1
|
Lyngholm E, Stokkevåg CH, Lühr A, Tian L, Meric I, Tjelta J, Henjum H, Handeland AH, Ytre-Hauge KS. An updated variable RBE model for proton therapy. Phys Med Biol 2024; 69:125025. [PMID: 38527373 DOI: 10.1088/1361-6560/ad3796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 03/25/2024] [Indexed: 03/27/2024]
Abstract
Objective.While a constant relative biological effectiveness (RBE) of 1.1 forms the basis for clinical proton therapy, variable RBE models are increasingly being used in plan evaluation. However, there is substantial variation across RBE models, and several newin vitrodatasets have not yet been included in the existing models. In this study, an updatedin vitroproton RBE database was collected and used to examine current RBE model assumptions, and to propose an up-to-date RBE model as a tool for evaluating RBE effects in clinical settings.Approach.A proton database (471 data points) was collected from the literature, almost twice the size of the previously largest model database. Each data point included linear-quadratic model parameters and linear energy transfer (LET). Statistical analyses were performed to test the validity of commonly applied assumptions of phenomenological RBE models, and new model functions were proposed forRBEmaxandRBEmin(RBE at the lower and upper dose limits). Previously published models were refitted to the database and compared to the new model in terms of model performance and RBE estimates.Main results.The statistical analysis indicated that the intercept of theRBEmaxfunction should be a free fitting parameter and RBE estimates were clearly higher for models with free intercept.RBEminincreased with increasing LET, while a dependency ofRBEminon the reference radiation fractionation sensitivity (α/βx) did not significantly improve model performance. Evaluating the models, the new model gave overall lowest RMSE and highest R2 score. RBE estimates in the distal part of a spread-out-Bragg-peak in water (α/βx= 2.1 Gy) were 1.24-1.51 for original models, 1.25-1.49 for refits and 1.42 for the new model.Significance.An updated RBE model based on the currently largest database among published phenomenological models was proposed. Overall, the new model showed better performance compared to refitted published RBE models.
Collapse
Affiliation(s)
- Erlend Lyngholm
- Department of Physics and Technology, University of Bergen, Bergen, Norway
| | - Camilla Hanquist Stokkevåg
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| | - Armin Lühr
- Department of Physics, TU Dortmund University, Dortmund, Germany
| | - Liheng Tian
- Department of Physics, TU Dortmund University, Dortmund, Germany
| | - Ilker Meric
- Department of Computer Science, Electrical Engineering and Mathematical Sciences, Western Norway University of Applied Sciences, Bergen, Norway
| | - Johannes Tjelta
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| | - Helge Henjum
- Department of Physics and Technology, University of Bergen, Bergen, Norway
| | - Andreas Havsgård Handeland
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| | | |
Collapse
|
2
|
Kaulfers T, Lattery G, Cheng C, Zhao X, Selvaraj B, Wu H, Chhabra AM, Choi JI, Lin H, Simone CB, Hasan S, Kang M, Chang J. Pencil Beam Scanning Proton Bragg Peak Conformal FLASH in Prostate Cancer Stereotactic Body Radiotherapy. Cancers (Basel) 2024; 16:798. [PMID: 38398188 PMCID: PMC10886659 DOI: 10.3390/cancers16040798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/29/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024] Open
Abstract
Bragg peak FLASH radiotherapy (RT) uses a distal tracking method to eliminate exit doses and can achieve superior OAR sparing. This study explores the application of this novel method in stereotactic body radiotherapy prostate FLASH-RT. An in-house platform was developed to enable intensity-modulated proton therapy (IMPT) planning using a single-energy Bragg peak distal tracking method. The patients involved in the study were previously treated with proton stereotactic body radiotherapy (SBRT) using the pencil beam scanning (PBS) technique to 40 Gy in five fractions. FLASH plans were optimized using a four-beam arrangement to generate a dose distribution similar to the conventional opposing beams. All of the beams had a small angle of two degrees from the lateral direction to increase the dosimetry quality. Dose metrics were compared between the conventional PBS and the Bragg peak FLASH plans. The dose rate histogram (DRVH) and FLASH metrics of 40 Gy/s coverage (V40Gy/s) were investigated for the Bragg peak plans. There was no significant difference between the clinical and Bragg peak plans in rectum, bladder, femur heads, large bowel, and penile bulb dose metrics, except for Dmax. For the CTV, the FLASH plans resulted in a higher Dmax than the clinical plans (116.9% vs. 103.3%). For the rectum, the V40Gy/s reached 94% and 93% for 1 Gy dose thresholds in composite and single-field evaluations, respectively. Additionally, the FLASH ratio reached close to 100% after the application of the 5 Gy threshold in composite dose rate assessment. In conclusion, the Bragg peak distal tracking method can yield comparable plan quality in most OARs while preserving sufficient FLASH dose rate coverage, demonstrating that the ultra-high dose technique can be applied in prostate FLASH SBRT.
Collapse
Affiliation(s)
- Tyler Kaulfers
- Department of Physics and Astronomy, Hofstra University, Hempstead, NY 11549, USA; (T.K.); (G.L.)
| | - Grant Lattery
- Department of Physics and Astronomy, Hofstra University, Hempstead, NY 11549, USA; (T.K.); (G.L.)
| | - Chingyun Cheng
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA;
| | - Xingyi Zhao
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (X.Z.); (B.S.); (A.M.C.); (J.I.C.); (H.L.); (S.H.)
| | - Balaji Selvaraj
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (X.Z.); (B.S.); (A.M.C.); (J.I.C.); (H.L.); (S.H.)
| | - Hui Wu
- Department of Radiation Oncology, The Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou 450008, China;
| | - Arpit M. Chhabra
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (X.Z.); (B.S.); (A.M.C.); (J.I.C.); (H.L.); (S.H.)
| | - Jehee Isabelle Choi
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (X.Z.); (B.S.); (A.M.C.); (J.I.C.); (H.L.); (S.H.)
| | - Haibo Lin
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (X.Z.); (B.S.); (A.M.C.); (J.I.C.); (H.L.); (S.H.)
| | - Charles B. Simone
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (X.Z.); (B.S.); (A.M.C.); (J.I.C.); (H.L.); (S.H.)
| | - Shaakir Hasan
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (X.Z.); (B.S.); (A.M.C.); (J.I.C.); (H.L.); (S.H.)
| | - Minglei Kang
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (X.Z.); (B.S.); (A.M.C.); (J.I.C.); (H.L.); (S.H.)
| | - Jenghwa Chang
- Department of Physics and Astronomy, Hofstra University, Hempstead, NY 11549, USA; (T.K.); (G.L.)
- Northwell, 2000 Marcus Ave, Suite 300, New Hyde Park, NY 11042, USA
| |
Collapse
|
3
|
Schulte R, Johnstone C, Boucher S, Esarey E, Geddes CGR, Kravchenko M, Kutsaev S, Loo BW, Méot F, Mustapha B, Nakamura K, Nanni EA, Obst-Huebl L, Sampayan SE, Schroeder CB, Sheng K, Snijders AM, Snively E, Tantawi SG, Van Tilborg J. Transformative Technology for FLASH Radiation Therapy. APPLIED SCIENCES (BASEL, SWITZERLAND) 2023; 13:5021. [PMID: 38240007 PMCID: PMC10795821 DOI: 10.3390/app13085021] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/22/2024]
Abstract
The general concept of radiation therapy used in conventional cancer treatment is to increase the therapeutic index by creating a physical dose differential between tumors and normal tissues through precision dose targeting, image guidance, and radiation beams that deliver a radiation dose with high conformality, e.g., protons and ions. However, the treatment and cure are still limited by normal tissue radiation toxicity, with the corresponding side effects. A fundamentally different paradigm for increasing the therapeutic index of radiation therapy has emerged recently, supported by preclinical research, and based on the FLASH radiation effect. FLASH radiation therapy (FLASH-RT) is an ultra-high-dose-rate delivery of a therapeutic radiation dose within a fraction of a second. Experimental studies have shown that normal tissues seem to be universally spared at these high dose rates, whereas tumors are not. While dose delivery conditions to achieve a FLASH effect are not yet fully characterized, it is currently estimated that doses delivered in less than 200 ms produce normal-tissue-sparing effects, yet effectively kill tumor cells. Despite a great opportunity, there are many technical challenges for the accelerator community to create the required dose rates with novel compact accelerators to ensure the safe delivery of FLASH radiation beams.
