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Kalinowski J, Enger SA. RapidBrachyTG43: A Geant4-based TG-43 parameter and dose calculation module for brachytherapy dosimetry. Med Phys 2024; 51:3746-3757. [PMID: 38252746 DOI: 10.1002/mp.16948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/05/2023] [Accepted: 12/19/2023] [Indexed: 01/24/2024] Open
Abstract
BACKGROUND The AAPM TG-43U1 formalism remains the clinical standard for dosimetry of low- and high-energy γ $\gamma$ -emitting brachytherapy sources. TG-43U1 and related reports provide consensus datasets of TG-43 parameters derived from various published measured data and Monte Carlo simulations. These data are used to perform standardized and fast dose calculations for brachytherapy treatment planning. PURPOSE Monte Carlo TG-43 dosimetry parameters are commonly derived to characterize novel brachytherapy sources. RapidBrachyTG43 is a module of RapidBrachyMCTPS, a Monte Carlo-based treatment planning system, designed to automate this process, requiring minimal user input to prepare Geant4-based Monte Carlo simulations for a source. RapidBrachyTG43 may also perform a TG-43 dose to water-in-water calculation for a plan, substantially accelerating the same calculation performed using RapidBrachyMCTPS's Monte Carlo dose calculation engine. METHODS TG-43 parametersS K / A $S_K/A$ , Λ $\Lambda$ ,g L ( r ) $g_L(r)$ , andF ( r , θ ) $F(r,\theta)$ were calculated using three commercial source models, one each of125 $^{125}$ I,192 $^{192}$ Ir, and60 $^{60}$ Co, and were benchmarked to published data. TG-43 dose to water was calculated for a clinical breast brachytherapy plan and was compared to a Monte Carlo dose calculation with all patient tissues, air, and catheters set to water. RESULTS TG-43 parameters for the three simulated sources agreed with benchmark datasets within tolerances specified by the High Energy Brachytherapy Dosimetry working group. A gamma index comparison between the TG-43 and Monte Carlo dose-to-water calculations with a dose difference and difference to agreement criterion of 1%/1 mm yielded a 98.9% pass rate, with all relevant dose volume histogram metrics for the plan agreeing within 1%. Performing a TG-43-based dose calculation provided an acceleration of dose-to-water calculation by a factor of 165. CONCLUSIONS Determination of TG-43 parameter data for novel brachytherapy sources may now be facilitated by RapidBrachyMCTPS. These parameter datasets and existing consensus or published datasets may also be used to determine the TG-43 dose for a plan in RapidBrachyMCTPS.
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Affiliation(s)
- Jonathan Kalinowski
- Medical Physics Unit, Faculty of Medicine, Department of Oncology, McGill University, Montréal, Québec, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada
| | - Shirin A Enger
- Medical Physics Unit, Faculty of Medicine, Department of Oncology, McGill University, Montréal, Québec, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada
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Berumen F, Ouellet S, Enger S, Beaulieu L. Aleatoric and epistemic uncertainty extraction of patient-specific deep learning-based dose predictions in LDR prostate brachytherapy. Phys Med Biol 2024; 69:085026. [PMID: 38484398 DOI: 10.1088/1361-6560/ad3418] [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: 10/30/2023] [Accepted: 03/14/2024] [Indexed: 04/10/2024]
Abstract
Objective.In brachytherapy, deep learning (DL) algorithms have shown the capability of predicting 3D dose volumes. The reliability and accuracy of such methodologies remain under scrutiny for prospective clinical applications. This study aims to establish fast DL-based predictive dose algorithms for low-dose rate (LDR) prostate brachytherapy and to evaluate their uncertainty and stability.Approach.Data from 200 prostate patients, treated with125I sources, was collected. The Monte Carlo (MC) ground truth dose volumes were calculated with TOPAS considering the interseed effects and an organ-based material assignment. Two 3D convolutional neural networks, UNet and ResUNet TSE, were trained using the patient geometry and the seed positions as the input data. The dataset was randomly split into training (150), validation (25) and test (25) sets. The aleatoric (associated with the input data) and epistemic (associated with the model) uncertainties of the DL models were assessed.Main results.For the full test set, with respect to the MC reference, the predicted prostateD90metric had mean differences of -0.64% and 0.08% for the UNet and ResUNet TSE models, respectively. In voxel-by-voxel comparisons, the average global dose difference ratio in the [-1%, 1%] range included 91.0% and 93.0% of voxels for the UNet and the ResUNet TSE, respectively. One forward pass or prediction took 4 ms for a 3D dose volume of 2.56 M voxels (128 × 160 × 128). The ResUNet TSE model closely encoded the well-known physics of the problem as seen in a set of uncertainty maps. The ResUNet TSE rectum D2cchad the largest uncertainty metric of 0.0042.Significance.The proposed DL models serve as rapid dose predictors that consider the patient anatomy and interseed attenuation effects. The derived uncertainty is interpretable, highlighting areas where DL models may struggle to provide accurate estimations. The uncertainty analysis offers a comprehensive evaluation tool for dose predictor model assessment.
