273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 07/26/2023] [Accepted: 09/19/2023] [Indexed: 10/19/2023]
Abstract
Dose-averaged linear energy transfer (LET), LETd is widely used in proton therapy. Compared with analytical models, Monte Carlo (MC) simulations are more accurate in obtaining LETd distributions, but they are time-consuming. This study used the 3D LETd distributions of proton beam spots in water by MC simulations as a benchmark data set. Subsequently, by combining the water equivalent ratio of various human tissues, the 3D LETd distributions of clinical cases could be quickly obtained. Our method was applied to a single spot of 160 MeV proton beam in a water-bone phantom and a pelvic case. We also computed the 3D LETd distributions for multiple proton beam spots in the pelvic case and a lung case. The results of our method were compared with the results of MC simulations, demonstrating that our method can rapidly provide 3D LETd distributions of clinical cases with acceptable differences from MC simulations.
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Affiliation(s)
- Nan Yan
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chao Wu
- Medical Equipment Innovation Research Center, West China School of Medicine, Med+X Center for Manufacturing, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yun Zhou
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wentao Liao
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Junya Liu
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuehu Pu
- Medical Equipment Innovation Research Center, West China School of Medicine, Med+X Center for Manufacturing, West China Hospital, Sichuan University, Chengdu 610041, China
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10
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Gao Y, Chang CW, Pan S, Peng J, Ma C, Patel P, Roper J, Zhou J, Yang X. Deep learning-based synthetic dose-weighted LET map generation for intensity modulated proton therapy. Phys Med Biol 2024; 69:025004. [PMID: 38091613 PMCID: PMC10767225 DOI: 10.1088/1361-6560/ad154b] [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: 07/31/2023] [Revised: 12/02/2023] [Accepted: 12/13/2023] [Indexed: 01/06/2024]
Abstract
The advantage of proton therapy as compared to photon therapy stems from the Bragg peak effect, which allows protons to deposit most of their energy directly at the tumor while sparing healthy tissue. However, even with such benefits, proton therapy does present certain challenges. The biological effectiveness differences between protons and photons are not fully incorporated into clinical treatment planning processes. In current clinical practice, the relative biological effectiveness (RBE) between protons and photons is set as constant 1.1. Numerous studies have suggested that the RBE of protons can exhibit significant variability. Given these findings, there is a substantial interest in refining proton therapy treatment planning to better account for the variable RBE. Dose-average linear energy transfer (LETd) is a key physical parameter for evaluating the RBE of proton therapy and aids in optimizing proton treatment plans. Calculating precise LETddistributions necessitates the use of intricate physical models and the execution of specialized Monte-Carlo simulation software, which is a computationally intensive and time-consuming progress. In response to these challenges, we propose a deep learning based framework designed to predict the LETddistribution map using the dose distribution map. This approach aims to simplify the process and increase the speed of LETdmap generation in clinical settings. The proposed CycleGAN model has demonstrated superior performance over other GAN-based models. The mean absolute error (MAE), peak signal-to-noise ratio and normalized cross correlation of the LETdmaps generated by the proposed method are 0.096 ± 0.019 keVμm-1, 24.203 ± 2.683 dB, and 0.997 ± 0.002, respectively. The MAE of the proposed method in the clinical target volume, bladder, and rectum are 0.193 ± 0.103, 0.277 ± 0.112, and 0.211 ± 0.086 keVμm-1, respectively. The proposed framework has demonstrated the feasibility of generating synthetic LETdmaps from dose maps and has the potential to improve proton therapy planning by providing accurate LETdinformation.
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Affiliation(s)
- Yuan Gao
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, United States of America
| | - Chih-Wei Chang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, United States of America
| | - Shaoyan Pan
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, United States of America
- Department of Biomedical Informatics, Emory University, Atlanta, GA, United States of America
| | - Junbo Peng
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, United States of America
| | - Chaoqiong Ma
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, United States of America
| | - Pretesh Patel
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, United States of America
| | - Justin Roper
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, United States of America
| | - Jun Zhou
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, United States of America
| | - Xiaofeng Yang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, United States of America
- Department of Biomedical Informatics, Emory University, Atlanta, GA, United States of America
- Department of Nuclear & Radiological Engineering and Medical Physics, Georgia Institute of Technology, Atlanta, GA, United States of America
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11
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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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12
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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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13
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Edvardsson A, Gorgisyan J, Andersson KM, Vallhagen Dahlgren C, Dasu A, Gram D, Björk-Eriksson T, Munck af Rosenschöld P. Robustness and dosimetric verification of hippocampal-sparing craniospinal pencil beam scanning proton plans for pediatric medulloblastoma. Phys Imaging Radiat Oncol 2024; 29:100555. [PMID: 38405431 PMCID: PMC10891325 DOI: 10.1016/j.phro.2024.100555] [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: 10/16/2023] [Revised: 02/06/2024] [Accepted: 02/08/2024] [Indexed: 02/27/2024] Open
Abstract
Background and Purpose Hippocampal-sparing (HS) is a method that can potentially reduce late cognitive complications for pediatric medulloblastoma (MB) patients treated with craniospinal proton therapy (PT). The aim of this study was to investigate robustness and dosimetric plan verification of pencil beam scanning HS PT. Materials and Methods HS and non-HS PT plans for the whole brain part of craniospinal treatment were created for 15 pediatric MB patients. A robust evaluation of the plans was performed. Plans were recalculated in a water phantom and measured field-by-field using an ion chamber detector at depths corresponding to the central part of hippocampi. All HS and non-HS fields were measured with the standard resolution of the detector and in addition 16 HS fields were measured with high resolution. Measured and planned dose distributions were compared using gamma evaluation. Results The median mean hippocampus dose was reduced from 22.9 Gy (RBE) to 8.9 Gy (RBE), while keeping CTV V95% above 95 % for all nominal HS plans. HS plans were relatively robust regarding hippocampus mean dose, however, less robust regarding target coverage and maximum dose compared to non-HS plans. For standard resolution measurements, median pass rates were 99.7 % for HS and 99.5 % for non-HS plans (p < 0.001). For high-resolution measurements, median pass rates were 100 % in the hippocampus region and 98.2 % in the surrounding region. Conclusions A substantial reduction of dose in the hippocampus region appeared feasible. Dosimetric accuracy of HS plans was comparable to non-HS plans and agreed well with planned dose distribution in the hippocampus region.