Collapse
Affiliation(s)
- Reinhard Schulte
- Division of Biomedical Engineering Sciences, Loma Linda University, Loma Linda, CA 92350, USA
| | - Carol Johnstone
- Fermi National Accelerator Laboratory, Batavia, IL 60510, USA
| | - Salime Boucher
- RadiaBeam Technologies, LLC, Santa Monica, CA 90404, USA
| | - Eric Esarey
- Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | | | | | - Sergey Kutsaev
- RadiaBeam Technologies, LLC, Santa Monica, CA 90404, USA
| | - Billy W. Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - François Méot
- Brookhaven National Laboratory, Upton, NY 11973, USA
| | | | - Kei Nakamura
- Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Emilio A. Nanni
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | | | - Stephen E. Sampayan
- Lawrence Livermore National Laboratory, Livermore, CA 94551, USA
- Opcondys, Inc., Manteca, CA 95336, USA
| | | | - Ke Sheng
- Department of Radiation Oncology, University of California, San Francisco, CA 94115, USA
| | | | - Emma Snively
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Sami G. Tantawi
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | | |
Collapse
|
4
|
Daugherty EC, Mascia A, Zhang Y, Lee E, Xiao Z, Sertorio M, Woo J, McCann C, Russell K, Levine L, Sharma R, Khuntia D, Bradley J, Simone CB, Perentesis J, Breneman J. FLASH Radiotherapy for the Treatment of Symptomatic Bone Metastases (FAST-01): Protocol for the First Prospective Feasibility Study. JMIR Res Protoc 2023; 12:e41812. [PMID: 36206189 PMCID: PMC9893728 DOI: 10.2196/41812] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/29/2022] [Accepted: 10/04/2022] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND In preclinical studies, FLASH therapy, in which radiation delivered at ultrahigh dose rates of ≥40 Gy per second, has been shown to cause less injury to normal tissues than radiotherapy delivered at conventional dose rates. This paper describes the protocol for the first-in-human clinical investigation of proton FLASH therapy. OBJECTIVE FAST-01 is a prospective, single-center trial designed to assess the workflow feasibility, toxicity, and efficacy of FLASH therapy for the treatment of painful bone metastases in the extremities. METHODS Following informed consent, 10 subjects aged ≥18 years with up to 3 painful bone metastases in the extremities (excluding the feet, hands, and wrists) will be enrolled. A treatment field selected from a predefined library of plans with fixed field sizes (from 7.5 cm × 7.5 cm up to 7.5 cm × 20 cm) will be used for treatment. Subjects will receive 8 Gy of radiation in a single fraction-a well-established palliative regimen evaluated in prior investigations using conventional dose rate photon radiotherapy. A FLASH-enabled Varian ProBeam proton therapy unit will be used to deliver treatment to the target volume at a dose rate of ≥40 Gy per second, using the plateau (transmission) portion of the proton beam. After treatment, subjects will be assessed for pain response as well as any adverse effects of FLASH radiation. The primary end points include assessing the workflow feasibility and toxicity of FLASH treatment. The secondary end point is pain response at the treated site(s), as measured by patient-reported pain scores, the use of pain medication, and any flare in bone pain after treatment. The results will be compared to those reported historically for conventional dose rate photon radiotherapy, using the same radiation dose and fractionation. RESULTS FAST-01 opened to enrollment on November 3, 2020. Initial results are expected to be published in 2022. CONCLUSIONS The results of this investigation will contribute to further developing and optimizing the FLASH-enabled ProBeam proton therapy system workflow. The pain response and toxicity data acquired in our study will provide a greater understanding of FLASH treatment effects on tumor responses and normal tissue toxicities, and they will inform future FLASH trial designs. TRIAL REGISTRATION : ClinicalTrials.gov NCT04592887; http://clinicaltrials.gov/ct2/show/NCT04592887. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID) DERR1-10.2196/41812.
Collapse
Affiliation(s)
- Emily C Daugherty
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, OH, United States
| | - Anthony Mascia
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, OH, United States
- Cancer and Blood Disease Institute, Cincinnati Children's Hospital, Cincinnati, OH, United States
| | - Yong Zhang
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, OH, United States
- Cancer and Blood Disease Institute, Cincinnati Children's Hospital, Cincinnati, OH, United States
| | - Eunsin Lee
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, OH, United States
- Cancer and Blood Disease Institute, Cincinnati Children's Hospital, Cincinnati, OH, United States
| | - Zhiyan Xiao
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, OH, United States
- Cancer and Blood Disease Institute, Cincinnati Children's Hospital, Cincinnati, OH, United States
| | - Mathieu Sertorio
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, OH, United States
| | - Jennifer Woo
- Varian, A Siemens Healthineers Company, Palo Alto, CA, United States
| | - Claire McCann
- Varian, A Siemens Healthineers Company, Palo Alto, CA, United States
| | - Kenneth Russell
- Varian, A Siemens Healthineers Company, Palo Alto, CA, United States
| | - Lisa Levine
- Varian, A Siemens Healthineers Company, Palo Alto, CA, United States
| | - Ricky Sharma
- Varian, A Siemens Healthineers Company, Palo Alto, CA, United States
| | - Deepak Khuntia
- Varian, A Siemens Healthineers Company, Palo Alto, CA, United States
| | - Jeffrey Bradley
- Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA, United States
| | - Charles B Simone
- Department of Radiation Oncology, New York Proton Center, New York, NY, United States
| | - John Perentesis
- Cancer and Blood Disease Institute, Cincinnati Children's Hospital, Cincinnati, OH, United States
| | - John Breneman
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, OH, United States
| |
Collapse
|
5
|
Impact of DNA Repair Kinetics and Dose Rate on RBE Predictions in the UNIVERSE. Int J Mol Sci 2022; 23:ijms23116268. [PMID: 35682947 PMCID: PMC9181644 DOI: 10.3390/ijms23116268] [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: 04/13/2022] [Revised: 05/30/2022] [Accepted: 05/30/2022] [Indexed: 02/01/2023] Open
Abstract
Accurate knowledge of the relative biological effectiveness (RBE) and its dependencies is crucial to support modern ion beam therapy and its further development. However, the influence of different dose rates of the reference radiation and ion beam are rarely considered. The ion beam RBE-model within our "UNIfied and VERSatile bio response Engine" (UNIVERSE) is extended by including DNA damage repair kinetics to investigate the impact of dose-rate effects on the predicted RBE. It was found that dose-rate effects increase with dose and biological effects saturate at high dose-rates, which is consistent with data- and model-based studies in the literature. In a comparison with RBE measurements from a high dose in-vivo study, the predictions of the presented modification were found to be improved in comparison to the previous version of UNIVERSE and existing clinical approaches that disregard dose-rate effects. Consequently, DNA repair kinetics and the different dose rates applied by the reference and ion beams might need to be considered in biophysical models to accurately predict the RBE. Additionally, this study marks an important step in the further development of UNIVERSE, extending its capabilities in giving theoretical guidance to support progress in ion beam therapy.
