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Monte-Carlo techniques for radiotherapy applications I: introduction and overview of the different Monte-Carlo codes. JOURNAL OF RADIOTHERAPY IN PRACTICE 2023. [DOI: 10.1017/s1460396923000079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Abstract
Introduction:
The dose calculation plays a crucial role in many aspects of contemporary clinical radiotherapy treatment planning process. It therefore goes without saying that the accuracy of the dose calculation is of very high importance. The gold standard for absorbed dose calculation is the Monte-Carlo algorithm.
Methods:
This first of two papers gives an overview of the main openly available and supported codes that have been widely used for radiotherapy simulations.
Results:
The paper aims to provide an overview of Monte-Carlo in the field of radiotherapy and point the reader in the right direction of work that could help them get started or develop their existing understanding and use of Monte-Carlo algorithms in their practice.
Conclusions:
It also serves as a useful companion to a curated collection of papers on Monte-Carlo that have been published in this journal.
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Townson R, Egglestone H, Zavgorodni S. A fast jaw-tracking model for VMAT and IMRT Monte Carlo simulations. J Appl Clin Med Phys 2018; 19:26-34. [PMID: 29745009 PMCID: PMC6036353 DOI: 10.1002/acm2.12343] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 01/25/2018] [Accepted: 02/13/2018] [Indexed: 12/17/2022] Open
Abstract
Modern radiotherapy techniques involve routine use of volumetric arc therapy (VMAT) and intensity modulated radiotherapy (IMRT) with jaw‐tracking – dynamic motion of the secondary collimators (jaws) in tandem with multi‐leaf collimators (MLCs). These modalities require accurate dose calculations for the purposes of treatment planning and dose verification. Monte Carlo (MC) methods for radiotherapy dose calculation are widely accepted as capable of achieving high accuracy. This paper presents an efficiency‐enhancement method for secondary collimator modeling, presented in the context of a tool for MC‐based dose second checks. The model constitutes an accuracy trade‐off in the source model for the sake of efficiency enhancement, but maintains the advantages of MC transport in patient heterogeneities. The secondary collimator model is called Flat‐Absorbing‐Jaw‐Tracking (FAJT). Transmission through and scatter from the secondary collimators is neglected, and jaws are modeled as perfectly absorbing planes. To couple the motion of secondary collimators with MLCs for jaw‐tracking, the FAJT model was built into the VCU‐MLC model. Gamma‐index analysis of the dose distributions from FAJT against the full BEAMnrc MC simulations showed over 99% pass rate for a range of open fields, two clinical IMRT, and one VMAT treatment plan, for 2%/2 mm criteria above 10%. Using FAJT, the simulation speed of the secondary collimators for open fields increased by a factor of 237, 1489, and 1395 for 4 × 4, 10 × 10, and 30 × 30 cm2, respectively. In general, clinically oriented simulation times are reduced from “hours” to “minutes” on identical hardware. Results for nine representative clinical cases (seven with jaw‐tracking) are presented. The average 2%/2 mm γ‐test success rate above the 80% isodose was 96.8% when tested against the EPIDose electronic portal image‐based dose reconstruction method and 97.3% against the Eclipse analytical anisotropic algorithm.
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Affiliation(s)
- Reid Townson
- Measurement Science and Standards, National Research Council Canada, Ottawa, ON, Canada
| | - Hilary Egglestone
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada.,Department of Medical Physics, BC Cancer Agency, Vancouver Island Centre, Victoria, BC, Canada
| | - Sergei Zavgorodni
- Department of Medical Physics, BC Cancer Agency, Vancouver Island Centre, Victoria, BC, Canada
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Sterpin E. Potential pitfalls of the PTV concept in dose-to-medium planning optimization. Phys Med 2016; 32:1103-10. [PMID: 27546868 DOI: 10.1016/j.ejmp.2016.08.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 08/09/2016] [Accepted: 08/11/2016] [Indexed: 12/25/2022] Open
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Yang YM, Geurts M, Smilowitz JB, Sterpin E, Bednarz BP. Monte Carlo simulations of patient dose perturbations in rotational-type radiotherapy due to a transverse magnetic field: a tomotherapy investigation. Med Phys 2015; 42:715-25. [PMID: 25652485 DOI: 10.1118/1.4905168] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Several groups are exploring the integration of magnetic resonance (MR) image guidance with radiotherapy to reduce tumor position uncertainty during photon radiotherapy. The therapeutic gain from reducing tumor position uncertainty using intrafraction MR imaging during radiotherapy could be partially offset if the negative effects of magnetic field-induced dose perturbations are not appreciated or accounted for. The authors hypothesize that a more rotationally symmetric modality such as helical tomotherapy will permit a systematic mediation of these dose perturbations. This investigation offers a unique look at the dose perturbations due to homogeneous transverse magnetic field during the delivery of Tomotherapy(®) Treatment System plans under varying degrees of rotational beamlet symmetry. METHODS The authors accurately reproduced treatment plan beamlet and patient configurations using the Monte Carlo code geant4. This code has a thoroughly benchmarked electromagnetic particle transport physics package well-suited for the radiotherapy energy regime. The three approved clinical treatment plans for this study were for a prostate, head and neck, and lung treatment. The dose heterogeneity index metric was used to quantify the effect of the dose perturbations to the target volumes. RESULTS The authors demonstrate the ability to reproduce the clinical dose-volume histograms (DVH) to within 4% dose agreement at each DVH point for the target volumes and most planning structures, and therefore, are able to confidently examine the effects of transverse magnetic fields on the plans. The authors investigated field strengths of 0.35, 0.7, 1, 1.5, and 3 T. Changes to the dose heterogeneity index of 0.1% were seen in the prostate and head and neck case, reflecting negligible dose perturbations to the target volumes, a change from 5.5% to 20.1% was observed with the lung case. CONCLUSIONS This study demonstrated that the effect of external magnetic fields can be mitigated by exploiting a more rotationally symmetric treatment modality.
