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Guan F, Peeler C, Bronk L, Geng C, Taleei R, Randeniya S, Ge S, Mirkovic D, Grosshans D, Mohan R, Titt U. Analysis of the track- and dose-averaged LET and LET spectra in proton therapy using the geant4 Monte Carlo code. Med Phys 2016; 42:6234-47. [PMID: 26520716 DOI: 10.1118/1.4932217] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The motivation of this study was to find and eliminate the cause of errors in dose-averaged linear energy transfer (LET) calculations from therapeutic protons in small targets, such as biological cell layers, calculated using the geant 4 Monte Carlo code. Furthermore, the purpose was also to provide a recommendation to select an appropriate LET quantity from geant 4 simulations to correlate with biological effectiveness of therapeutic protons. METHODS The authors developed a particle tracking step based strategy to calculate the average LET quantities (track-averaged LET, LETt and dose-averaged LET, LETd) using geant 4 for different tracking step size limits. A step size limit refers to the maximally allowable tracking step length. The authors investigated how the tracking step size limit influenced the calculated LETt and LETd of protons with six different step limits ranging from 1 to 500 μm in a water phantom irradiated by a 79.7-MeV clinical proton beam. In addition, the authors analyzed the detailed stochastic energy deposition information including fluence spectra and dose spectra of the energy-deposition-per-step of protons. As a reference, the authors also calculated the averaged LET and analyzed the LET spectra combining the Monte Carlo method and the deterministic method. Relative biological effectiveness (RBE) calculations were performed to illustrate the impact of different LET calculation methods on the RBE-weighted dose. RESULTS Simulation results showed that the step limit effect was small for LETt but significant for LETd. This resulted from differences in the energy-deposition-per-step between the fluence spectra and dose spectra at different depths in the phantom. Using the Monte Carlo particle tracking method in geant 4 can result in incorrect LETd calculation results in the dose plateau region for small step limits. The erroneous LETd results can be attributed to the algorithm to determine fluctuations in energy deposition along the tracking step in geant 4. The incorrect LETd values lead to substantial differences in the calculated RBE. CONCLUSIONS When the geant 4 particle tracking method is used to calculate the average LET values within targets with a small step limit, such as smaller than 500 μm, the authors recommend the use of LETt in the dose plateau region and LETd around the Bragg peak. For a large step limit, i.e., 500 μm, LETd is recommended along the whole Bragg curve. The transition point depends on beam parameters and can be found by determining the location where the gradient of the ratio of LETd and LETt becomes positive.
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Affiliation(s)
- Fada Guan
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030
| | - Christopher Peeler
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030
| | - Lawrence Bronk
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030
| | - Changran Geng
- Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China and Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Reza Taleei
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030
| | - Sharmalee Randeniya
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030
| | - Shuaiping Ge
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030
| | - Dragan Mirkovic
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030
| | - David Grosshans
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 and Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030
| | - Radhe Mohan
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030
| | - Uwe Titt
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030
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102
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Underwood T, Paganetti H. Variable Proton Relative Biological Effectiveness: How Do We Move Forward? Int J Radiat Oncol Biol Phys 2016; 95:56-58. [DOI: 10.1016/j.ijrobp.2015.10.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 10/01/2015] [Indexed: 12/26/2022]
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103
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In the Battle Between Protons and Photons for Hematologic Malignancies, the Patient Must Win. Int J Radiat Oncol Biol Phys 2016; 95:43-45. [DOI: 10.1016/j.ijrobp.2015.09.043] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 09/28/2015] [Indexed: 11/17/2022]
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104
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Underwood T, Giantsoudi D, Moteabbed M, Zietman A, Efstathiou J, Paganetti H, Lu HM. Can We Advance Proton Therapy for Prostate? Considering Alternative Beam Angles and Relative Biological Effectiveness Variations When Comparing Against Intensity Modulated Radiation Therapy. Int J Radiat Oncol Biol Phys 2016; 95:454-464. [DOI: 10.1016/j.ijrobp.2016.01.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 01/06/2016] [Accepted: 01/12/2016] [Indexed: 12/27/2022]