Collapse
|
6
|
Guo Z, Buonanno M, Harken A, Zhou G, Hei TK. Mitochondrial Damage Response and Fate of Normal Cells Exposed to FLASH Irradiation with Protons. Radiat Res 2022; 197:569-582. [PMID: 35290449 DOI: 10.1667/rade-21-00181.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 02/24/2022] [Indexed: 11/03/2022]
Abstract
Radiation therapy (RT) plays an important role in cancer treatment. The clinical efficacy of radiation therapy is, however, limited by normal tissue toxicity in areas surrounding the irradiated tumor. Compared to conventional radiation therapy (CONV-RT) in which doses are typically delivered at dose rates between 0.03-0.05 Gy/s, there is evidence that radiation delivered at dose rates of orders of magnitude higher (known as FLASH-RT), dramatically reduces the adverse side effects in normal tissues while achieving similar tumor control. The present study focused on normal cell response and tested the hypothesis that proton-FLASH irradiation preserves mitochondria function of normal cells through the induction of phosphorylated Drp1. Normal human lung fibroblasts (IMR90) were irradiated under ambient oxygen concentration (21%) with protons (LET = 10 keV/μm) delivered at dose rates of either 0.33 Gy/s or 100 Gy/s. Mitochondrial dynamics, functions, cell growth and changes in protein expression levels were investigated. Compared to lower dose-rate proton irradiation, FLASH-RT prevented mitochondria damage characterized by morphological changes, functional changes (membrane potential, mtDNA copy number and oxidative enzyme levels) and oxyradical production. After CONV-RT, the phosphorylated form of Dynamin-1-like protein (p-Drp1) underwent dephosphorylation and aggregated into the mitochondria resulting in mitochondria fission and subsequent cell death. In contrast, p-Drp1 protein level did not significantly change after delivery of similar FLASH doses. Compared with CONV irradiation, FLASH irradiation using protons induces minimal mitochondria damage; our results highlight a possible contribution of Drp1-mediated mitochondrial homeostasis in this potential novel cancer treatment modality.
Collapse
Affiliation(s)
- Ziyang Guo
- Center for Radiological Research, College of Physician and Surgeons, Columbia University Medical Center, New York, New York.,State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Institute of Space Life Sciences, Medical College of Soochow University, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, China.,Department of Ultrasound Medicine, Peking University First Hospital, Beijing, China
| | - Manuela Buonanno
- Center for Radiological Research, College of Physician and Surgeons, Columbia University Medical Center, New York, New York
| | - Andrew Harken
- Center for Radiological Research, College of Physician and Surgeons, Columbia University Medical Center, New York, New York
| | - Guangming Zhou
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Institute of Space Life Sciences, Medical College of Soochow University, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, China
| | - Tom K Hei
- Center for Radiological Research, College of Physician and Surgeons, Columbia University Medical Center, New York, New York
| |
Collapse
|
7
|
Sakata D, Suzuki M, Hirayama R, Abe Y, Muramatsu M, Sato S, Belov O, Kyriakou I, Emfietzoglou D, Guatelli S, Incerti S, Inaniwa T. Performance Evaluation for Repair of HSGc-C5 Carcinoma Cell Using Geant4-DNA. Cancers (Basel) 2021; 13:6046. [PMID: 34885155 PMCID: PMC8656964 DOI: 10.3390/cancers13236046] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/30/2021] [Accepted: 09/07/2021] [Indexed: 12/27/2022] Open
Abstract
Track-structure Monte Carlo simulations are useful tools to evaluate initial DNA damage induced by irradiation. In the previous study, we have developed a Gean4-DNA-based application to estimate the cell surviving fraction of V79 cells after irradiation, bridging the gap between the initial DNA damage and the DNA rejoining kinetics by means of the two-lesion kinetics (TLK) model. However, since the DNA repair performance depends on cell line, the same model parameters cannot be used for different cell lines. Thus, we extended the Geant4-DNA application with a TLK model for the evaluation of DNA damage repair performance in HSGc-C5 carcinoma cells which are typically used for evaluating proton/carbon radiation treatment effects. For this evaluation, we also performed experimental measurements for cell surviving fractions and DNA rejoining kinetics of the HSGc-C5 cells irradiated by 70 MeV protons at the cyclotron facility at the National Institutes for Quantum and Radiological Science and Technology (QST). Concerning fast- and slow-DNA rejoining, the TLK model parameters were adequately optimized with the simulated initial DNA damage. The optimized DNA rejoining speeds were reasonably agreed with the experimental DNA rejoining speeds. Using the optimized TLK model, the Geant4-DNA simulation is now able to predict cell survival and DNA-rejoining kinetics for HSGc-C5 cells.
Collapse
Affiliation(s)
- Dousatsu Sakata
- Department of Accelerator and Medical Physics, Institute for Quantum Medical Science, QST, Chiba 263-8555, Japan; (Y.A.); (M.M.); (S.S.); (T.I.)
| | - Masao Suzuki
- Department of Charged Particle Therapy Research, Institute for Quantum Medical Science, QST, Chiba 263-8555, Japan; (M.S.); (R.H.)
| | - Ryoichi Hirayama
- Department of Charged Particle Therapy Research, Institute for Quantum Medical Science, QST, Chiba 263-8555, Japan; (M.S.); (R.H.)
| | - Yasushi Abe
- Department of Accelerator and Medical Physics, Institute for Quantum Medical Science, QST, Chiba 263-8555, Japan; (Y.A.); (M.M.); (S.S.); (T.I.)
| | - Masayuki Muramatsu
- Department of Accelerator and Medical Physics, Institute for Quantum Medical Science, QST, Chiba 263-8555, Japan; (Y.A.); (M.M.); (S.S.); (T.I.)
| | - Shinji Sato
- Department of Accelerator and Medical Physics, Institute for Quantum Medical Science, QST, Chiba 263-8555, Japan; (Y.A.); (M.M.); (S.S.); (T.I.)
| | - Oleg Belov
- Veksler and Baldin Laboratory of High Energy Physics, Joint Institute for Nuclear Research, 141980 Dubna, Russia;
- Institute of System Analysis and Management, Dubna State University, 141980 Dubna, Russia
| | - Ioanna Kyriakou
- Medical Physics Laboratory, Medical School, University of Ioannina, 45110 Ioannina, Greece; (I.K.); (D.E.)
| | - Dimitris Emfietzoglou
- Medical Physics Laboratory, Medical School, University of Ioannina, 45110 Ioannina, Greece; (I.K.); (D.E.)
| | - Susanna Guatelli
- Centre For Medical Radiation Physics, University of Wollongong, Wollongong 2522, Australia;
| | - Sebastien Incerti
- Centre d’Études Nucléaires de Bordeaux Gradignan, CNRS/IN2P3, UMR5797, Université de Bordeaux, F-33170 Gradignan, France;
| | - Taku Inaniwa
- Department of Accelerator and Medical Physics, Institute for Quantum Medical Science, QST, Chiba 263-8555, Japan; (Y.A.); (M.M.); (S.S.); (T.I.)
| |
Collapse
|
8
|
Klebowski B, Depciuch J, Stec M, Krzempek D, Komenda W, Baran J, Parlinska-Wojtan M. Fancy-Shaped Gold-Platinum Nanocauliflowers for Improved Proton Irradiation Effect on Colon Cancer Cells. Int J Mol Sci 2020; 21:ijms21249610. [PMID: 33348549 PMCID: PMC7766784 DOI: 10.3390/ijms21249610] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 12/14/2020] [Accepted: 12/15/2020] [Indexed: 12/19/2022] Open
Abstract
Enhancing the effectiveness of colorectal cancer treatment is highly desirable. Radiation-based anticancer therapy—such as proton therapy (PT)—can be used to shrink tumors before subsequent surgical intervention; therefore, improving the effectiveness of this treatment is crucial. The addition of noble metal nanoparticles (NPs), acting as radiosensitizers, increases the PT therapeutic effect. Thus, in this paper, the effect of novel, gold–platinum nanocauliflowers (AuPt NCs) on PT efficiency is determined. For this purpose, crystalline, 66-nm fancy shaped, bimetallic AuPt NCs were synthesized using green chemistry method. Then, physicochemical characterization of the obtained AuPt NCs by transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive X-ray spectroscopy (EDS), and UV-Vis spectra measurements was carried out. Fully characterized AuPt NCs were placed into a cell culture of colon cancer cell lines (HCT116, SW480, and SW620) and a normal colon cell line (FHC) and subsequently subjected to proton irradiation with a total dose of 15 Gy. The 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) test, performed after 18-h incubation of the irradiated cell culture with AuPt NCs, showed a significant reduction in cancer cell viability compared to normal cells. Thus, the radio-enhancing features of AuPt NCs indicate their potential application for the improvement in effectiveness of anticancer proton therapy.