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Affiliation(s)
- Anneli Edvardsson
- Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Sweden
- Medical Radiation Physics, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Jenny Gorgisyan
- Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Sweden
- Medical Radiation Physics, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | | | | | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Daniel Gram
- Department of Clinical Oncology and Palliative Care, Radiotherapy, Zealand University Hospital, Næstved, Denmark
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
- Department of Oncology – Section of Radiotherapy, Rigshospitalet, Copenhagen, Denmark
| | - Thomas Björk-Eriksson
- Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Regional Cancer Centre West, Western Sweden Healthcare Region, Gothenburg, Sweden
| | - Per Munck af Rosenschöld
- Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Sweden
- Medical Radiation Physics, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
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14
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Parisi A, Beltran CJ, Furutani KM. Variable RBE in proton radiotherapy: a comparative study with the predictive Mayo Clinic Florida microdosimetric kinetic model and phenomenological models of cell survival. Phys Med Biol 2023; 68:185020. [PMID: 38133518 DOI: 10.1088/1361-6560/acf43b] [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: 05/26/2023] [Accepted: 08/25/2023] [Indexed: 12/23/2023]
Abstract
Objectives. (1) To examine to what extent the cell- and exposure- specific information neglected in the phenomenological proton relative biological effectiveness (RBE) models could influence the computed RBE in proton therapy. (2) To explore similarities and differences in the formalism and the results between the linear energy transfer (LET)-based phenomenological proton RBE models and the microdosimetry-based Mayo Clinic Florida microdosimetric kinetic model (MCF MKM). (3) To investigate how the relationship between the RBE and the dose-mean proton LET is affected by the proton energy spectrum and the secondary fragments.Approach. We systematically compared six selected phenomenological proton RBE models with the MCF MKM in track-segment simulations, monoenergetic proton beams in a water phantom, and two spread-out Bragg peaks. A representative comparison within vitrodata for human glioblastoma cells (U87 cell line) is also included.Main results. Marked differences were observed between the results of the phenomenological proton RBE models, as reported in previous studies. The dispersion of these models' results was found to be comparable to the spread in the MCF MKM results obtained by varying the cell-specific parameters neglected in the phenomenological models. Furthermore, while single cell-specific correlation between RBE and the dose-mean proton LET seems reasonable above 2 keVμm-1, caution is necessary at lower LET values due to the relevant contribution of secondary fragments. The comparison within vitrodata demonstrates comparable agreement between the MCF MKM predictions and the results of the phenomenological models.Significance. The study highlights the importance of considering cell-specific characteristics and detailed radiation quality information for accurate RBE calculations in proton therapy. Furthermore, these results provide confidence in the use of the MCF MKM for clonogenic survival RBE calculations in proton therapy, offering a more mechanistic approach compared to phenomenological models.
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Affiliation(s)
- Alessio Parisi
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL, United States of America
| | - Chris J Beltran
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL, United States of America
| | - Keith M Furutani
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL, United States of America
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15
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Shepard C, Kanai Y. Ion-Type Dependence of DNA Electronic Excitation in Water under Proton, α-Particle, and Carbon Ion Irradiation: A First-Principles Simulation Study. J Phys Chem B 2023; 127:10700-10709. [PMID: 37943091 DOI: 10.1021/acs.jpcb.3c05446] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2023]
Abstract
Understanding how the electronic excitation of DNA changes in response to different high-energy particles is central to advancing ion beam cancer therapy and other related approaches, such as boron neutron capture therapy. While protons have been the predominant ions of choice in ion beam cancer therapy, heavier ions, particularly carbon ions, have drawn significant attention over the past decade. Carbon ions are expected to transfer larger amounts of energy according to linear response theory. However, molecular-level details of the electronic excitation under heavier ion irradiation remain unknown. In this work, we use real-time time-dependent density functional theory simulations to examine the quantum-mechanical details of DNA electronic excitations in water under proton, α-particle, and carbon ion irradiation. Our results show that the energy transfer does indeed increase for the heavier ions, while the excitation remains highly conformal. However, the increase in the energy transfer rate, measured by electronic stopping power, does not match the prediction by the linear response model, even when accounting for the velocity dependence of the irradiating ion's charge. The simulations also reveal that while the number of holes generated on DNA increases for heavier ions, the increase is only partially responsible for the larger stopping power. Larger numbers of highly energetic holes formed from the heavier ions also contribute significantly to the increased electronic stopping power.
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Affiliation(s)
- Christopher Shepard
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
| | - Yosuke Kanai
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
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16
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Kneepkens E, Wolfs C, Wanders RG, Traneus E, Eekers D, Verhaegen F. Shoot-through proton FLASH irradiation lowers linear energy transfer in organs at risk for neurological tumors and is robust against density variations. Phys Med Biol 2023; 68:215020. [PMID: 37820687 DOI: 10.1088/1361-6560/ad0280] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 10/11/2023] [Indexed: 10/13/2023]
Abstract
Objective. The goal of the study was to test the hypothesis that shoot-through FLASH proton beams would lead to lower dose-averaged LET (LETD) values in critical organs, while providing at least equal normal tissue sparing as clinical proton therapy plans.Approach. For five neurological tumor patients, pencil beam scanning (PBS) shoot-through plans were made, using the maximum energy of 227 MeV and assuming a hypothetical FLASH protective factor (FPF) of 1.5. The effect of different FPF ranging from 1.2 to 1.8 on the clinical goals were also considered. LETDwas calculated for the clinical plan and the shoot-through plan, applying a 2 Gy total dose threshold (RayStation 8 A/9B and 9A-IonRPG). Robust evaluation was performed considering density uncertainty (±3% throughout entire volume).Main results.Clinical plans showed large LETDvariations compared to shoot-through plans and the maximum LETDin OAR is 1.2-8 times lower for the latter. Although less conformal, shoot-through plans met the same clinical goals as the clinical plans, for FLASH protection factors above 1.4. The FLASH shoot-through plans were more robust to density uncertainties with a maximum OAR D2%increase of 0.6 Gy versus 5.7 Gy in the clinical plans.Significance.Shoot-through proton FLASH beams avoid uncertainties in LETDdistributions and proton range, provide adequate target coverage, meet planning constraints and are robust to density variations.