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Affiliation(s)
- Y M Yang
- Department of Medical Physics, Wisconsin Institutes for Medical Research, University of Wisconsin, Madison, Wisconsin 53703
| | - M Geurts
- Department of Medical Physics, Wisconsin Institutes for Medical Research, University of Wisconsin, Madison, Wisconsin 53703
| | - J B Smilowitz
- Department of Medical Physics, Wisconsin Institutes for Medical Research, University of Wisconsin, Madison, Wisconsin 53703
| | - E Sterpin
- Molecular Imaging, Radiotherapy and Oncology, Université catholique de Louvain, Brussels, Belgium 1348
| | - B P Bednarz
- Department of Medical Physics, Wisconsin Institutes for Medical Research, University of Wisconsin, Madison, Wisconsin 53703
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Sterpin E. Monte Carlo evaluation of the dose calculation algorithm of TomoTherapy for clinical cases in dynamic jaws mode. Phys Med 2015; 31:273-80. [PMID: 25661978 DOI: 10.1016/j.ejmp.2015.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 01/14/2015] [Accepted: 01/19/2015] [Indexed: 10/24/2022] Open
Abstract
PURPOSE For the TomoTherapy(®) system, longitudinal conformation can be improved by selecting a smaller field width but at the expense of longer treatment time. Recently, the TomoEdge(®) feature has been released with the possibility to move dynamically the jaws at the edges of the target volume, improving longitudinal penumbra and enabling faster treatments. Such delivery scheme requires additional modeling of treatment delivery. Using a previously validated Monte Carlo model (TomoPen), we evaluated the accuracy of the implementation of TomoEdge in the new dose engine of TomoTherapy for 15 clinical cases. METHODS TomoPen is based on PENELOPE. Particle tracking in the treatment head is performed almost instantaneously by 1) reading a particle from a phase-space file corresponding to the largest field and 2) correcting the weight of the particle depending on the actual jaw and MLC configurations using Monte Carlo pre-generated data. 15 clinical plans (5 head-and-neck, 5 lung and 5 prostate tumors) planned with TomoEdge and with the last release of the treatment planning system (VoLO(®)) were re-computed with TomoPen. The resulting dose-volume histograms were compared. RESULTS Good agreement was achieved overall, with deviations for the target volumes typically within 2% (D95), excepted for small lung tumors (17 cm(3)) where a maximum deviation of 4.4% was observed for D95. The results were consistent with previously reported values for static field widths. CONCLUSIONS For the clinical cases considered in the present study, the introduction of TomoEdge did not impact significantly the accuracy of the computed dose distributions.
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Affiliation(s)
- E Sterpin
- Center of Molecular Imaging, Radiotherapy and Oncology, Institut de recherche expérimentale et clinique, Université catholique de Louvain, Avenue Hippocrate 54, 1200 Brussels, Belgium.