Collapse
Affiliation(s)
- Bartosz Klebowski
- Institute of Nuclear Physics Polish Academy of Sciences, 31-342 Krakow, Poland; (B.K.); (J.D.); (D.K.); (W.K.)
| | - Joanna Depciuch
- Institute of Nuclear Physics Polish Academy of Sciences, 31-342 Krakow, Poland; (B.K.); (J.D.); (D.K.); (W.K.)
| | - Malgorzata Stec
- Department of Clinical Immunology, Jagiellonian University Medical College, 30-663 Krakow, Poland;
| | - Dawid Krzempek
- Institute of Nuclear Physics Polish Academy of Sciences, 31-342 Krakow, Poland; (B.K.); (J.D.); (D.K.); (W.K.)
| | - Wiktor Komenda
- Institute of Nuclear Physics Polish Academy of Sciences, 31-342 Krakow, Poland; (B.K.); (J.D.); (D.K.); (W.K.)
| | - Jarek Baran
- Department of Clinical Immunology, Jagiellonian University Medical College, 30-663 Krakow, Poland;
- Correspondence: (J.B.); (M.P.-W.)
| | - Magdalena Parlinska-Wojtan
- Institute of Nuclear Physics Polish Academy of Sciences, 31-342 Krakow, Poland; (B.K.); (J.D.); (D.K.); (W.K.)
- Correspondence: (J.B.); (M.P.-W.)
| |
Collapse
|
9
|
Rahman M, Brůža P, Langen KM, Gladstone DJ, Cao X, Pogue BW, Zhang R. Characterization of a new scintillation imaging system for proton pencil beam dose rate measurements. Phys Med Biol 2020; 65:165014. [PMID: 32428888 DOI: 10.1088/1361-6560/ab9452] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The goal of this work was to create a technique that could measure all possible spatial and temporal delivery rates used in pencil-beam scanning (PBS) proton therapy. The proposed system used a fast scintillation screen for full-field imaging to resolve temporal and spatial patterns as it was delivered. A fast intensified CMOS camera used continuous mode with 10 ms temporal frame rate and 1 × 1 mm2 spatial resolution, imaging a scintillation screen during clinical proton PBS delivery. PBS plans with varying dose, dose rate, energy, field size, and spot-spacing were generated, delivered and imaged. The captured images were post processed to provide dose and dose rate values after background subtraction, perspective transformation, uniformity correction for the camera and the scintillation screen, and calibration into dose. The linearity in scintillation response with respect to varying dose rate, dose, and field size was within 2%. The quenching corrected response with varying energy was also within 2%. Large spatio-temporal variations in dose rate were observed, even for plans delivered with similar dose distributions. Dose and dose rate histograms and maximum dose rate maps were generated for quantitative evaluations. With the fastest PBS delivery on a clinical system, dose rates up to 26.0 Gy s-1 were resolved. The scintillation imaging technique was able to quantify proton PBS dose rate profiles with spot weight as low as 2 MU, with spot-spacing of 2.5 mm, having a 1 × 1 mm2 spatial resolution. These dose rate temporal profiles, spatial maps, and cumulative dose rate histograms provide useful metrics for the potential evaluation and optimization of dose rate in treatment plans.
Collapse
Affiliation(s)
- Mahbubur Rahman
- Thayer School of Engineering, Dartmouth College, Hanover, NH, United States of America
| | | | | | | | | | | | | |
Collapse
|
10
|
Preparation of a radiobiology beam line at the 18 MeV proton cyclotron facility at CNA. Phys Med 2020; 74:19-29. [DOI: 10.1016/j.ejmp.2020.04.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 04/22/2020] [Indexed: 11/23/2022] Open
|
11
|
Mazal A, Prezado Y, Ares C, de Marzi L, Patriarca A, Miralbell R, Favaudon V. FLASH and minibeams in radiation therapy: the effect of microstructures on time and space and their potential application to protontherapy. Br J Radiol 2020; 93:20190807. [PMID: 32003574 PMCID: PMC7066940 DOI: 10.1259/bjr.20190807] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
After years of lethargy, studies on two non-conventional microstructures in time and space of the beams used in radiation therapy are enjoying a huge revival. The first effect called “FLASH” is based on very high dose-rate irradiation (pulse amplitude ≥106 Gy/s), short beam-on times (≤100 ms) and large single doses (≥10 Gy) as experimental parameters established so far to give biological and potential clinical effects. The second effect relies on the use of arrays of minibeams (e.g., 0.5–1 mm, spaced 1–3.5 mm). Both approaches have been shown to protect healthy tissues as an endpoint that must be clearly specified and could be combined with each other (e.g., minibeams under FLASH conditions). FLASH depends on the presence of oxygen and could proceed from the chemistry of peroxyradicals and a reduced incidence on DNA and membrane damage. Minibeams action could be based on abscopal effects, cell signalling and/or migration of cells between “valleys and hills” present in the non-uniform irradiation field as well as faster repair of vascular damage. Both effects are expected to maintain intact the tumour control probability and might even preserve antitumoural immunological reactions. FLASH in vivo experiments involving Zebrafish, mice, pig and cats have been done with electron beams, while minibeams are an intermediate approach between X-GRID and synchrotron X-ray microbeams radiation. Both have an excellent rationale to converge and be applied with proton beams, combining focusing properties and high dose rates in the beam path of pencil beams, and the inherent advantage of a controlled limited range. A first treatment with electron FLASH (cutaneous lymphoma) has recently been achieved, but clinical trials have neither been presented for FLASH with protons, nor under the minibeam conditions. Better understanding of physical, chemical and biological mechanisms of both effects is essential to optimize the technical developments and devise clinical trials.
Collapse
Affiliation(s)
| | - Yolanda Prezado
- IMNC, University Paris-Sud and Paris-Saclay, CNRS/IN2P3, Orsay, France
| | - Carme Ares
- Centro de Protonterapia Quironsalud, Madrid, Spain
| | - Ludovic de Marzi
- Institut Curie, Institut Curie, PSL Research University, Centre de protonthérapie d'Orsay, Campus universitaire, bâtiment 101, Orsay 91898, France.,Institut Curie, Inserm U 1021-CNRS UMR 3347, Paris-Saclay and PSL Research Universities, Orsay, France
| | - Annalisa Patriarca
- Institut Curie, Institut Curie, PSL Research University, Centre de protonthérapie d'Orsay, Campus universitaire, bâtiment 101, Orsay 91898, France
| | | | - Vincent Favaudon
- Institut Curie, Inserm U 1021-CNRS UMR 3347, Paris-Saclay and PSL Research Universities, Orsay, France
| |
Collapse
|
12
|
Ultra high dose rate (35 Gy/sec) radiation does not spare the normal tissue in cardiac and splenic models of lymphopenia and gastrointestinal syndrome. Sci Rep 2019; 9:17180. [PMID: 31748640 PMCID: PMC6868225 DOI: 10.1038/s41598-019-53562-y] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 11/04/2019] [Indexed: 12/13/2022] Open
Abstract
Recent reports have shown that very high dose rate radiation (35–100 Gy/second) referred to as FLASH tends to spare the normal tissues while retaining the therapeutic effect on tumor. We undertook a series of experiments to assess if ultra-high dose rate of 35 Gy/second can spare the immune system in models of radiation induced lymphopenia. We compared the tumoricidal potency of ultra-high dose rate and conventional dose rate radiation using a classical clonogenic assay in murine pancreatic cancer cell lines. We also assessed the lymphocyte sparing potential in cardiac and splenic irradiation models of lymphopenia and assessed the severity of radiation-induced gastrointestinal toxicity triggered by the two dose rate regimes in vivo. Ultra-high dose rate irradiation more potently induces clonogenic cell death than conventional dose rate irradiation with a dose enhancement factor at 10% survival (DEF10) of 1.310 and 1.365 for KPC and Panc02 cell lines, respectively. Ultra-high dose rate was equally potent in depleting CD3, CD4, CD8, and CD19 lymphocyte populations in both cardiac and splenic irradiation models of lymphopenia. Radiation-induced gastrointestinal toxicity was more pronounced and mouse survival (7 days vs. 15 days, p = 0.0001) was inferior in the ultra-high dose rate arm compared to conventional dose rate arm. These results suggest that, contrary to published data in other models of radiation-induced acute and chronic toxicity, dose rates of 35 Gy/s do not protect mice from the detrimental side effects of irradiation in our models of cardiac and splenic radiation-induced lymphopenia or gastrointestinal mucosal injury.