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105
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Marshall TI, Chaudhary P, Michaelidesová A, Vachelová J, Davídková M, Vondráček V, Schettino G, Prise KM. Investigating the Implications of a Variable RBE on Proton Dose Fractionation Across a Clinical Pencil Beam Scanned Spread-Out Bragg Peak. Int J Radiat Oncol Biol Phys 2016; 95:70-77. [PMID: 27084630 PMCID: PMC4838672 DOI: 10.1016/j.ijrobp.2016.02.029] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 01/27/2016] [Accepted: 02/08/2016] [Indexed: 01/19/2023]
Abstract
Purpose To investigate the clinical implications of a variable relative biological effectiveness (RBE) on proton dose fractionation. Using acute exposures, the current clinical adoption of a generic, constant cell killing RBE has been shown to underestimate the effect of the sharp increase in linear energy transfer (LET) in the distal regions of the spread-out Bragg peak (SOBP). However, experimental data for the impact of dose fractionation in such scenarios are still limited. Methods and Materials Human fibroblasts (AG01522) at 4 key depth positions on a clinical SOBP of maximum energy 219.65 MeV were subjected to various fractionation regimens with an interfraction period of 24 hours at Proton Therapy Center in Prague, Czech Republic. Cell killing RBE variations were measured using standard clonogenic assays and were further validated using Monte Carlo simulations and parameterized using a linear quadratic formalism. Results Significant variations in the cell killing RBE for fractionated exposures along the proton dose profile were observed. RBE increased sharply toward the distal position, corresponding to a reduction in cell sparing effectiveness of fractionated proton exposures at higher LET. The effect was more pronounced at smaller doses per fraction. Experimental survival fractions were adequately predicted using a linear quadratic formalism assuming full repair between fractions. Data were also used to validate a parameterized variable RBE model based on linear α parameter response with LET that showed considerable deviations from clinically predicted isoeffective fractionation regimens. Conclusions The RBE-weighted absorbed dose calculated using the clinically adopted generic RBE of 1.1 significantly underestimates the biological effective dose from variable RBE, particularly in fractionation regimens with low doses per fraction. Coupled with an increase in effective range in fractionated exposures, our study provides an RBE dataset that can be used by the modeling community for the optimization of fractionated proton therapy.
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Affiliation(s)
- Thomas I Marshall
- Centre for Cancer Research and Cell Biology, Queen's University, Belfast, UK
| | - Pankaj Chaudhary
- Centre for Cancer Research and Cell Biology, Queen's University, Belfast, UK
| | - Anna Michaelidesová
- Department of Radiation Dosimetry, Nuclear Physics Institute CAS, Prague, Czech Republic; Proton Therapy Center Czech, Prague, Czech Republic; Department of Dosimetry and Application of Ionizing Radiation, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Prague, Czech Republic
| | - Jana Vachelová
- Department of Radiation Dosimetry, Nuclear Physics Institute CAS, Prague, Czech Republic
| | - Marie Davídková
- Department of Radiation Dosimetry, Nuclear Physics Institute CAS, Prague, Czech Republic
| | | | | | - Kevin M Prise
- Centre for Cancer Research and Cell Biology, Queen's University, Belfast, UK
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106
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Held KD, Kawamura H, Kaminuma T, Paz AES, Yoshida Y, Liu Q, Willers H, Takahashi A. Effects of Charged Particles on Human Tumor Cells. Front Oncol 2016; 6:23. [PMID: 26904502 PMCID: PMC4751258 DOI: 10.3389/fonc.2016.00023] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 01/21/2016] [Indexed: 12/22/2022] Open
Abstract
The use of charged particle therapy in cancer treatment is growing rapidly, in large part because the exquisite dose localization of charged particles allows for higher radiation doses to be given to tumor tissue while normal tissues are exposed to lower doses and decreased volumes of normal tissues are irradiated. In addition, charged particles heavier than protons have substantial potential clinical advantages because of their additional biological effects, including greater cell killing effectiveness, decreased radiation resistance of hypoxic cells in tumors, and reduced cell cycle dependence of radiation response. These biological advantages depend on many factors, such as endpoint, cell or tissue type, dose, dose rate or fractionation, charged particle type and energy, and oxygen concentration. This review summarizes the unique biological advantages of charged particle therapy and highlights recent research and areas of particular research needs, such as quantification of relative biological effectiveness (RBE) for various tumor types and radiation qualities, role of genetic background of tumor cells in determining response to charged particles, sensitivity of cancer stem-like cells to charged particles, role of charged particles in tumors with hypoxic fractions, and importance of fractionation, including use of hypofractionation, with charged particles.