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Pisaturo O, Miéville F, Tercier PA, Allal AS. An efficient procedure for tomotherapy treatment plan verification using the on-board detector. Phys Med Biol 2015; 60:1625-39. [DOI: 10.1088/0031-9155/60/4/1625] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Sarrut D, Bardiès M, Boussion N, Freud N, Jan S, Létang JM, Loudos G, Maigne L, Marcatili S, Mauxion T, Papadimitroulas P, Perrot Y, Pietrzyk U, Robert C, Schaart DR, Visvikis D, Buvat I. A review of the use and potential of the GATE Monte Carlo simulation code for radiation therapy and dosimetry applications. Med Phys 2015; 41:064301. [PMID: 24877844 DOI: 10.1118/1.4871617] [Citation(s) in RCA: 238] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
In this paper, the authors' review the applicability of the open-source GATE Monte Carlo simulation platform based on the GEANT4 toolkit for radiation therapy and dosimetry applications. The many applications of GATE for state-of-the-art radiotherapy simulations are described including external beam radiotherapy, brachytherapy, intraoperative radiotherapy, hadrontherapy, molecular radiotherapy, and in vivo dose monitoring. Investigations that have been performed using GEANT4 only are also mentioned to illustrate the potential of GATE. The very practical feature of GATE making it easy to model both a treatment and an imaging acquisition within the same framework is emphasized. The computational times associated with several applications are provided to illustrate the practical feasibility of the simulations using current computing facilities.
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Affiliation(s)
- David Sarrut
- Université de Lyon, CREATIS; CNRS UMR5220; Inserm U1044; INSA-Lyon; Université Lyon 1; Centre Léon Bérard, France
| | - Manuel Bardiès
- Inserm, UMR1037 CRCT, F-31000 Toulouse, France and Université Toulouse III-Paul Sabatier, UMR1037 CRCT, F-31000 Toulouse, France
| | | | - Nicolas Freud
- Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, Centre Léon Bérard, 69008 Lyon, France
| | | | - Jean-Michel Létang
- Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, Centre Léon Bérard, 69008 Lyon, France
| | - George Loudos
- Department of Medical Instruments Technology, Technological Educational Institute of Athens, Athens 12210, Greece
| | - Lydia Maigne
- UMR 6533 CNRS/IN2P3, Université Blaise Pascal, 63171 Aubière, France
| | - Sara Marcatili
- Inserm, UMR1037 CRCT, F-31000 Toulouse, France and Université Toulouse III-Paul Sabatier, UMR1037 CRCT, F-31000 Toulouse, France
| | - Thibault Mauxion
- Inserm, UMR1037 CRCT, F-31000 Toulouse, France and Université Toulouse III-Paul Sabatier, UMR1037 CRCT, F-31000 Toulouse, France
| | - Panagiotis Papadimitroulas
- Department of Biomedical Engineering, Technological Educational Institute of Athens, 12210, Athens, Greece
| | - Yann Perrot
- UMR 6533 CNRS/IN2P3, Université Blaise Pascal, 63171 Aubière, France
| | - Uwe Pietrzyk
- Institut für Neurowissenschaften und Medizin, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany and Fachbereich für Mathematik und Naturwissenschaften, Bergische Universität Wuppertal, 42097 Wuppertal, Germany
| | - Charlotte Robert
- IMNC, UMR 8165 CNRS, Universités Paris 7 et Paris 11, Orsay 91406, France
| | - Dennis R Schaart
- Delft University of Technology, Faculty of Applied Sciences, Radiation Science and Technology Department, Delft Mekelweg 15, 2629 JB Delft, The Netherlands
| | | | - Irène Buvat
- IMNC, UMR 8165 CNRS, Universités Paris 7 et Paris 11, 91406 Orsay, France and CEA/DSV/I2BM/SHFJ, 91400 Orsay, France
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Han EY, Kim DW, Zhang X, Penagaricano J, Liang X, Hardee M, Morrill S, Ratanatharathorn V. Dosimetric effect on pediatric conformal treatment plans using dynamic jaw with Tomotherapy HDA. Med Dosim 2015; 40:244-7. [DOI: 10.1016/j.meddos.2015.01.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 01/22/2015] [Accepted: 01/28/2015] [Indexed: 10/23/2022]
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Rong Y, Chen Y, Shang L, Zuo L, Lu W, Chen Q. Helical tomotherapy with dynamic running-start-stop delivery compared to conventional tomotherapy delivery. Med Phys 2014; 41:051709. [PMID: 24784375 DOI: 10.1118/1.4870987] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Despite superior target dose uniformity, helical tomotherapy(®) (HT) may involve a trade-off between longitudinal dose conformity and beam-on time (BOT), due to the limitation of only three available jaw sizes with the conventional HT (1.0, 2.5, and 5.0 cm). The recently introduced dynamic running-start-stop (RSS) delivery allows smaller jaw opening at the superior and inferior ends of the target when a sharp penumbra is needed. This study compared the dosimetric performance of RSS delivery with the fixed jaw HT delivery. METHODS Twenty patient cases were selected and deidentified prior to treatment planning, including 16 common clinical cases (brain, head and neck (HN), lung, and prostate) and four special cases of whole brain with hippocampus avoidance (WBHA) that require