Collapse
|
13
|
Colangelo NW, Azzam EI. The Importance and Clinical Implications of FLASH Ultra-High Dose-Rate Studies for Proton and Heavy Ion Radiotherapy. Radiat Res 2019; 193:1-4. [PMID: 31657670 DOI: 10.1667/rr15537.1] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The goal of radiation therapy is to provide the highest probability of tumor control while minimizing normal tissue toxicity. Recently, it has been discovered that ultra-high dose rates of ionizing radiation may preferentially spare normal tissue over tumor tissue. This effect, referred to as FLASH radiotherapy, has been observed in various animal models as well as, more recently, in a human patient. This effect may be related to the cell sparing found in vitro at ultra-high dose rates of photons and electrons dating back to the 1960s. Conditions representative of physiologic oxygen were found to be essential for this process to occur. However, there is no conclusive data on whether this effect occurs with protons, as all results to date have been in cells irradiated at ambient oxygen conditions. There have been no ultra-high dose-rate experiments with heavy ions, which would be relevant to the implementation of FLASH to carbon-ion therapy. These basic science results are critical in guiding this rapidly advancing field, since clinical particle therapy machines capable of FLASH dose rates have already been promoted for protons. To help ensure FLASH radiotherapy is reliable and maximally effective, the radiobiology must keep ahead of the clinical implementation to help guide it. In this context, in vitro and in vivo proton and heavy ion experiments involving FLASH dose rates need to be performed to evaluate not only short-term consequences, but also sequelae related to long-term health risks. Critical to these future studies is consideration of relevant oxygen tensions at the time of irradiation, as well as appropriate in silico modeling to assist in understanding the initial physicochemical events.
Collapse
Affiliation(s)
- Nicholas W Colangelo
- Rutgers Biomedical and Health Sciences, New Jersey Medical School, Department of Radiology, Newark, New Jersey
| | - Edouard I Azzam
- Rutgers Biomedical and Health Sciences, New Jersey Medical School, Department of Radiology, Newark, New Jersey
| |
Collapse
|
14
|
A Plasma Focus device as ultra-high dose rate pulsed radiation source. Part I: Primary electron beam characterization. Radiat Phys Chem Oxf Engl 1993 2019. [DOI: 10.1016/j.radphyschem.2019.02.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
15
|
Qi Tan H, Yang Calvin Koh W, Kuan Rui Tan L, Hao Phua J, Wei Ang K, Yong Park S, Siang Lew W, Cheow Lei Lee J. Dependence of LET on material and its impact on current RBE model. ACTA ACUST UNITED AC 2019; 64:135022. [DOI: 10.1088/1361-6560/ab1c90] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
16
|
Buonanno M, Grilj V, Brenner DJ. Biological effects in normal cells exposed to FLASH dose rate protons. Radiother Oncol 2019; 139:51-55. [PMID: 30850209 DOI: 10.1016/j.radonc.2019.02.009] [Citation(s) in RCA: 156] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 02/04/2019] [Accepted: 02/11/2019] [Indexed: 12/29/2022]
Abstract
BACKGROUND Radiotherapy outcomes are limited by toxicity in the healthy tissues surrounding the irradiated tumor. Recent pre-clinical studies have shown that irradiations with electrons or photons delivered at so called FLASH dose rates (i.e. >40 Gy/s) dramatically reduce adverse side effects in the normal tissues while being equally efficient for tumor control as irradiations at conventional dose rates (3-5 cGy/s). In the case of protons however, FLASH effects have not been investigated partially because of the limited availability of facilities that can achieve such high dose rates. METHODS Using a novel irradiation platform, we measured acute and long-term biological effects in normal human lung fibroblasts (IMR90) exposed to therapeutically relevant doses of 4.5 MeV protons (LET = 10 keV/µm) delivered at dose rates spanning four orders of magnitude. Endpoints included clonogenic cell survival, γH2AX foci formation, induction of premature senescence (β-gal), and the expression of the pro-inflammatory marker TGFβ. RESULTS Proton dose rate had no influence on the cell survival, but for the highest dose rate used (i.e. 1000 Gy/s) foci formation saturated beyond 10 Gy. In the progeny of irradiated cells, an increase in dose (20 Gy vs. 10 Gy) and dose rate (1000 Gy/s vs. 0.05 Gy/s) positively affected the number of senescence cells and the expression of TGFβ1. CONCLUSIONS In normal lung fibroblasts proton dose rate had little impact on acute effects, but significantly influenced the expression of long-term biological responses in vitro. Compared to conventional dose rates, protons delivered at FLASH dose rates mitigated such delayed detrimental effects.
Collapse
Affiliation(s)
- Manuela Buonanno
- Radiological Research Accelerator Facility (RARAF), New York, United States.
| | - Veljko Grilj
- Radiological Research Accelerator Facility (RARAF), New York, United States.
| | - David J Brenner
- Radiological Research Accelerator Facility (RARAF), New York, United States.
| |
Collapse
|
17
|
Fathi K, Galer S, Kirkby K, Palmans H, Nisbet A. Coupling Monte Carlo simulations with thermal analysis for correcting microdosimetric spectra from a novel micro-calorimeter. Radiat Phys Chem Oxf Engl 1993 2017. [DOI: 10.1016/j.radphyschem.2017.02.055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
18
|
Relative biological effectiveness in a proton spread-out Bragg peak formed by pencil beam scanning mode. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2017; 40:359-368. [PMID: 28321635 DOI: 10.1007/s13246-017-0540-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 03/09/2017] [Indexed: 10/19/2022]
Abstract
In recent years, there is an increased interest in using scanning modes in proton therapy, due to the more conformal dose distributions, thanks to the spot-weighted dose delivery. The dose rate in each spot is however much higher than the dose rate when using passive irradiation modes, which could affect the cell response. The purpose of this work was to investigate how the relative biological effectiveness changes along the spread-out Bragg peak created by protons delivered by the pencil beam scanning mode. Cell survival and micronuclei formation were investigated in four positions along the spread-out Bragg peak for various doses. Monte Carlo simulations were used to estimate the dose-averaged linear energy transfer values in the irradiation positions. The cell survival was found to decrease the deeper the sample was placed in the spread-out Bragg peak, which corresponds to the higher linear energy transfer values found using Monte Carlo simulations. The micronuclei frequencies indicate more complex cell injuries at that distal position compared to the proximal part of the spread-out Bragg peak. The relative biological effectiveness determined in this study varies significantly and systematically from 1.1, which is recommended value by the International Commission on Radiation Units, in all the studied positions. In the distal position of spread-out Bragg peak the relative biological effectiveness values were found to be 2.05 ± 0.44, 1.85 ± 0.42, 1.53 ± 0.38 for survival levels 90, 50 and 10%, respectively.
Collapse
|
19
|
Schüler E, Trovati S, King G, Lartey F, Rafat M, Villegas M, Praxel AJ, Loo BW, Maxim PG. Experimental Platform for Ultra-high Dose Rate FLASH Irradiation of Small Animals Using a Clinical Linear Accelerator. Int J Radiat Oncol Biol Phys 2017; 97:195-203. [DOI: 10.1016/j.ijrobp.2016.09.018] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 08/15/2016] [Accepted: 09/14/2016] [Indexed: 11/24/2022]
|
20
|
Favaudon V, Fouillade C, Vozenin MC. Radiothérapie « flash » à très haut débit de dose : un moyen d’augmenter l’indice thérapeutique par minimisation des dommages aux tissus sains ? Cancer Radiother 2015; 19:526-31. [DOI: 10.1016/j.canrad.2015.04.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Accepted: 04/29/2015] [Indexed: 01/27/2023]
|
21
|
Fuchs H, Alber M, Schreiner T, Georg D. Implementation of spot scanning dose optimization and dose calculation for helium ions in Hyperion. Med Phys 2015; 42:5157-66. [DOI: 10.1118/1.4927789] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
|
22
|
Gotz M, Karsch L, Pawelke J. Comparative investigation of three dose rate meters for their viability in pulsed radiation fields. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2015; 35:415-428. [PMID: 25978117 DOI: 10.1088/0952-4746/35/2/415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Pulsed radiation fields, characterized by microsecond pulse duration and correspondingly high pulse dose rates, are increasingly used in therapeutic, diagnostic and research applications. Yet, dose rate meters which are used to monitor radiation protection areas or to inspect radiation shielding are mostly designed, characterized and tested for continuous fields and show severe deficiencies in highly pulsed fields. Despite general awareness of the problem, knowledge of the specific limitations of individual instruments is very limited, complicating reliable measurements. We present here the results of testing three commercial dose rate meters, the RamION ionization chamber, the LB 1236-H proportional counter and the 6150AD-b scintillation counter, for their response in pulsed radiation fields of varied pulse dose and duration. Of these three the RamION proved reliable, operating in a pulsed radiation field within its specifications, while the other two instruments were only able to measure very limited pulse doses and pulse dose rates reliably.