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Affiliation(s)
- Esther Kneepkens
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Cecile Wolfs
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Roel-Germ Wanders
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Erik Traneus
- RaySearch Laboratories AB, SE-103 65, Stockholm, Sweden
| | - Danielle Eekers
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Frank Verhaegen
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
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17
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Smulders B, Stolarczyk L, Seiersen K, Nørrevang O, Sommer Kristensen B, Schut DA, Thomsen K, Lassen-Ramshad Y, Høyer M, Muhic A, Vestergaard A. Prediction of dose-sparing by protons assessed by a knowledge-based planning tool in radiotherapy of brain tumours. Acta Oncol 2023; 62:1541-1545. [PMID: 37793798 DOI: 10.1080/0284186x.2023.2264482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 09/22/2023] [Indexed: 10/06/2023]
Affiliation(s)
- Bob Smulders
- Danish Centre for Particle Therapy (DCPT), Aarhus University Hospital, Aarhus, Denmark
- Department of Oncology, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Liliana Stolarczyk
- Danish Centre for Particle Therapy (DCPT), Aarhus University Hospital, Aarhus, Denmark
| | - Klaus Seiersen
- Danish Centre for Particle Therapy (DCPT), Aarhus University Hospital, Aarhus, Denmark
| | - Ole Nørrevang
- Danish Centre for Particle Therapy (DCPT), Aarhus University Hospital, Aarhus, Denmark
| | - Bente Sommer Kristensen
- Department of Oncology, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Deborah Anne Schut
- Department of Oncology, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Karsten Thomsen
- Department of Oncology, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Yasmin Lassen-Ramshad
- Danish Centre for Particle Therapy (DCPT), Aarhus University Hospital, Aarhus, Denmark
| | - Morten Høyer
- Danish Centre for Particle Therapy (DCPT), Aarhus University Hospital, Aarhus, Denmark
| | - Aida Muhic
- Danish Centre for Particle Therapy (DCPT), Aarhus University Hospital, Aarhus, Denmark
- Department of Oncology, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Anne Vestergaard
- Danish Centre for Particle Therapy (DCPT), Aarhus University Hospital, Aarhus, Denmark
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18
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Yang Y, Gergelis KR, Shen J, Afzal A, Mullikin TC, Gao RW, Aziz K, Shumway DA, Corbin KS, Liu W, Mutter RW. Study of linear energy transfer effect on rib fracture in breast patients receiving pencil-beamscanning proton therapy. ARXIV 2023:arXiv:2310.20527v1. [PMID: 37961731 PMCID: PMC10635309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Purpose To study the effect of proton linear energy transfer (LET) on rib fracture in breast cancer patients treated with pencil-beam scanning proton therapy (PBS) using a novel tool of dose-LET volume histogram (DLVH). Methods From a prospective registry of patients treated with post-mastectomy proton therapy to the chest wall and regional lymph nodes for breast cancer between 2015 and 2020, we retrospectively identified rib fracture cases detected after completing treatment. Contemporaneously treated control patients that did not develop rib fracture were matched to patients 2:1 considering prescription dose, boost location, reconstruction status, laterality, chest wall thickness, and treatment year.The DLVH index, V(d, l), defined as volume(V) of the structure with at least dose(d) and LET(l), was calculated. DLVH plots between the fracture and control group were compared. Conditional logistic regression (CLR) model was used to establish the relation of V(d, l) and the observed fracture at each combination of d and l. The p-value derived from CLR model shows the statistical difference between fracture patients and the matched control group. Using the 2D p-value map derived from CLR model, the DLVH features associated with the patient outcomes were extracted. Results Seven rib fracture patients were identified, and fourteen matched patients were selected for the control group. The median time from the completion of proton therapy to rib fracture diagnosis was 12 months (range 5 to 14 months). Two patients had grade 2 symptomatic rib fracture while the remaining 5 were grade 1 incidentally detected on imaging. The derived p-value map demonstrated larger V(0-36Gy[RBE], 4.0-5.0 keV/μm) in patients experiencing fracture (p<0.1). For example, the p value for V(30 Gy[RBE], 4.0 keV/um) was 0.069. Conclusions In breast cancer patients receiving PBS, a larger volume of chest wall receiving moderate dose and high LET may result in increased risk of rib fracture.
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Affiliation(s)
- Yunze Yang
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, USA
| | - Kimberly R Gergelis
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55905, USA
- Department of Radiation Oncology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Jiajian Shen
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, USA
| | - Arslan Afzal
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Trey C Mullikin
- Department of Radiation Oncology, Duke Cancer Institute, Durham, NC 27710
| | - Robert W Gao
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Khaled Aziz
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Dean A Shumway
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Kimberly S Corbin
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Wei Liu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, USA
| | - Robert W Mutter
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55905, USA
- Department of Pharmacology, Mayo Clinic, Rochester, MN 55905, USA
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19
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Bianchi A, Selva A, Rossignoli M, Pasquato F, Missiaggia M, La Tessa C, Scifoni E, Tommasino F, Conte V. Microdosimetric analysis of the radiation quality of two different proton beams in the distal edge of the depth-dose profile. RADIATION PROTECTION DOSIMETRY 2023; 199:1979-1983. [PMID: 37819318 DOI: 10.1093/rpd/ncac236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/20/2022] [Accepted: 10/21/2022] [Indexed: 10/13/2023]
Abstract
Proton-therapy exploits the advantageous depth-dose profile of protons to induce the highest damage to tumoral cells in the last millimetres of their range in sharp Bragg Peak. To cover the whole tumoral volume, beams of different energies are combined to create the Spread Out Bragg Peak (SOBP). In passive modulated beams, the energy spread is created with modulators in which the highest energy beam is degraded through different thicknesses of calibrated plastic materials. The highest energy is chosen depending on the deepest point that needs to be treated. This study aims to investigate differences in the radiation quality in the distal edge of SOBP beams with different initial energy and modulation techniques based on microdosimetric measurements with mini Tissue-Equivalent Proportional Counters. The beams investigated are the 62 MeV proton SOBP of the clinical facility of CATANA and the 148 MeV proton SOBP of the research beam line of the proton-therapy centre of Trento.
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Affiliation(s)
- A Bianchi
- INFN-Laboratori Nazionali di Legnaro, 35020 Legnaro, Italy
| | - A Selva
- INFN-Laboratori Nazionali di Legnaro, 35020 Legnaro, Italy
| | - M Rossignoli
- INFN-Laboratori Nazionali di Legnaro, 35020 Legnaro, Italy
| | - F Pasquato
- INFN-Laboratori Nazionali di Legnaro, 35020 Legnaro, Italy
| | - M Missiaggia
- University of Trento, Dipartimento di Fisica, 38123 Povo Trento, Italy
- Trento Institute of Fundamental Physics and Applications, 38123 Povo Trento, Italy
| | - C La Tessa
- University of Trento, Dipartimento di Fisica, 38123 Povo Trento, Italy
- Trento Institute of Fundamental Physics and Applications, 38123 Povo Trento, Italy
| | - E Scifoni
- Trento Institute of Fundamental Physics and Applications, 38123 Povo Trento, Italy
| | - F Tommasino
- University of Trento, Dipartimento di Fisica, 38123 Povo Trento, Italy
- Trento Institute of Fundamental Physics and Applications, 38123 Povo Trento, Italy
| | - V Conte
- INFN-Laboratori Nazionali di Legnaro, 35020 Legnaro, Italy
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20
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Alexander GS, Pollock AE, Arons D, Ferris MJ, Molitoris JK, Regine WF, Witek ME. Post-treatment PET/CT for p16-positive oropharynx cancer treated with definitive proton therapy. J Clin Imaging Sci 2023; 13:31. [PMID: 37810180 PMCID: PMC10559439 DOI: 10.25259/jcis_74_2023] [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: 07/19/2023] [Accepted: 09/07/2023] [Indexed: 10/10/2023] Open
Abstract
Objectives Given emerging data suggesting that uncertainty in the relative biologic effectiveness at the distal end of the Bragg peak results in increased mucosal injury in patients with oropharynx cancer receiving adjuvant proton therapy, we evaluated the results of post-treatment positron emission tomography-computed tomography (PET/CT) in patients with p16-positive oropharynx cancer (p16+OPC) treated with definitive intensity-modulated proton therapy (IMPT). Material and Methods A retrospective cohort study of patients with p16+OPC treated with definitive IMPT between 2016 and 2022 was performed at a single institution. Patients with PET/CT scans within 6 months following completion of IMPT were included in the study. Positive post-treatment scans were defined by a maximum standard uptake values (SUVmax) >4.0 or a <65% reduction in SUVmax in either the primary tumor or lymph node. The Fisher's exact test was used to evaluate factors associated with positive post-treatment PET/ CT values. Results Sixty-two patients were included for analysis. Median follow-up was 21 months (range: 3-71 months) with a median time to post-treatment PET/CT of 3 months (range: 2-6 months). Median post-treatment SUVmax of the primary disease and nodal disease was 0 (mean: 0.8, range: 0-7.7) and 0 (mean: 0.7, range: 0-9.5), respectively. Median post-treatment percent reduction in SUVmax for the primary site and lymph node was 100% (mean: 94%, range: 31.3-100%) and 100% (mean: 89%, range: 23-100%), respectively. Eleven patients had a positive post-treatment PET/CT with one biopsy-proven recurrence. Negative and positive predictive values (NPV and PPV) were 98% and 9.1%, respectively. There were no factors associated with positive post-treatment PET/CT. Conclusion Similar to patients treated with photon-based radiation therapy, post-treatment PET/CT has a high NPV for patients with p16+OPC treated with definitive proton therapy and should be used to guide patient management. Additional patients and more events are needed to confirm the PPV of a post-treatment PET/CT in this favorable patient cohort.