a high degree of dose modulation. HT plans were generated for common clinical cases using the fixed 2.5 cm jaw width (HT2.5) and WBHA cases using 1.0 cm (HT1.0). The jaw widths for RSS were preset with a larger size (RSS5.0 vs HT2.5 and RSS2.5 vs HT1.0). Both delivery techniques were planned based on identical contours, prescriptions, and planning objectives. Dose indices for targets and critical organs were compared using dose-volume histograms, BOT, and monitor units. RESULTS The average BOT was reduced from 4.8 min with HT2.5 to 2.5 min with RSS5.0. Target dose homogeneity with RSS5.0 was shown comparable to HT2.5 for common clinical sites. Superior normal tissue sparing was observed in RSS5.0 for optic nerves and optic chiasm in brain and HN cases. RSS5.0 demonstrated improved dose sparing for cord and esophagus in lung cases, as well as penile bulb in prostate cases. The mean body dose was comparable for both techniques. For the WBHA cases, the target homogeneity was significantly degraded in RSS2.5 without distinct dose sparing for hippocampus, compared to HT1.0. CONCLUSIONS Compared to the fixed jaw HT delivery, RSS combined with a larger jaw width provides faster treatment delivery and improved cranial-caudal target dose conformity. The target coverage achieved by RSS with a large jaw width is comparable to the fixed jaw HT delivery for common cancer sites, but may deteriorate for cases where complex geometry is present in the middle part of the target.
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Affiliation(s)
- Yi Rong
- Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, Ohio 43210
| | - Yu Chen
- 21st Century Oncology, Madison, Wisconsin 53719
| | - Lu Shang
- Guangxi Polytechnic of Construction and Technology, Nanning, China
| | - Li Zuo
- Radiologic Sciences and Respiratory Therapy Division, School of Health and Rehabilitation Sciences, The Ohio State University College of Medicine, Columbus, Ohio 43210
| | - Weiguo Lu
- 21st Century Oncology, Madison, Wisconsin 53719
| | - Quan Chen
- Department of Radiation Oncology, University of Virginia, Charlottesville, Virginia 22904
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Sterpin E, Verboomen C, Vynckier S. Impact of the number of discrete angles used during dose computation for TomoTherapy treatments. Med Phys 2012; 39:6947-56. [PMID: 23127088 DOI: 10.1118/1.4762684] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To quantify systematically the effect on accuracy of discretizing gantry rotation during the dose calculation process of TomoTherapy treatments. METHODS Up to version 4.0.x included, TomoTherapy treatment planning system (TPS) approximates gantry rotation by computing dose from 51 discrete angles corresponding to the center of the projections used to control the binary multileaf collimator. Potential effects on dose computation accuracy for off-axis targets and low modulation factors have been shown previously for a few treatment configurations. In versions 4.1.x and later, TomoTherapy oversamples the projections to better account for gantry rotation, but only during full scatter optimization and final calculation (i.e., not during optimization in "beamlet" mode). The effect on accuracy of changing the number of angles was quantified with the following framework: (1) predict the impact of the discretization of gantry rotation for various modulation factors, target sizes, and off-axis positions using a simplified analytical algorithm; (2) perform regular quality assurance using measurements with EDR2 radiographic films; (3) isolating the effect of changing the number of discretized angles only (51, 153, and 459) using a previously validated Monte Carlo model (TomoPen). The diameters of the targets were 2, 3, and 5 cm; off-axis central positions of target volumes were 5, 10 and 15, and 17 cm (when accepted by the treatment unit); planned modulation factors were 1.3 and 2.0. RESULTS For extreme configurations (3 cm tumor, 1.3 modulation factor, 15 cm off-axis position), effects on dose distributions were significant with 89.3% and 95.4% of the points passing gamma tests with 2%∕2 mm and 3%∕3 mm criteria, respectively, for TPS software version 4.0.x (51 gantry angles). The passing rate was 100% for both gamma criteria for the 4.1.x version (153 gantry angles). Those differences could be attributed almost completely to gantry motion discretization using TomoPen. Using 51 gantry angles for dose computation, TomoPen reproduced within statistical uncertainties (<1% standard deviation) dose distributions computed with version 4.0.x. Using 153 and 459 gantry angles, TomoPen reproduced within statistical uncertainties measurements and dose distributions computed with version 4.1.x. CONCLUSIONS When low modulation factors and significant off-axis positions are used, accounting for gantry rotation during dose computation using at least 153 gantry angles is required to ensure optimal accuracy.
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Affiliation(s)
- E Sterpin
- Université catholique de Louvain, Brussels, Belgium
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