Collapse
Affiliation(s)
- M Gotz
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, PF 41, 01307 Dresden, Germany
| | | | | |
Collapse
|
23
|
Favaudon V, Caplier L, Monceau V, Pouzoulet F, Sayarath M, Fouillade C, Poupon MF, Brito I, Hupé P, Bourhis J, Hall J, Fontaine JJ, Vozenin MC. Ultrahigh dose-rate FLASH irradiation increases the differential response between normal and tumor tissue in mice. Sci Transl Med 2015; 6:245ra93. [PMID: 25031268 DOI: 10.1126/scitranslmed.3008973] [Citation(s) in RCA: 652] [Impact Index Per Article: 72.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In vitro studies suggested that sub-millisecond pulses of radiation elicit less genomic instability than continuous, protracted irradiation at the same total dose. To determine the potential of ultrahigh dose-rate irradiation in radiotherapy, we investigated lung fibrogenesis in C57BL/6J mice exposed either to short pulses (≤ 500 ms) of radiation delivered at ultrahigh dose rate (≥ 40 Gy/s, FLASH) or to conventional dose-rate irradiation (≤ 0.03 Gy/s, CONV) in single doses. The growth of human HBCx-12A and HEp-2 tumor xenografts in nude mice and syngeneic TC-1 Luc(+) orthotopic lung tumors in C57BL/6J mice was monitored under similar radiation conditions. CONV (15 Gy) triggered lung fibrosis associated with activation of the TGF-β (transforming growth factor-β) cascade, whereas no complications developed after doses of FLASH below 20 Gy for more than 36 weeks after irradiation. FLASH irradiation also spared normal smooth muscle and epithelial cells from acute radiation-induced apoptosis, which could be reinduced by administration of systemic TNF-α (tumor necrosis factor-α) before irradiation. In contrast, FLASH was as efficient as CONV in the repression of tumor growth. Together, these results suggest that FLASH radiotherapy might allow complete eradication of lung tumors and reduce the occurrence and severity of early and late complications affecting normal tissue.
Collapse
Affiliation(s)
- Vincent Favaudon
- Institut Curie, Centre de Recherche, 91405 Orsay, France. INSERM U612, 91405 Orsay, France.
| | - Laura Caplier
- Pathology Laboratory, Ecole Nationale Vétérinaire d'Alfort, Université Paris-Est, 94704 Maisons Alfort, France
| | - Virginie Monceau
- Université Paris-XI, 91405 Orsay, France. INSERM U1030, Institut Gustave-Roussy, 94805 Villejuif, France
| | - Frédéric Pouzoulet
- Institut Curie, Centre de Recherche, 91405 Orsay, France. INSERM U612, 91405 Orsay, France
| | - Mano Sayarath
- Institut Curie, Centre de Recherche, 91405 Orsay, France. INSERM U612, 91405 Orsay, France
| | - Charles Fouillade
- Institut Curie, Centre de Recherche, 91405 Orsay, France. INSERM U612, 91405 Orsay, France
| | - Marie-France Poupon
- Institut Curie, Centre de Recherche, 91405 Orsay, France. INSERM U612, 91405 Orsay, France
| | - Isabel Brito
- Institut Curie, Centre de Recherche, 75248 Paris 05, France. INSERM U900, 75248 Paris 05, France
| | - Philippe Hupé
- Institut Curie, Centre de Recherche, 75248 Paris 05, France. INSERM U900, 75248 Paris 05, France. Mines ParisTech, 77305 Fontainebleau, France. CNRS, UMR144, 75248 Paris 05, France
| | - Jean Bourhis
- Université Paris-XI, 91405 Orsay, France. INSERM U1030, Institut Gustave-Roussy, 94805 Villejuif, France. Radio-Oncologie/Radiothérapie, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland
| | - Janet Hall
- Institut Curie, Centre de Recherche, 91405 Orsay, France. INSERM U612, 91405 Orsay, France
| | - Jean-Jacques Fontaine
- Pathology Laboratory, Ecole Nationale Vétérinaire d'Alfort, Université Paris-Est, 94704 Maisons Alfort, France
| | - Marie-Catherine Vozenin
- Université Paris-XI, 91405 Orsay, France. INSERM U1030, Institut Gustave-Roussy, 94805 Villejuif, France. Radio-Oncologie/Radiothérapie, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland. INSERM U967, Commissariat à l'Énergie Atomique (CEA), Division des Sciences du Vivant (DSV), Institut de Radiobiologie Cellulaire et Moléculaire (IRCM), 92265 Fontenay aux Roses, France
| |
Collapse
|
24
|
Cortés-Giraldo MA, Carabe A. A critical study of different Monte Carlo scoring methods of dose average linear-energy-transfer maps calculated in voxelized geometries irradiated with clinical proton beams. Phys Med Biol 2015; 60:2645-69. [PMID: 25768028 DOI: 10.1088/0031-9155/60/7/2645] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We compare unrestricted dose average linear energy transfer (LET) maps calculated with three different Monte Carlo scoring methods in voxelized geometries irradiated with proton therapy beams with three different Monte Carlo scoring methods. Simulations were done with the Geant4 (Geometry ANd Tracking) toolkit. The first method corresponds to a step-by-step computation of LET which has been reported previously in the literature. We found that this scoring strategy is influenced by spurious high LET components, which relative contribution in the dose average LET calculations significantly increases as the voxel size becomes smaller. Dose average LET values calculated for primary protons in water with voxel size of 0.2 mm were a factor ~1.8 higher than those obtained with a size of 2.0 mm at the plateau region for a 160 MeV beam. Such high LET components are a consequence of proton steps in which the condensed-history algorithm determines an energy transfer to an electron of the material close to the maximum value, while the step length remains limited due to voxel boundary crossing. Two alternative methods were derived to overcome this problem. The second scores LET along the entire path described by each proton within the voxel. The third followed the same approach of the first method, but the LET was evaluated at each step from stopping power tables according to the proton kinetic energy value. We carried out microdosimetry calculations with the aim of deriving reference dose average LET values from microdosimetric quantities. Significant differences between the methods were reported either with pristine or spread-out Bragg peaks (SOBPs). The first method reported values systematically higher than the other two at depths proximal to SOBP by about 15% for a 5.9 cm wide SOBP and about 30% for a 11.0 cm one. At distal SOBP, the second method gave values about 15% lower than the others. Overall, we found that the third method gave the most consistent performance since it returned stable dose average LET values against simulation parameter changes and gave the best agreement with dose average LET estimations from microdosimetry calculations.