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Affiliation(s)
- Gregory S. Alexander
- Department of Radiation Oncology, University of Maryland, Baltimore, United States
| | - Ariel Eve Pollock
- Department of Radiation Oncology, University of Maryland, Baltimore, United States
| | - Danielle Arons
- School of Medicine, University of Maryland, Baltimore, United States
| | - Matthew J. Ferris
- Department of Radiation Oncology, University of Maryland, Baltimore, United States
| | - Jason K. Molitoris
- Department of Radiation Oncology, University of Maryland, Baltimore, United States
| | - William F. Regine
- Department of Radiation Oncology, University of Maryland, Baltimore, United States
| | - Matthew E. Witek
- Department of Radiation Medicine, Medstar Georgetown University Hospital, Washington, United States
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21
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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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22
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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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23
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DeCunha JM, Newpower M, Mohan R. GPU-accelerated calculation of proton microdosimetric spectra as a function of target size, proton energy, and bounding volume size. Phys Med Biol 2023; 68:165012. [PMID: 37429311 DOI: 10.1088/1361-6560/ace60a] [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: 09/08/2022] [Accepted: 07/10/2023] [Indexed: 07/12/2023]
Abstract
Objective.Shortcomings of dose-averaged linear energy transfer (LETD), the quantity which is most commonly used to quantify proton relative biological effectiveness, have long been recognized. Microdosimetric spectra may overcome the limitations of LETDbut are extremely computationally demanding to calculate. A systematic library of lineal energy spectra for monoenergetic protons could enable rapid determination of microdosimetric spectra in a clinical environment. The objective of this work was to calculate and validate such a library of lineal energy spectra.Approach. SuperTrack, a GPU-accelerated CUDA/C++ based application, was developed to superimpose tracks calculated using Geant4 onto targets of interest and to compute microdosimetric spectra. Lineal energy spectra of protons with energies from 0.1 to 100 MeV were determined in spherical targets of diameters from 1 nm to 10μm and in bounding voxels with side lengths of 5μm and 3 mm.Main results.Compared to an analogous Geant4-based application, SuperTrack is up to 3500 times more computationally efficient if each track is resampled 1000 times. Dose spectra of lineal energy and dose-mean lineal energy calculated with SuperTrack were consistent with values published in the literature and with comparison to a Geant4 simulation. Using SuperTrack, we developed the largest known library of proton microdosimetric spectra as a function of primary proton energy, target size, and bounding volume size.Significance. SuperTrack greatly increases the computational efficiency of the calculation of microdosimetric spectra. The elevated lineal energy observed in a 3 mm side length bounding volume suggests that lineal energy spectra determined experimentally or computed in small bounding volumes may not be representative of the lineal energy spectra in voxels of a dose calculation grid. The library of lineal energy spectra calculated in this work could be integrated with a treatment planning system for rapid determination of lineal energy spectra in patient geometries.
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Affiliation(s)
- Joseph M DeCunha
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America
- Medical Physics Program, The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, United States of America
| | - Mark Newpower
- University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States of America
| | - Radhe Mohan
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America
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24
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Handeland AH, Indelicato DJ, Fredrik Fjæra L, Ytre-Hauge KS, Pettersen HES, Muren LP, Lassen-Ramshad Y, Stokkevåg CH. Linear energy transfer-inclusive models of brainstem necrosis following proton therapy of paediatric ependymoma. Phys Imaging Radiat Oncol 2023; 27:100466. [PMID: 37457667 PMCID: PMC10345333 DOI: 10.1016/j.phro.2023.100466] [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: 02/17/2023] [Revised: 06/22/2023] [Accepted: 06/24/2023] [Indexed: 07/18/2023] Open
Abstract
Background and Purpose Radiation-induced brainstem necrosis after proton therapy is a severe toxicity with potential association to uncertainties in the proton relative biological effectiveness (RBE). A constant RBE of 1.1 is assumed clinically, but the RBE is known to vary with linear energy transfer (LET). LET-inclusive predictive models of toxicity may therefore be beneficial during proton treatment planning. Hence, we aimed to construct models describing the association between brainstem necrosis and LET in the brainstem. Materials and methods A matched case-control cohort (n = 28, 1:3 case-control ratio) of symptomatic brainstem necrosis was selected from 954 paediatric ependymoma brain tumour patients treated with passively scattered proton therapy. Dose-averaged LET (LETd) parameters in restricted volumes (L50%, L10% and L0.1cm3, the cumulative LETd) within high-dose thresholds were included in linear- and logistic regression normal tissue complication probability (NTCP) models. Results A 1 keV/µm increase in L10% to the brainstem volume receiving dose over 54 Gy(RBE) led to an increased brainstem necrosis risk [95% confidence interval] of 2.5 [0.0, 7.8] percentage points. The corresponding logistic regression model had area under the receiver operating characteristic curve (AUC) of 0.76, increasing to 0.84 with the anterior pons substructure as a second parameter. 19 [7, 350] patients with toxicity were required to associate the L10% (D > 54 Gy(RBE)) and brainstem necrosis with 80% statistical power. Conclusion The established models of brainstem necrosis illustrate a potential impact of high LET regions in patients receiving high doses to the brainstem, and thereby support LET mitigation during clinical treatment planning.