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Affiliation(s)
- Francisco Berumen
- Service de Physique Médicale et de Radioprotection, Centre Intégré de Cancérologie, CHU de Québec-Université Laval et Centre de recherche du CHU de Québec, Quebec, Quebec, Canada
- Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Quebec, Quebec, Canada
| | - Samuel Ouellet
- Service de Physique Médicale et de Radioprotection, Centre Intégré de Cancérologie, CHU de Québec-Université Laval et Centre de recherche du CHU de Québec, Quebec, Quebec, Canada
- Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Quebec, Quebec, Canada
| | - Shirin Enger
- Medical Physics Unit, Department of Oncology, McGill University, Montreal, Quebec, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
| | - Luc Beaulieu
- Service de Physique Médicale et de Radioprotection, Centre Intégré de Cancérologie, CHU de Québec-Université Laval et Centre de recherche du CHU de Québec, Quebec, Quebec, Canada
- Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Quebec, Quebec, Canada
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Fletcher EM, Ballester F, Beaulieu L, Morrison H, Poher A, Rivard MJ, Sloboda RS, Vijande J, Thomson RM. Generation and comparison of 3D dosimetric reference datasets for COMS eye plaque brachytherapy using model-based dose calculations. Med Phys 2024; 51:694-706. [PMID: 37665982 DOI: 10.1002/mp.16721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 08/06/2023] [Accepted: 08/15/2023] [Indexed: 09/06/2023] Open
Abstract
PURPOSE A joint Working Group of the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy and Oncology (ESTRO), and the Australasian Brachytherapy Group (ABG) was created to aid in the transition from the AAPM TG-43 dose calculation formalism, the current standard, to model-based dose calculations. This work establishes the first test cases for low-energy photon-emitting brachytherapy using model-based dose calculation algorithms (MBDCAs). ACQUISITION AND VALIDATION METHODS Five test cases are developed: (1) a single model 6711 125 I brachytherapy seed in water, 13 seeds (2) individually and (3) in combination in water, (4) the full Collaborative Ocular Melanoma Study (COMS) 16 mm eye plaque in water, and (5) the full plaque in a realistic eye phantom. Calculations are done with four Monte Carlo (MC) codes and a research version of a commercial treatment planning system (TPS). For all test cases, local agreement of MC codes was within ∼2.5% and global agreement was ∼2% (4% for test case 5). MC agreement was within expected uncertainties. Local agreement of TPS with MC was within 5% for test case 1 and ∼20% for test cases 4 and 5, and global agreement was within 0.4% for test case 1 and 10% for test cases 4 and 5. DATA FORMAT AND USAGE NOTES Dose distributions for each set of MC and TPS calculations are available online (https://doi.org/10.52519/00005) along with input files and all other information necessary to repeat the calculations. POTENTIAL APPLICATIONS These data can be used to support commissioning of MBDCAs for low-energy brachytherapy as recommended by TGs 186 and 221 and AAPM Report 372. This work additionally lays out a sample framework for the development of test cases that can be extended to other applications beyond eye plaque brachytherapy.