Collapse
Affiliation(s)
- M A Cortés-Giraldo
- Department of Atomic, Molecular and Nuclear Physics, Universidad de Sevilla, Seville, Spain
| | | |
Collapse
|
25
|
Paganetti H. Relative biological effectiveness (RBE) values for proton beam therapy. Variations as a function of biological endpoint, dose, and linear energy transfer. Phys Med Biol 2014; 59:R419-72. [PMID: 25361443 DOI: 10.1088/0031-9155/59/22/r419] [Citation(s) in RCA: 616] [Impact Index Per Article: 61.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Proton therapy treatments are based on a proton RBE (relative biological effectiveness) relative to high-energy photons of 1.1. The use of this generic, spatially invariant RBE within tumors and normal tissues disregards the evidence that proton RBE varies with linear energy transfer (LET), physiological and biological factors, and clinical endpoint. Based on the available experimental data from published literature, this review analyzes relationships of RBE with dose, biological endpoint and physical properties of proton beams. The review distinguishes between endpoints relevant for tumor control probability and those potentially relevant for normal tissue complication. Numerous endpoints and experiments on sub-cellular damage and repair effects are discussed. Despite the large amount of data, considerable uncertainties in proton RBE values remain. As an average RBE for cell survival in the center of a typical spread-out Bragg peak (SOBP), the data support a value of ~1.15 at 2 Gy/fraction. The proton RBE increases with increasing LETd and thus with depth in an SOBP from ~1.1 in the entrance region, to ~1.15 in the center, ~1.35 at the distal edge and ~1.7 in the distal fall-off (when averaged over all cell lines, which may not be clinically representative). For small modulation widths the values could be increased. Furthermore, there is a trend of an increase in RBE as (α/β)x decreases. In most cases the RBE also increases with decreasing dose, specifically for systems with low (α/β)x. Data on RBE for endpoints other than clonogenic cell survival are too diverse to allow general statements other than that the RBE is, on average, in line with a value of ~1.1. This review can serve as a source for defining input parameters for applying or refining biophysical models and to identify endpoints where additional radiobiological data are needed in order to reduce the uncertainties to clinically acceptable levels.
Collapse
Affiliation(s)
- Harald Paganetti
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, 30 Fruit Street, Boston, MA 02114, USA
| |
Collapse
|
26
|
Matsumoto Y, Matsuura T, Wada M, Egashira Y, Nishio T, Furusawa Y. Enhanced radiobiological effects at the distal end of a clinical proton beam: in vitro study. JOURNAL OF RADIATION RESEARCH 2014; 55:816-22. [PMID: 24824674 PMCID: PMC4099988 DOI: 10.1093/jrr/rrt230] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Revised: 12/13/2013] [Accepted: 12/28/2013] [Indexed: 05/21/2023]
Abstract
In the clinic, the relative biological effectiveness (RBE) value of 1.1 has usually been used in relation to the whole depth of the spread-out Bragg-peak (SOBP) of proton beams. The aim of this study was to confirm the actual biological effect in the SOBP at the very distal end of clinical proton beams using an in vitro cell system. A human salivary gland tumor cell line, HSG, was irradiated with clinical proton beams (accelerated by 190 MeV/u) and examined at different depths in the distal part and the center of the SOBP. Surviving fractions were analyzed with the colony formation assay. Cell survival curves and the survival parameters were obtained by fitting with the linear-quadratic (LQ) model. The RBE at each depth of the proton SOBP compared with that for X-rays was calculated by the biological equivalent dose, and the biological dose distribution was calculated from the RBE and the absorbed dose at each position. Although the physical dose distribution was flat in the SOBP, the RBE values calculated by the equivalent dose were significantly higher (up to 1.56 times) at the distal end than at the center of the SOBP. Additionally, the range of the isoeffective dose was extended beyond the range of the SOBP (up to 4.1 mm). From a clinical point of view, this may cause unexpected side effects to normal tissues at the distal position of the beam. It is important that the beam design and treatment planning take into consideration the biological dose distribution.
Collapse
Affiliation(s)
- Yoshitaka Matsumoto
- Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Taeko Matsuura
- Advanced Medical Sciences, Graduate School of Medicine, Hokkaido University, 15-7 Kita, Kita-ku, Sapporo, Hokkaido, 060-8638, Japan Research Center for Innovative Oncology, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577, Japan
| | - Mami Wada
- Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Yusuke Egashira
- Research Center for Innovative Oncology, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577, Japan
| | - Teiji Nishio
- Research Center for Innovative Oncology, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577, Japan
| | - Yoshiya Furusawa
- Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| |
Collapse
|
27
|
Romano F, Cirrone GAP, Cuttone G, Rosa FD, Mazzaglia SE, Petrovic I, Fira AR, Varisano A. A Monte Carlo study for the calculation of the average linear energy transfer (LET) distributions for a clinical proton beam line and a radiobiological carbon ion beam line. Phys Med Biol 2014; 59:2863-82. [DOI: 10.1088/0031-9155/59/12/2863] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
28
|
McGowan SE, Burnet NG, Lomax AJ. Treatment planning optimisation in proton therapy. Br J Radiol 2013; 86:20120288. [PMID: 23255545 DOI: 10.1259/bjr.20120288] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The goal of radiotherapy is to achieve uniform target coverage while sparing normal tissue. In proton therapy, the same sources of geometric uncertainty are present as in conventional radiotherapy. However, an important and fundamental difference in proton therapy is that protons have a finite range, highly dependent on the electron density of the material they are traversing, resulting in a steep dose gradient at the distal edge of the Bragg peak. Therefore, an accurate knowledge of the sources and magnitudes of the uncertainties affecting the proton range is essential for producing plans which are robust to these uncertainties. This review describes the current knowledge of the geometric uncertainties and discusses their impact on proton dose plans. The need for patient-specific validation is essential and in cases of complex intensity-modulated proton therapy plans the use of a planning target volume (PTV) may fail to ensure coverage of the target. In cases where a PTV cannot be used, other methods of quantifying plan quality have been investigated. A promising option is to incorporate uncertainties directly into the optimisation algorithm. A further development is the inclusion of robustness into a multicriteria optimisation framework, allowing a multi-objective Pareto optimisation function to balance robustness and conformity. The question remains as to whether adaptive therapy can become an integral part of a proton therapy, to allow re-optimisation during the course of a patient's treatment. The challenge of ensuring that plans are robust to range uncertainties in proton therapy remains, although these methods can provide practical solutions.
Collapse
Affiliation(s)
- S E McGowan
- Department of Oncology, University of Cambridge, Cambridge, UK.
| | | | | |
Collapse
|
29
|
Echeverria AE, McCurdy M, Castillo R, Bernard V, Ramos NV, Buckley W, Castillo E, Liu P, Martinez J, Guerrero T. Proton therapy radiation pneumonitis local dose-response in esophagus cancer patients. Radiother Oncol 2012; 106:124-9. [PMID: 23127772 DOI: 10.1016/j.radonc.2012.09.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Revised: 08/03/2012] [Accepted: 09/06/2012] [Indexed: 12/25/2022]
Abstract
PURPOSE This study quantifies pulmonary radiation toxicity in patients who received proton therapy for esophagus cancer. MATERIALS/METHODS We retrospectively studied 100 esophagus cancer patients treated with proton therapy. The linearity of the enhanced FDG uptake vs. proton dose was evaluated using the Akaike Information Criterion (AIC). Pneumonitis symptoms (RP) were assessed using the Common Toxicity Criteria for Adverse Events version 4.0 (CTCAEv4). The interaction of the imaging response with dosimetric parameters and symptoms was evaluated. RESULTS The RP scores were: 0 grade 4/5, 7 grade 3, 20 grade 2, 37 grade 1, and 36 grade 0. Each dosimetric parameter was significantly higher for the symptomatic group. The AIC winning models were 30 linear, 52 linear quadratic, and 18 linear logarithmic. There was no significant difference in the linear coefficient between models. The slope of the FDG vs. proton dose response was 0.022 for the symptomatic and 0.012 for the asymptomatic (p=0.014). Combining dosimetric parameters with the slope did not improve the sensitivity or accuracy in identifying symptomatic cases. CONCLUSIONS The proton radiation dose response on FDG PET/CT imaging exhibited a predominantly linear dose response on modeling. Symptomatic patients had a higher dose response slope.