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Affiliation(s)
- Andreas H. Handeland
- 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
- Department of Medical Physics, Oslo University Hospital, Norway
| | | | | | - Ludvig P. Muren
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | | | - Camilla H. Stokkevåg
- 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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25
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Magrin G, Palmans H, Stock M, Georg D. State-of-the-art and potential of experimental microdosimetry in ion-beam therapy. Radiother Oncol 2023; 182:109586. [PMID: 36842667 DOI: 10.1016/j.radonc.2023.109586] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/16/2023] [Accepted: 02/17/2023] [Indexed: 02/28/2023]
Abstract
In radiotherapy, radiation-quality should be an expression of the biological and physical characteristics of ionizing radiation such as spatial distribution of ionization or energy deposition. Linear energy transfer (LET) and lineal energy (y) are two descriptors used to quantify the radiation quality. These two quantities are connected and exhibit similar features. In ion-beam therapy (IBT), lineal energy can be measured with microdosimeters, which are specifically designed to cope with the high fluence of particles in clinical beams, while the quantification of LET is generally based on calculations. In pre-clinical studies, microdosimetric spectra are used for the indirect determination of relative biological effectiveness (RBE), e.g., using the microdosimetric kinetic model (MKM) or biophysical response functions. In this context it is important to consider saturation effects, which occur when the highest values of y become less biologically relevant compared to the relative contribution they make to the physical dose. Recent clinical data suggests that local tumor control and normal tissue effects can be linked to macroscopic and microscopic dosimetry parameters. In particular, positive clinical outcomes have been correlated to the highest LET values in the density distribution, and there is no evident link to the saturation discussed above. A systematic collection of microdosimetric information in combination with clinical data in retrospective studies may clarify the role of radiation quality at the highest LET. In the clinical setting, microdosimetry is not widely used yet, despite its potential to be linked with LET by experimentally-determined y values. Through this connection, both play an important role in complex therapy techniques such as intensity modulated particle therapy (IMPT), LET-painting and multi-ion optimization. This review summarizes the current state of microdosimetry for IBT and its potential, as well as research and development needed to make experimental microdosimetry a mature procedure in a clinical context.
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Affiliation(s)
- Giulio Magrin
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
| | - Hugo Palmans
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria; National Physical Laboratory, Teddington, UK
| | - Markus Stock
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria; Karl Landsteiner Universität, Krems, Austria
| | - Dietmar Georg
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria; Medical University of Vienna, Austria.
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26
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Variable Relative Biological Effectiveness of Proton Therapy Increases PET-Visible Mucosal Injury in Head and Neck Cancer Patients. Int J Radiat Oncol Biol Phys 2023; 115:861-865. [PMID: 36368433 DOI: 10.1016/j.ijrobp.2022.10.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 10/17/2022] [Accepted: 10/23/2022] [Indexed: 11/09/2022]
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27
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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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28
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Witzmann K, Raschke F, Löck S, Wesemann T, Krause M, Linn J, Troost EGC. Unchanged perfusion in normal-appearing white and grey matter of glioma patients nine months after proton beam irradiation. Acta Oncol 2023; 62:141-149. [PMID: 36801809 DOI: 10.1080/0284186x.2023.2176254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Purpose: Radio(chemo)therapy is used as a standard treatment for glioma patients. The surrounding normal tissue is inevitably affected by the irradiation. The aim of this longitudinal study was to investigate perfusion alterations in the normal-appearing tissue after proton irradiation and assess the dose sensitivity of the normal tissue perfusion.Methods: In 14 glioma patients, a sub-cohort of a prospective clinical trial (NCT02824731), perfusion changes in normal-appearing white matter (WM), grey matter (GM) and subcortical GM structures, i.e. caudate nucleus, hippocampus, amygdala, putamen, pallidum and thalamus, were evaluated before treatment and at three-monthly intervals after proton beam irradiation. The relative cerebral blood volume (rCBV) was assessed with dynamic susceptibility contrast MRI and analysed as the percentage ratio between follow-up and baseline image (ΔrCBV). Radiation-induced alterations were evaluated using Wilcoxon signed rank test. Dose and time correlations were investigated with univariate and multivariate linear regression models.Results: No significant ΔrCBV changes were found in any normal-appearing WM and GM region after proton beam irradiation. A positive correlation with radiation dose was observed in the multivariate regression model applied to the combined ΔrCBV values of low (1-20 Gy), intermediate (21-40 Gy) and high (41-60 Gy) dose regions of GM (p < 0.001), while no time dependency was detected in any normal-appearing area.Conclusion: The perfusion in normal-appearing brain tissue remained unaltered after proton beam therapy. In further studies, a direct comparison with changes after photon therapy is recommended to confirm the different effect of proton therapy on the normal-appearing tissue.
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Affiliation(s)
- Katharina Witzmann
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, 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, Dresden, Germany
| | - Felix Raschke
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, 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, 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.,Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Tumor 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
| | - Tim Wesemann
- Institute of Neuroradiology, University Hospital Carl Gustav Carus and Medical Faculty of Technische Universität, Dresden, Germany
| | - Mechthild Krause
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, 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, Dresden, Germany.,Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Tumor 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
| | - Jennifer Linn
- National Center for Tumor 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.,Institute of Neuroradiology, University Hospital Carl Gustav Carus and Medical Faculty of Technische Universität, Dresden, Germany
| | - Esther G C Troost
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, 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, Dresden, Germany.,Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Tumor 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
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Bianchi A, Selva A, Reniers B, Vanhavere F, Conte V. TOPAS simulations of the response of a mini-TEPC: benchmark with experimental data. Phys Med Biol 2023; 68. [PMID: 36595254 DOI: 10.1088/1361-6560/acabfe] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022]
Abstract
Objective. Microdosimetry offers a fast tool for radiation quality (RQ) verification to be implemented in treatment planning systems in proton therapy based on variable LET or RBE to move forward from the use of a fixed RBE of 1.1. It is known that the RBE of protons can increase up to 50% higher than that value in the last few millimetres of their range. Microdosimetry can be performed both experimentally and by means of Monte Carlo (MC) simulations. This paper has the aim of comparing the two approaches.Approach. Experimental measurements have been performed using a miniaturized Tissue equivalent proportional counter developed at the Legnaro National Laboratories of the Italian National Institute for Nuclear Physics with the aim of being used as RQ monitors for high intensity beams. MC simulations have been performed using the microdosimetric extension of TOPAS which provides optimized parameters and scorers for this application.Main results. Simulations were compared with experimental microdosimetric spectra in terms of shape of the spectra and their average values. Moreover, the latter have been investigated as possible estimators of LET obtained with the same MC code. The shape of the spectra is in general consistent with the experimental distributions and the average values of the distributions in both cases can predict the RQ increase with depth.Significance. This study aims at the comparison of microdosimetric spectra obtained from both experimental measurements and the microdosimetric extension of TOPAS in the same radiation field.