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Affiliation(s)
- Elizabeth M Fletcher
- Carleton Laboratory for Radiotherapy Physics, Physics Department, Carleton University, Ottawa, Ontario, Canada
| | - Facundo Ballester
- Departamento de Física Atómica, Molecular y Nuclear, Universitat de Valencia (UV), Burjassot, Spain
- Unidad Mixta de Investigación en Radiofísica e Instrumentación Nuclear en Medicina (IRIMED), Instituto de Investigación Sanitaria La Fe (IIS-La Fe)-Universitat de Valencia (UV), Burjassot, Spain
| | - Luc Beaulieu
- Service de physique médicale et Axe oncologie du Centre de recherche du CHU de Québec, CHU de Québec, Québec, Québec, Canada
- Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec, Québec, Canada
| | - Hali Morrison
- Department of Oncology and Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada
- Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta, Canada
| | - Audran Poher
- Service de physique médicale et Axe oncologie du Centre de recherche du CHU de Québec, CHU de Québec, Québec, Québec, Canada
- Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec, Québec, Canada
| | - Mark J Rivard
- Department of Radiation Oncology, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Ron S Sloboda
- Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Javier Vijande
- Departamento de Física Atómica, Molecular y Nuclear, Universitat de Valencia (UV), Burjassot, Spain
- Unidad Mixta de Investigación en Radiofísica e Instrumentación Nuclear en Medicina (IRIMED), Instituto de Investigación Sanitaria La Fe (IIS-La Fe)-Universitat de Valencia (UV), Burjassot, Spain
- Instituto de Física Corpuscular, IFIC (UV-CSIC), Burjassot, Spain
| | - Rowan M Thomson
- Carleton Laboratory for Radiotherapy Physics, Physics Department, Carleton University, Ottawa, Ontario, Canada
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Ouellet S, Lemaréchal Y, Berumen-Murillo F, Lavallée MC, Vigneault É, Martin AG, Foster W, Thomson RM, Després P, Beaulieu L. A Monte Carlo dose recalculation pipeline for durable datasets: an I-125 LDR prostate brachytherapy use case. Phys Med Biol 2023; 68:235001. [PMID: 37863069 DOI: 10.1088/1361-6560/ad058b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/20/2023] [Indexed: 10/22/2023]
Abstract
Monte Carlo (MC) dose datasets are valuable for large-scale dosimetric studies. This work aims to build and validate a DICOM-compliant automated MC dose recalculation pipeline with an application to the production of I-125 low dose-rate prostate brachytherapy MC datasets. Built as a self-contained application, the recalculation pipeline ingested clinical DICOM-RT studies, reproduced the treatment into the Monte Carlo simulation, and outputted a traceable and durable dose distribution in the DICOM dose format. MC simulations with TG43-equivalent conditions using both TOPAS andegs_brachyMC codes were compared to TG43 calculations to validate the pipeline. The consistency of the pipeline when generating TG186 simulations was measured by comparing simulations made with both MC codes. Finally,egs_brachysimulations were run on a 240-patient cohort to simulate a large-scale application of the pipeline. Compared to line source TG43 calculations, simulations with both MC codes had more than 90% of voxels with a global difference under ±1%. Differences of 2.1% and less were seen in dosimetric indices when comparing TG186 simulations from both MC codes. The large-scale comparison ofegs_brachysimulations with treatment planning system dose calculation seen the same dose overestimation of TG43 calculations showed in previous studies. The MC dose recalculation pipeline built and validated against TG43 calculations in this work efficiently produced durable MC dose datasets. Since the dataset could reproduce previous dosimetric studies within 15 h at a rate of 20 cases per 25 min, the pipeline is a promising tool for future large-scale dosimetric studies.
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Affiliation(s)
- Samuel Ouellet
- Département de physique, de génie physique et d'optique, et Centre de recherche sur le cancer, Université Laval, Québec, Québec, Canada
- Service de radio-oncologie et Axe Oncologie du CRCHU de Québec, CHU de Québec-Université Laval, Quebec, QC, Canada
| | - Yannick Lemaréchal
- Département de physique, de génie physique et d'optique, et Centre de recherche sur le cancer, Université Laval, Québec, Québec, Canada
- Service de radio-oncologie et Axe Oncologie du CRCHU de Québec, CHU de Québec-Université Laval, Quebec, QC, Canada
| | - Francisco Berumen-Murillo
- Département de physique, de génie physique et d'optique, et Centre de recherche sur le cancer, Université Laval, Québec, Québec, Canada