Collapse
|
30
|
Hong Z, Kase Y, Moritake T, Gerelchuluun A, Sun L, Suzuki K, Terunuma T, Yasuoka K, Kumada H, Anzai K, Sakurai H, Sakae T, Tsuboi K. Lineal energy-based evaluation of oxidative DNA damage induced by proton beams and X-rays. Int J Radiat Biol 2012; 89:36-43. [PMID: 22901337 DOI: 10.3109/09553002.2012.715791] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To determine the oxidative capabilities of proton beams compared to X-rays based on lineal energy (y). MATERIALS AND METHODS Microdosimetry was used to determine y-values of 155 MeV protons. Salmon testes deoxyribonucleic acid (ST-DNA) in solution and human tumor cells (MOLT-4) were irradiated with 200 kV X-rays (X) or 155 MeV protons at their plateau (P) and near their Bragg-peak (B). 8-Hydroxydeoxyguanosine (8-OHdG) production was determined by high performance liquid chromatography. Double-strand breaks (DSB) in ST-DNA were evaluated by agarose gel electrophoresis and DSB in cell nuclei were evaluated by immunocytochemical analysis of phosphorylated histone H2AX (γH2AX) foci. Edaravone was used as a radical scavenger. RESULTS 8-OHdG yields in ST-DNA were significantly higher with X than with P or B, and they were significantly higher with P than with B. DSB yields in ST-DNA were higher with P than with B or X, although not statistically significant, and were nearly equal with B and X. Although γH2AX foci formation in MOLT-4 cells after each irradiation type was nearly identical, the addition of edaravone significantly inhibited foci formation only with X. CONCLUSIONS Our results indicated that radical-induced indirect DNA damage was significantly lower with proton beams than with X-rays.
Collapse
Affiliation(s)
- Zhengshan Hong
- Proton Medical Research Center, Graduate School of Comprehensive Human Sciences, University of Tsukuba
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Yu Z, Vanstalle M, La Tessa C, Jiang GL, Durante M. Biophysical characterization of a relativistic proton beam for image-guided radiosurgery. JOURNAL OF RADIATION RESEARCH 2012; 53:620-627. [PMID: 22843629 PMCID: PMC3393345 DOI: 10.1093/jrr/rrs007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 02/27/2012] [Indexed: 06/01/2023]
Abstract
We measured the physical and radiobiological characteristics of 1 GeV protons for possible applications in stereotactic radiosurgery (image-guided plateau-proton radiosurgery). A proton beam was accelerated at 1 GeV at the Brookhaven National Laboratory (Upton, NY) and a target in polymethyl methacrylate (PMMA) was used. Clonogenic survival was measured after exposures to 1-10 Gy in three mammalian cell lines. Measurements and simulations demonstrate that the lateral scattering of the beam is very small. The lateral dose profile was measured with or without the 20-cm plastic target, showing no significant differences up to 2 cm from the axis A large number of secondary swift protons are produced in the target and this leads to an increase of approximately 40% in the measured dose on the beam axis at 20 cm depth. The relative biological effectiveness at 10% survival level ranged between 1.0 and 1.2 on the beam axis, and was slightly higher off-axis. The very low lateral scattering of relativistic protons and the possibility of using online proton radiography during the treatment make them attractive for image-guided plateau (non-Bragg peak) stereotactic radiosurgery.
Collapse
Affiliation(s)
- Zhan Yu
- Biophysics Department, GSI Helmholtz Center for Heavy Ions Research, Planckstraße 1, 64291 Darmstadt, Germany
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, 270 Dong An Road, 200032 Shanghai, China
| | - Marie Vanstalle
- Biophysics Department, GSI Helmholtz Center for Heavy Ions Research, Planckstraße 1, 64291 Darmstadt, Germany
| | - Chiara La Tessa
- Biophysics Department, GSI Helmholtz Center for Heavy Ions Research, Planckstraße 1, 64291 Darmstadt, Germany
| | - Guo-Liang Jiang
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, 270 Dong An Road, 200032 Shanghai, China
| | - Marco Durante
- Biophysics Department, GSI Helmholtz Center for Heavy Ions Research, Planckstraße 1, 64291 Darmstadt, Germany
- Institute of Condensed Matter Physics, Darmstadt University of Technology, Hochshulstraße 3, 64289 Darmstadt, Germany
| |
Collapse
|
32
|
Kantemiris I, Karaiskos P, Papagiannis P, Angelopoulos A. Dose and dose averaged LET comparison of ¹H, ⁴He, ⁶Li, ⁸Be, ¹⁰B, ¹²C, ¹⁴N, and ¹⁶O ion beams forming a spread-out Bragg peak. Med Phys 2012; 38:6585-91. [PMID: 22149840 DOI: 10.1118/1.3662911] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Modern clinical accelerators are capable of producing ion beams from protons up to neon. This work compares the depth dose distribution and corresponding dose averaged linear energy transfer (LET) distribution, which is related to the biological effectiveness, for different ion beams (¹H, ⁴He, ⁶Li, ⁸Be, ¹⁰B, ¹²C, ¹⁴N, and ¹⁶O) using multi-energetic spectra in order to configure spread-out Bragg peaks (SOBP). METHODS Monte Carlo simulations were performed in order to configure a 5 cm SOBP at 8 cm depth in water for all the different ion beams. Physical dose and dose averaged LET distributions as a function of depth were then calculated and compared. The superposition of dose distribution of all ions is also presented for a two opposing fields configuration. Additional simulations were performed for (12)C beams to investigate the dependence of dose and dose averaged LET distributions on target depth and size, as well as beam configuration. These included simulations for a 3 cm SOBP at 7, 10, and 13 cm depth in water, a 6 cm SOBP at 7 depth in water, and two opposing fields of 6 cm SOBP. RESULTS Alpha particles and protons present superior physical depth dose distributions relative to the rest of the beams studied. Dose averaged LET distributions results suggest higher biological effectiveness in the target volume for carbon, nitrogen and oxygen ions. This is coupled, however, with relatively high LET values-especially for the last two ion species-outside the SOBP where healthy tissue would be located. Dose averaged LET distributions for ⁸Be and ¹⁰B beams show that they could be attractive alternatives to ¹²C for the treatment of small, not deeply seated lesions. The potential therapeutic effect of different ion beams studied in this work depends on target volume and position, as well as the number of beams used. CONCLUSIONS The optimization of beam modality for specific tumor cites remains an open question that warrants further investigation and clinically relevant results.
Collapse
Affiliation(s)
- I Kantemiris
- Nuclear and Particle Physics Section, Physics Department, University of Athens, Panepistimioupolis, Ilissia, 157 71 Athens, Greece.
| | | | | | | |
Collapse
|
33
|
Tachibana H, Uchida Y, Shiizuka H. Technical note: determination of the optimized image processing and template matching techniques for a patient intrafraction motion monitoring system. Med Phys 2012; 39:755-64. [PMID: 22320785 DOI: 10.1118/1.3675404] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE In this work, the authors determine the optimal template matching method and selection of pixel data for use in a system for monitoring patient intrafraction motion. METHODS The motion monitoring system is based on optical tracking of a marker block placed on the patient. The temporal resolution of the system was evaluated with a respiratory motion phantom. The phantom moved the marker with a peak-to-peak amplitude of 0.6-4.0 cm and a period of 1, 3, and 6 s. Three template matching methods were applied: Sum of squared difference (SSD), sum of absolute difference (SAD), and normalized cross-correlation (NCC) using each of four pixel color data schemes (RGB and gray level modified by one of three image processing steps). An in-house algorithm called auto region-of-interest (AutoROI) automatically reset the marker detection region-of-interest to improve the calculation speed. RESULTS RGB and gray level temporal resolutions were 54.22 ± 10.81 (1 SD) s and 12.70 ± 3.87 (1 SD) s, respectively. The temporal resolution when using SSD and SAD was higher than when using NCC. Positional accuracy was within 1 mm. Both values were within the tolerance specified by AAPM Task Group 142. To avoid misidentification of the marker, a threshold-based self-validation within the marker recognition system was implemented and was found to improve the tracking of motion with a high amplitude and short period. CONCLUSIONS An intrafraction motion monitoring system using SSD or SAD and applied to gray pixel data can achieve high temporal resolution and positional accuracy.
Collapse
Affiliation(s)
- Hidenobu Tachibana
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305-5847, USA.
| | | | | |
Collapse
|
34
|
|