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Affiliation(s)
- Anna Bianchi
- INFN Laboratori Nazionali di Legnaro, viale dell'Università 2, I-35020 Legnaro, Italy
| | - Anna Selva
- INFN Laboratori Nazionali di Legnaro, viale dell'Università 2, I-35020 Legnaro, Italy
| | - Brigitte Reniers
- UHasselt, Faculty of Engineering Technology, Centre for Environmental Sciences, Nuclear Technology Center, Agoralaan 3590 Diepenbeek, Belgium
| | - Filip Vanhavere
- Belgian Nuclear Research Centre, SCK CEN, Boeretang 200, 2400 Mol, Belgium
| | - Valeria Conte
- INFN Laboratori Nazionali di Legnaro, viale dell'Università 2, I-35020 Legnaro, Italy
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Kalholm F, Grzanka L, Toma-Dasu I, Bassler N. Modeling RBE with other quantities than LET significantly improves prediction of in vitro cell survival for proton therapy. Med Phys 2023; 50:651-659. [PMID: 36321465 PMCID: PMC10134779 DOI: 10.1002/mp.16029] [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: 02/19/2022] [Revised: 08/17/2022] [Accepted: 08/31/2022] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND For proton therapy, a relative biological effectiveness (RBE) of 1.1 has broadly been applied clinically. However, as unexpected toxicities have been observed by the end of the proton tracks, variable RBE models have been proposed. Typically, the dose-averaged linear energy transfer (LETd ) has been used as an input variable for these models but the way the LETd was defined, calculated, or determined was not always consistent, potentially impacting the corresponding RBE value. PURPOSE This study compares consistently calculated LETd with other quantities as input variables for a phenomenological RBE model and attempts to determine which quantity that can best predicts proton RBE. The comparison was performed within the frame of introducing a new model for the proton RBE. METHODS High-throughput experimental setups of in vitro cell survival studies for proton RBE determination are simulated using the SHIELD-HIT12A Monte Carlo particle transport code. Together with LET, z ∗ 2 / β 2 $z^{*2}/\beta ^2$ , here called effective Q (Qeff ), and Q are scored. Each quantity is calculated using the dose and track averaging methods, because the scoring includes all hadronic particles, all protons or only primaries. A phenomenological linear-quadratic-based RBE model is subsequently applied to the in vitro data with the various beam quality descriptors used as input variables and the goodness of fit is determined and compared using a bootstrapping approach. Both linear and nonlinear fit functions were tested. RESULTS Versions of Qeff and Q outperform LET with a statistically significant margin, with the best nonlinear and linear fit having a relative root mean square error (RMSE) for RBE2Gy ± one standard error of 1.55 ± 0.04 (Qeff, t, primary ) and 2.84 ± 0.07 (Qeff, d, primary ), respectively. For comparison, the corresponding best nonlinear and linear fits for LETd, all protons had a relative RMSE of 2.07 ± 0.06 and 3.39 ± 0.08, respectively. Applying Welch's t-test for comparing the calculated RMSE of RBE2Gy resulted in two-tailed p-values of <0.002 for all Q and Qeff quantities compared to LETd, all protons . CONCLUSIONS The study shows that Q or Qeff could be better RBE descriptors that dose averaged LET.
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Affiliation(s)
- Fredrik Kalholm
- Medical Radiation Physics, Department of Physics, Stockholm University, Stockholm, Sweden.,Department of Oncology and Pathology, Medical Radiation Physics, Karolinska Institutet, Stockholm, Sweden
| | - Leszek Grzanka
- Institute of Nuclear Physics Polish Academy of Sciences, Krakow, Poland
| | - Iuliana Toma-Dasu
- Medical Radiation Physics, Department of Physics, Stockholm University, Stockholm, Sweden.,Department of Oncology and Pathology, Medical Radiation Physics, Karolinska Institutet, Stockholm, Sweden
| | - Niels Bassler
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
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31
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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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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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Mori Y, Okonogi N, Matsumoto S, Furuichi W, Fukahori M, Miyasaka Y, Murata K, Wakatsuki M, Imai R, Koto M, Yamada S, Ishikawa H, Kanematsu N, Tsuji H. Effects of dose and dose-averaged linear energy transfer on pelvic insufficiency fractures after carbon-ion radiotherapy for uterine carcinoma. Radiother Oncol 2022; 177:33-39. [PMID: 36252637 DOI: 10.1016/j.radonc.2022.10.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 10/07/2022] [Accepted: 10/11/2022] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND PURPOSE The correlation between dose-averaged linear energy transfer (LETd) and its therapeutic or adverse effects, especially in carbon-ion radiotherapy (CIRT), remains controversial. This study aimed to investigate the effects of LETd and dose on pelvic insufficiency fractures after CIRT. MATERIAL AND METHODS Among patients who underwent CIRT for uterine carcinoma, 101 who were followed up for > 6 months without any other therapy were retrospectively analyzed. The sacrum insufficiency fractures (SIFs) were graded according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer toxicity criteria. The correlations between the relative biological effectiveness (RBE)-weighted dose, LETd, physical dose, clinical factors, and SIFs were evaluated. In addition, we analyzed the association of SIF with LETd, physical dose, and clinical factors in cases where the sacrum D50% RBE-weighted dose was above the median dose. RESULTS At the last follow-up, 19 patients developed SIFs. Receiver operating characteristic curve analysis revealed that the sacrum D50% RBE-weighted dose was a valuable predictor of SIF. Univariate analyses suggested that LETd V10 keV/µm, physical dose V5 Gy, and smoking status were associated with SIF. Cox regression analysis in patients over 50 years of age validated that current smoking habit was the sole risk factor for SIF. Therefore, LETd or physical dose parameters were not associated with SIF prediction. CONCLUSION The sacrum D50% RBE-weighted dose was identified as a risk factor for SIF. Additionally, neither LETd nor physical dose parameters were associated with SIF prediction.
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Affiliation(s)
- Yasumasa Mori
- QST Hospital, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; Department of Radiation Oncology, Gunma University Graduate School of Medicine, 3-39-15, Showa-machi, Maebashi, Gunma 371-8511, Japan.
| | - Noriyuki Okonogi
- QST Hospital, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
| | - Shinnosuke Matsumoto
- Department of Accelerator and Medical Physics, National Institutes for Quantum Science and Technology.
| | - Wataru Furuichi
- Accelerator Engineering Corporation, 6-18-1-301 Konakadai, Inage-ku, Chiba 263-0043, Japan.
| | - Mai Fukahori
- Managing Unit, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
| | - Yuhei Miyasaka
- Department of Radiation Oncology, Gunma University Graduate School of Medicine, 3-39-15, Showa-machi, Maebashi, Gunma 371-8511, Japan.
| | - Kazutoshi Murata
- QST Hospital, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
| | - Masaru Wakatsuki
- QST Hospital, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
| | - Reiko Imai
- QST Hospital, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
| | - Masashi Koto
- QST Hospital, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
| | - Shigeru Yamada
- QST Hospital, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
| | - Hitoshi Ishikawa
- QST Hospital, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
| | - Nobuyuki Kanematsu
- Department of Accelerator and Medical Physics, National Institutes for Quantum Science and Technology.