- Service de radio-oncologie et Axe Oncologie du CRCHU de Québec, CHU de Québec-Université Laval, Quebec, QC, Canada
| | - Marie-Claude Lavallée
- Département de physique, de génie physique et d'optique, et Centre de recherche sur le cancer, Université Laval, Québec, Québec, Canada
- Service de radio-oncologie et Axe Oncologie du CRCHU de Québec, CHU de Québec-Université Laval, Quebec, QC, Canada
| | - Éric Vigneault
- Service de radio-oncologie et Axe Oncologie du CRCHU de Québec, CHU de Québec-Université Laval, Quebec, QC, Canada
| | - André-Guy Martin
- Service de radio-oncologie et Axe Oncologie du CRCHU de Québec, CHU de Québec-Université Laval, Quebec, QC, Canada
| | - William Foster
- Service de radio-oncologie et Axe Oncologie du CRCHU de Québec, CHU de Québec-Université Laval, Quebec, QC, Canada
| | - Rowan M Thomson
- Carleton Laboratory for Radiotherapy Physics, Department of Physics, Carleton University, Ottawa, Ontario, Canada
| | - Philippe Després
- Département de physique, de génie physique et d'optique, et Centre de recherche sur le cancer, Université Laval, Québec, Québec, Canada
- Service de radio-oncologie et Axe Oncologie du CRCHU de Québec, CHU de Québec-Université Laval, Quebec, QC, Canada
| | - Luc Beaulieu
- Département de physique, de génie physique et d'optique, et Centre de recherche sur le cancer, Université Laval, Québec, Québec, Canada
- Service de radio-oncologie et Axe Oncologie du CRCHU de Québec, CHU de Québec-Université Laval, Quebec, QC, Canada
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Oliver S, Giménez-Alventosa V, Berumen F, Gimenez V, Beaulieu L, Ballester F, Vijande J. Benchmark of the PenRed Monte Carlo framework for HDR brachytherapy. Z Med Phys 2023; 33:511-528. [PMID: 36509574 PMCID: PMC10751717 DOI: 10.1016/j.zemedi.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 09/28/2022] [Accepted: 11/02/2022] [Indexed: 12/13/2022]
Abstract
PURPOSE The purpose of this study is to validate the PenRed Monte Carlo framework for clinical applications in brachytherapy. PenRed is a C++ version of Penelope Monte Carlo code with additional tallies and utilities. METHODS AND MATERIALS Six benchmarking scenarios are explored to validate the use of PenRed and its improved bachytherapy-oriented capabilities for HDR brachytherapy. A new tally allowing the evaluation of collisional kerma for any material using the track length kerma estimator and the possibility to obtain the seed positions, weights and directions processing directly the DICOM file are now implemented in the PenRed distribution. The four non-clinical test cases developed by the Joint AAPM-ESTRO-ABG-ABS WG-DCAB were evaluated by comparing local and global absorbed dose differences with respect to established reference datasets. A prostate and a palliative lung cases, were also studied. For them, absorbed dose ratios, global absorbed dose differences, and cumulative dose-volume histograms were obtained and discussed. RESULTS The air-kerma strength and the dose rate constant corresponding to the two sources agree with the reference datatests within 0.3% (Sk) and 0.1% (Λ). With respect to the first three WG-DCAB test cases, more than 99.8% of the voxels present local (global) differences within ±1%(±0.1%) of the reference datasets. For test Case 4 reference dataset, more than 94.9%(97.5%) of voxels show an agreement within ±1%(±0.1%), better than similar benchmarking calculations in the literature. The track length kerma estimator scorer implemented increases the numerical efficiency of brachytherapy calculations two orders of magnitude, while the specific brachytherapy source allows the user to avoid the use of error-prone intermediate steps to translate the DICOM information into the simulation. In both clinical cases, only minor absorbed dose differences arise in the low-dose isodoses. 99.8% and 100% of the voxels have a global absorbed dose difference ratio within ±0.2% for the prostate and lung cases, respectively. The role played by the different segmentation and composition material in the bone structures was discussed, obtaining negligible absorbed dose differences. Dose-volume histograms were in agreement with the reference data. CONCLUSIONS PenRed incorporates new tallies and utilities and has been validated for its use for detailed and precise high-dose-rate brachytherapy simulations.
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Affiliation(s)
- Sandra Oliver
- Instituto de Seguridad Industrial, Radiofísica y Medioambiental (ISIRYM), Universitat Politècnica de València, Camí de Vera s/n, 46022 València, Spain.