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Affiliation(s)
- Kathryn D Held
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School , Boston, MA , USA
| | - Hidemasa Kawamura
- Gunma University Heavy Ion Medical Center, Gunma, Japan; Department of Radiation Oncology, Gunma University Graduate School of Medicine, Gunma, Japan
| | - Takuya Kaminuma
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Gunma University Heavy Ion Medical Center, Gunma, Japan; Department of Radiation Oncology, Gunma University Graduate School of Medicine, Gunma, Japan
| | | | - Yukari Yoshida
- Gunma University Heavy Ion Medical Center , Gunma , Japan
| | - Qi Liu
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School , Boston, MA , USA
| | - Henning Willers
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School , Boston, MA , USA
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107
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Granville DA, Sahoo N, Sawakuchi GO. Simultaneous measurements of absorbed dose and linear energy transfer in therapeutic proton beams. Phys Med Biol 2016; 61:1765-79. [DOI: 10.1088/0031-9155/61/4/1765] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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108
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Georgantzoglou A, Merchant MJ, Jeynes JCG, Mayhead N, Punia N, Butler RE, Jena R. Applications of High-Throughput Clonogenic Survival Assays in High-LET Particle Microbeams. Front Oncol 2016; 5:305. [PMID: 26835414 PMCID: PMC4724960 DOI: 10.3389/fonc.2015.00305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 12/18/2015] [Indexed: 11/13/2022] Open
Abstract
Charged particle therapy is increasingly becoming a valuable tool in cancer treatment, mainly due to the favorable interaction of particle radiation with matter. Its application is still limited due, in part, to lack of data regarding the radiosensitivity of certain cell lines to this radiation type, especially to high-linear energy transfer (LET) particles. From the earliest days of radiation biology, the clonogenic survival assay has been used to provide radiation response data. This method produces reliable data but it is not optimized for high-throughput microbeam studies with high-LET radiation where high levels of cell killing lead to a very low probability of maintaining cells' clonogenic potential. A new method, therefore, is proposed in this paper, which could potentially allow these experiments to be conducted in a high-throughput fashion. Cells are seeded in special polypropylene dishes and bright-field illumination provides cell visualization. Digital images are obtained and cell detection is applied based on corner detection, generating individual cell targets as x-y points. These points in the dish are then irradiated individually by a micron field size high-LET microbeam. Post-irradiation, time-lapse imaging follows cells' response. All irradiated cells are tracked by linking trajectories in all time-frames, based on finding their nearest position. Cell divisions are detected based on cell appearance and individual cell temporary corner density. The number of divisions anticipated is low due to the high probability of cell killing from high-LET irradiation. Survival curves are produced based on cell's capacity to divide at least four to five times. The process is repeated for a range of doses of radiation. Validation shows the efficiency of the proposed cell detection and tracking method in finding cell divisions.