| | - Hiroshi Tsuji
- QST Hospital, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
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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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Hahn C, Heuchel L, Ödén J, Traneus E, Wulff J, Plaude S, Timmermann B, Bäumer C, Lühr A. Comparing biological effectiveness guided plan optimization strategies for cranial proton therapy: potential and challenges. Radiat Oncol 2022; 17:169. [PMID: 36273132 DOI: 10.1186/s13014-022-02143-x] [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: 05/19/2022] [Accepted: 10/10/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To introduce and compare multiple biological effectiveness guided (BG) proton plan optimization strategies minimizing variable relative biological effectiveness (RBE) induced dose burden in organs at risk (OAR) while maintaining plan quality with a constant RBE. METHODS Dose-optimized (DOSEopt) proton pencil beam scanning reference treatment plans were generated for ten cranial patients with prescription doses ≥ 54 Gy(RBE) and ≥ 1 OAR close to the clinical target volume (CTV). For each patient, four additional BG plans were created. BG objectives minimized either proton track-ends, dose-averaged linear energy transfer (LETd), energy depositions from high-LET protons or variable RBE-weighted dose (DRBE) in adjacent serially structured OARs. Plan quality (RBE = 1.1) was assessed by CTV dose coverage and robustness (2 mm setup, 3.5% density), dose homogeneity and conformity in the planning target volumes and adherence to OAR tolerance doses. LETd, DRBE (Wedenberg model, α/βCTV = 10 Gy, α/βOAR = 2 Gy) and resulting normal tissue complication probabilities (NTCPs) for blindness and brainstem necrosis were derived. Differences between DOSEopt and BG optimized plans were assessed and statistically tested (Wilcoxon signed rank, α = 0.05). RESULTS All plans were clinically acceptable. DOSEopt and BG optimized plans were comparable in target volume coverage, homogeneity and conformity. For recalculated DRBE in all patients, all BG plans significantly reduced near-maximum DRBE to critical OARs with differences up to 8.2 Gy(RBE) (p < 0.05). Direct DRBE optimization primarily reduced absorbed dose in OARs (average ΔDmean = 2.0 Gy; average ΔLETd,mean = 0.1 keV/µm), while the other strategies reduced LETd (average ΔDmean < 0.3 Gy; average ΔLETd,mean = 0.5 keV/µm). LET-optimizing strategies were more robust against range and setup uncertaintes for high-dose CTVs than DRBE optimization. All BG strategies reduced NTCP for brainstem necrosis and blindness on average by 47% with average and maximum reductions of 5.4 and 18.4 percentage points, respectively. CONCLUSIONS All BG strategies reduced variable RBE-induced NTCPs to OARs. Reducing LETd in high-dose voxels may be favourable due to its adherence to current dose reporting and maintenance of clinical plan quality and the availability of reported LETd and dose levels from clinical toxicity reports after cranial proton therapy. These optimization strategies beyond dose may be a first step towards safely translating variable RBE optimization in the clinics.
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Affiliation(s)
- Christian Hahn
- Department of Physics, TU Dortmund University, Dortmund, 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, Dresden, Germany. .,Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
| | - Lena Heuchel
- Department of Physics, TU Dortmund University, Dortmund, Germany
| | - Jakob Ödén
- RaySearch Laboratories AB, Stockholm, Sweden
| | | | - Jörg Wulff
- West German Proton Therapy Centre Essen, Essen, Germany.,West German Cancer Center (WTZ), University Hospital Essen, Essen, Germany
| | - Sandija Plaude
- West German Proton Therapy Centre Essen, Essen, Germany.,West German Cancer Center (WTZ), University Hospital Essen, Essen, Germany
| | - Beate Timmermann
- West German Proton Therapy Centre 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), Heidelberg, Germany
| | - Christian Bäumer
- Department of Physics, TU Dortmund University, Dortmund, Germany.,West German Proton Therapy Centre Essen, Essen, Germany.,West German Cancer Center (WTZ), University Hospital Essen, Essen, Germany.,German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Armin Lühr
- Department of Physics, TU Dortmund University, Dortmund, Germany
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Bianchi A, Selva A, Rossignoli M, Pasquato F, Missiaggia M, Scifoni E, La Tessa C, Tommasino F, Conte V. Microdosimetry with a mini-TEPC in the spread-out Bragg peak of 148 MeV protons. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110567] [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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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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Parisi A, Beltran CJ, Furutani KM. The Mayo Clinic Florida microdosimetric kinetic model of clonogenic survival: formalism and first benchmark against in vitro and in silico data. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac7375] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/25/2022] [Indexed: 12/30/2022]
Abstract
Abstract
Objective. To develop a new model (Mayo Clinic Florida microdosimetric kinetic model, MCF MKM) capable of accurately describing the in vitro clonogenic survival at low and high linear energy transfer (LET) using single-event microdosimetric spectra in a single target. Methodology. The MCF MKM is based on the ‘post-processing average’ implementation of the non-Poisson microdosimetric kinetic model and includes a novel expression to compute the particle-specific quadratic-dependence of the cell survival with respect to dose (β of the linear-quadratic model). A new methodology to a priori calculate the mean radius of the MCF MKM subnuclear domains is also introduced. Lineal energy spectra were simulated with the Particle and Heavy Ion Transport code System (PHITS) for 1H, 4He, 12C, 20Ne, 40Ar, 56Fe, and 132Xe ions and used in combination with the MCF MKM to calculate the ion-specific LET-dependence of the relative biological effectiveness (RBE) for Chinese hamster lung fibroblasts (V79 cell line) and human salivary gland tumor cells (HSG cell line). The results were compared with in vitro data from the Particle Irradiation Data Ensemble (PIDE) and in silico results of different models. The possibility of performing experiment-specific predictions to explain the scatter in the in vitro RBE data was also investigated. Finally, a sensitivity analysis on the model parameters is also included. Main results. The RBE values predicted with the MCF MKM were found to be in good agreement with the in vitro data for all tested conditions. Though all MCF MKM model parameters were determined a priori, the accuracy of the MCF MKM was found to be comparable or superior to that of other models. The model parameters determined a priori were in good agreement with the ones obtained by fitting all available in vitro data. Significance. The MCF MKM will be considered for implementation in cancer radiotherapy treatment planning with accelerated ions.
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A systematic review of clinical studies on variable proton Relative Biological Effectiveness (RBE). Radiother Oncol 2022; 175:79-92. [PMID: 35988776 DOI: 10.1016/j.radonc.2022.08.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 08/05/2022] [Accepted: 08/12/2022] [Indexed: 11/21/2022]
Abstract
Recently, a number of clinical studies have explored links between possible Relative Biological Effectiveness (RBE) elevations and patient toxicities and/or image changes following proton therapy. Our objective was to perform a systematic review of such studies. We applied a "Problem [RBE], Intervention [Protons], Population [Patients], Outcome [Side effect]" search strategy to the PubMed database. From our search, we retrieved studies which: (a) performed novel voxel-wise analyses of patient effects versus physical dose and LET (n = 13), and (b) compared image changes between proton and photon cohorts with regard to proton RBE (n = 9). For each retrieved study, we extracted data regarding: primary tumour type; size of patient cohort; type of image change studied; image-registration method (deformable or rigid); LET calculation method, and statistical methodology. We compared and contrasted their methods in order to discuss the weight of clinical evidence for variable proton RBE. We concluded that clinical evidence for variable proton RBE remains statistically weak at present. Our principal recommendation is that proton centres and clinical trial teams collaborate to standardize follow-up protocols and statistical analysis methods, so that larger patient cohorts can ultimately be considered for RBE analyses.
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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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Frame CM, Chen Y, Gagnon J, Yuan Y, Ma T, Dritschilo A, Pang D. Proton induced DNA double strand breaks at the Bragg peak: Evidence of enhanced LET effect. Front Oncol 2022; 12:930393. [PMID: 35992825 PMCID: PMC9388940 DOI: 10.3389/fonc.2022.930393] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 07/18/2022] [Indexed: 11/13/2022] Open
Abstract
PurposeTo investigate DNA double strand breaks (DSBs) induced by therapeutic proton beams in plateau and Bragg peak to demonstrate DSB induction due to the higher LET in the Bragg peak.Materials and MethodspUC19 plasmid DNA samples were irradiated to doses of 1000 and 3000 Gy on a Mevion S250i proton system with a monoenergetic, 110 MeV, proton beam at depths of 2 and 9.4 cm, corresponding to a position on the plateau and distal Bragg peak of the beam, respectively. The irradiated DNA samples were imaged by atomic force microscopy for visualization of individual DNA molecules, either broken or intact, and quantification of the DNA fragment length distributions for each of the irradiated samples. Percentage of the broken DNA and average number of DSBs per DNA molecule were obtained.ResultsCompared to irradiation effects in the plateau region, DNA irradiated at the Bragg peak sustained more breakage at the same dose, yielding more short DNA fragments and higher numbers of DSB per DNA molecule.ConclusionThe higher LET of proton beams at the Bragg peak results in more densely distributed DNA DSBs, which supports an underlying mechanism for the increased cell killing by protons at the Bragg peak.
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MD JKB, Amer A, Khose S, Flint D, Adair A, Yepes P, Grosshans D, Johnson J, Chung C. Brain Radionecrosis Outside the Target Volume after Proton Radiotherapy: Analyses of Multiparametric Imaging and Proton Biological Effectiveness. Adv Radiat Oncol 2022; 7:101044. [DOI: 10.1016/j.adro.2022.101044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 07/27/2022] [Indexed: 11/17/2022] Open
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A case-control study of linear energy transfer and relative biological effectiveness related to symptomatic brainstem toxicity following pediatric proton therapy. Radiother Oncol 2022; 175:47-55. [PMID: 35917900 DOI: 10.1016/j.radonc.2022.07.022] [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: 04/07/2022] [Revised: 06/28/2022] [Accepted: 07/25/2022] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND PURPOSE A fixed relative biological effectiveness (RBE) of 1.1 (RBE1.1) is used clinically in proton therapy even though the RBE varies with properties such as dose level and linear energy transfer (LET). We therefore investigated if symptomatic brainstem toxicity in pediatric brain tumor patients treated with proton therapy could be associated with a variable LET and RBE. MATERIALS AND METHODS 36 patients treated with passive scattering proton therapy were selected for a case-control study from a cohort of 954 pediatric brain tumor patients. Nine children with symptomatic brainstem toxicity were each matched to three controls based on age, diagnosis, adjuvant therapy, and brainstem RBE1.1 dose characteristics. Differences across cases and controls related to the dose-averaged LET (LETd) and variable RBE-weighted dose from two RBE models were analyzed in the high-dose region. RESULTS LETd metrics were marginally higher for cases vs. controls for the majority of dose levels and brainstem substructures. Considering areas with doses above 54 Gy(RBE1.1), we found a moderate trend of 13% higher median LETd in the brainstem for cases compared to controls (P = .08), while the difference in the median variable RBE-weighted dose for the same structure was only 2% (P = .6). CONCLUSION Trends towards higher LETd for cases compared to controls were noticeable across structures and LETd metrics for this patient cohort. While case-control differences were minor, an association with the observed symptomatic brainstem toxicity cannot be ruled out.
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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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Tian L, Hahn C, Lühr A. An ion-independent phenomenological relative biological effectiveness (RBE) model for proton therapy. Radiother Oncol 2022; 174:69-76. [PMID: 35803365 DOI: 10.1016/j.radonc.2022.06.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 06/14/2022] [Accepted: 06/28/2022] [Indexed: 11/17/2022]
Abstract
BACKGROUND A relative biological effectiveness (RBE) of 1.1 is used for proton therapy though clinical evidence of varying RBE was raised. Clinical studies on RBE variability have been conducted for decades for carbon radiation, which could advance the understanding of the clinical proton RBE given an ion-independent RBE model. In this work, such a model, linear and simple, using the beam quantity Q = Z2/E (Z = ion charge, E = kinetic energy per nucleon) was tested and compared to the commonly used, proton-specific and linear energy transfer (LET) based Wedenberg RBE model. MATERIAL AND METHODS The Wedenberg and Q models, both predicting RBEmax and RBEmin (i.e., RBE at vanishing and very high dose, respectively), are compared in terms of ion-dependence and prediction power. An experimental in-vitro data ensemble covering 115 publications for various ions was used as dataset. RESULTS The model parameter of the Q model was observed to be similar for different ions (in contrast to LET). The Q model was trained without any prior knowledge of proton data. For proton RBE, the differences between experimental data and corresponding predictions of the Wedenberg or the Q model were highly comparable. CONCLUSIONS A simple linear RBE model using Q instead of LET was proposed and tested to be able to predict proton RBE using model parameter trained based on only RBE data of other particles in a clinical proton energy range for a large in-vitro dataset. Adding (pre)clinical knowledge from carbon ion therapy may, therefore, reduce the dominating biological uncertainty in proton RBE modelling. This would translate in reduced RBE related uncertainty in proton therapy treatment planning.
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Affiliation(s)
- Liheng Tian
- TU Dortmund University, Department of Physics, Dortmund, Germany.
| | - Christian Hahn
- TU Dortmund University, Department of Physics, Dortmund, 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, Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Armin Lühr
- TU Dortmund University, Department of Physics, Dortmund, Germany.
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A novel method to assess the incident angle and the LET of protons using a compact single-layer timepix detector. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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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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Parisi A, Furutani KM, Beltran CJ. On the calculation of the relative biological effectiveness of ion radiation therapy using a biological weighting function, the microdosimetric kinetic model (MKM) and subsequent corrections (non-Poisson MKM and modified MKM). Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac5fdf] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 03/22/2022] [Indexed: 12/31/2022]
Abstract
Abstract
Objective. To investigate similarities and differences in the formalism, processing, and the results of relative biological effectiveness (RBE) calculations with a biological weighting function (BWF), the microdosimetric kinetic model (MKM) and subsequent modifications (non-Poisson MKM, modified MKM). This includes: (a) the extension of the V79-RBE10% BWF to model the RBE for other clonogenic survival levels; (b) a novel implementation of MKMs as weighting functions; (c) a benchmark against Chinese Hamster lung fibroblast (V79) in vitro data; (d) a study on the effect of pre- or post- processing the average biophysical quantities used for the RBE calculations; (e) a possible modification of the modified MKM parameters to improve the model accuracy at high linear energy transfer (LET). Methodology. Lineal energy spectra were simulated for two spherical targets (diameter = 0.464 or 1.0 μm) using PHITS for 1H, 4He, 12C, 20Ne, 40Ar, 56Fe and 132Xe ions. The results of the in silico calculations were compared with published in vitro data. Main results. All models appear to underestimate the RBE
α
of hydrogen ions. All MKMs generally overestimate the RBE50%, RBE10% and RBE1% for ions with an LET greater than ∼200 keV μm−1. This overestimation is greater for small surviving fractions and is likely due to the assumption of a radiation-independent quadratic term of clonogenic survival (ß). The overall RBE trends seem to be best described by the novel ‘post-processing average’ implementation of the non-Poisson MKM. In case of calculations with the non-Poisson MKM, pre- or post- processing the average biophysical quantities affects the computed RBE values significantly. Significance. This study presents a systematic analysis of the formalism and results of widely used microdosimetric models of clonogenic survival for ions relevant for cancer particle therapy and space radiation protection. Points for improvements were highlighted and will contribute to the development of upgraded biophysical models.
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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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