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Affiliation(s)
| | - Michael J. Merchant
- Manchester Academic Health Science Centre, Institute of Cancer Sciences, University of Manchester, The Christie NHS Foundations Trust, Manchester, UK
| | | | | | - Natasha Punia
- Department of Microbial and Cellular Sciences, University of Surrey, Guildford, UK
| | - Rachel E. Butler
- Department of Microbial and Cellular Sciences, University of Surrey, Guildford, UK
| | - Rajesh Jena
- Department of Oncology, Addenbrooke’s Hospital, University of Cambridge, Cambridge, UK
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109
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Taleei R, Guan F, Peeler C, Bronk L, Patel D, Mirkovic D, Grosshans DR, Mohan R, Titt U. Monte Carlo simulations of3He ion physical characteristics in a water phantom and evaluation of radiobiological effectiveness. Med Phys 2016; 43:761-76. [DOI: 10.1118/1.4939440] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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110
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McNamara AL, Schuemann J, Paganetti H. A phenomenological relative biological effectiveness (RBE) model for proton therapy based on all published in vitro cell survival data. Phys Med Biol 2015; 60:8399-416. [PMID: 26459756 DOI: 10.1088/0031-9155/60/21/8399] [Citation(s) in RCA: 209] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Proton therapy treatments are currently planned and delivered using the assumption that the proton relative biological effectiveness (RBE) relative to photons is 1.1. This assumption ignores strong experimental evidence that suggests the RBE varies along the treatment field, i.e. with linear energy transfer (LET) and with tissue type. A recent review study collected over 70 experimental reports on proton RBE, providing a comprehensive dataset for predicting RBE for cell survival. Using this dataset we developed a model to predict proton RBE based on dose, dose average LET (LETd) and the ratio of the linear-quadratic model parameters for the reference radiation (α/β)x, as the tissue specific parameter. The proposed RBE model is based on the linear quadratic model and was derived from a nonlinear regression fit to 287 experimental data points. The proposed model predicts that the RBE increases with increasing LETd and decreases with increasing (α/β)x. This agrees with previous theoretical predictions on the relationship between RBE, LETd and (α/β)x. The model additionally predicts a decrease in RBE with increasing dose and shows a relationship between both α and β with LETd. Our proposed phenomenological RBE model is derived using the most comprehensive collection of proton RBE experimental data to date. Previously published phenomenological models, based on a limited data set, may have to be revised.
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Affiliation(s)
- Aimee L McNamara
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, 30 Fruit Street, Boston, MA 02114, USA
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Widder J, van der Schaaf A, Lambin P, Marijnen CAM, Pignol JP, Rasch CR, Slotman BJ, Verheij M, Langendijk JA. The Quest for Evidence for Proton Therapy: Model-Based Approach and Precision Medicine. Int J Radiat Oncol Biol Phys 2015; 95:30-36. [PMID: 26684410 DOI: 10.1016/j.ijrobp.2015.10.004] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 10/01/2015] [Indexed: 02/07/2023]
Abstract
PURPOSE Reducing dose to normal tissues is the advantage of protons versus photons. We aimed to describe a method for translating this reduction into a clinically relevant benefit. METHODS AND MATERIALS Dutch scientific and health care governance bodies have recently issued landmark reports regarding generation of relevant evidence for new technologies in health care including proton therapy. An approach based on normal tissue complication probability (NTCP) models has been adopted to select patients who are most likely to experience fewer (serious) adverse events achievable by state-of-the-art proton treatment. RESULTS By analogy with biologically targeted therapies, the technology needs to be tested in enriched cohorts of patients exhibiting the decisive predictive marker: difference in normal tissue dosimetric signatures between proton and photon treatment plans. Expected clinical benefit is then estimated by virtue of multifactorial NTCP models. In this sense, high-tech radiation therapy falls under precision medicine. As a consequence, randomizing nonenriched populations between photons and protons is predictably inefficient and likely to produce confusing results. CONCLUSIONS Validating NTCP models in appropriately composed cohorts treated with protons should be the primary research agenda leading to urgently needed evidence for proton therapy.
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Affiliation(s)
- Joachim Widder
- Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
| | - Arjen van der Schaaf
- Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Philippe Lambin
- Department of Radiation Oncology, School for Oncology and Developmental Biology (GROW), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Corrie A M Marijnen
- Department of Radiation Oncology, Leiden University Medical Center, Leiden, The Netherlands
| | - Jean-Philippe Pignol
- Department of Radiation Oncology, Erasmus Medical Center Cancer Institute, Rotterdam, The Netherlands
| | - Coen R Rasch
- Department of Radiation Oncology, Academic Medical Center, Amsterdam, The Netherlands
| | - Ben J Slotman
- Department of Radiation Oncology, VU Medical Center, Amsterdam, The Netherlands
| | - Marcel Verheij
- Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Johannes A Langendijk
- Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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