| | - Vicent Giménez-Alventosa
- Escuela de Ciencias, Ingeniería y Diseño, Universidad Europea de Valencia, Paseo de la Alameda 7, 46010 València, Spain; Instituto de Instrumentación para Imagen Molecular (I3M), Centro mixto CSIC - Universitat Politècnica de València, Camí de Vera s/n, 46022 València, Spain
| | - Francisco Berumen
- Département de Radio-Oncologie et Axe oncologie du Centre de recherche du CHU de Québec, CHU de Québec, Québec, QC, Canada; Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec, QC, Canada
| | - Vicente Gimenez
- Departament de Física Teórica and IFIC, Universitat de València-CSIC, Dr. Moliner, 50, 46100 Burjassot, València, Spain
| | - Luc Beaulieu
- Département de Radio-Oncologie et Axe oncologie du Centre de recherche du CHU de Québec, CHU de Québec, Québec, QC, Canada; Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec, QC, Canada
| | - Facundo Ballester
- Departamento de Física Atómica, Molecular y Nuclear. IRIMED, IIS-La Fe-Universitat de Valencia, 46100 Burjassot, Spain
| | - Javier Vijande
- Departamento de Física Atómica, Molecular y Nuclear. IRIMED, IIS-La Fe-Universitat de Valencia, 46100 Burjassot, Spain; Instituto de Física Corpuscular, IFIC (UV-CSIC), 46100 Burjassot, Spain
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Kiseleva M, Lescot T, Selivanova SV, Fortin MA. Gold-Enhanced Brachytherapy by a Nanoparticle-Releasing Hydrogel and 3D-Printed Subcutaneous Radioactive Implant Approach. Adv Healthc Mater 2023; 12:e2300305. [PMID: 37094373 DOI: 10.1002/adhm.202300305] [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: 01/29/2023] [Revised: 04/18/2023] [Indexed: 04/26/2023]
Abstract
Brachytherapy (BT) is a widely used clinical procedure for localized cervical cancer treatment. In addition, gold nanoparticles (AuNPs) have been demonstrated as powerful radiosensitizers in BT procedures. Prior to irradiation by a BT device, their delivery to tumors can enhance the radiation effect by generating low-energy photons and electrons, leading to reactive oxygen species (ROS) production, lethal to cells. No efficient delivery system has been proposed until now for AuNP topical delivery to localized cervical cancer in the context of BT. This article reports an original approach developed to accelerate the preclinical studies of AuNP-enhanced BT procedures. First, an AuNP-containing hydrogel (Pluronic F127, alginate) is developed and tested in mice for degradation, AuNP release, and biocompatibility. Then, custom-made 3D-printed radioactive BT inserts covered with a AuNP-containing hydrogel cushion are designed and administered by surgery in mice (HeLa xenografts), which allows for measuring AuNP penetration in tumors (≈100 µm), co-registered with the presence of ROS produced through the interactions of radiation and AuNPs. Biocompatible AuNPs-releasing hydrogels could be used in the treatment of cervical cancer prior to BT, with impact on the total amount of radiation needed per BT treatment, which will result in benefits to the preservation of healthy tissues surrounding cancer.
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Affiliation(s)
- Mariia Kiseleva
- Département de Génie des Mines, de la Métallurgie et des Matériaux, Centre de Recherche sur les Matériaux Avancés (CERMA), Université Laval, Québec, G1V 0A6, Canada
- Laboratoire de Biomatériaux pour l'Imagerie Médicale, Axe Médecine Régénératrice, Centre de Recherche du CHU de Québec - Université Laval, Québec, G1V 4G2, Canada
| | - Théophraste Lescot
- Département de Génie des Mines, de la Métallurgie et des Matériaux, Centre de Recherche sur les Matériaux Avancés (CERMA), Université Laval, Québec, G1V 0A6, Canada
- Laboratoire de Biomatériaux pour l'Imagerie Médicale, Axe Médecine Régénératrice, Centre de Recherche du CHU de Québec - Université Laval, Québec, G1V 4G2, Canada
| | - Svetlana V Selivanova
- Faculty of Pharmacy, Université Laval, Québec, G1V 0A6, Canada
- Axe Oncologie, Centre de Recherche du CHU de Québec - Université Laval, Québec, G1R 3S3, Canada
| | - Marc-André Fortin
- Département de Génie des Mines, de la Métallurgie et des Matériaux, Centre de Recherche sur les Matériaux Avancés (CERMA), Université Laval, Québec, G1V 0A6, Canada
- Laboratoire de Biomatériaux pour l'Imagerie Médicale, Axe Médecine Régénératrice, Centre de Recherche du CHU de Québec - Université Laval, Québec, G1V 4G2, Canada
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Walter AE, Khan AU, DeWerd LA. Measurement of the modified TG43 parameters for the bare S7600 Xoft Axxent source model. Brachytherapy 2023; 22:260-268. [PMID: 36623989 DOI: 10.1016/j.brachy.2022.11.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 11/16/2022] [Accepted: 11/22/2022] [Indexed: 01/09/2023]
Abstract
PURPOSE The purpose of this work is to provide measured data for the modified TG43 parameters [DeWerd et al.] for the newest, Galden-cooled S7600 Xoft Axxent source model. METHODS The measurement of radial dose distributions at distances of 1 cm to 4 cm from the source was performed using TLD100 microcubes, EBT3 film, and an Exradin A26 microionization chamber. The overall uncertainty and reproducibility of each dosimeter was evaluated for its use in determining the radial dose function and dose rate conversion coefficient. An acrylic phantom developed in house for previous works was used to measure the polar anisotropy function using TLD100 microcubes at distances of 1 cm, 2 cm, and 5 cm from the source. RESULTS The Exradin A26 chamber was deemed most suitable for measuring the radial dose function. Values determined had a maximum k = 1 uncertainty of 1.4%. The dose rate conversion coefficient measured with the chamber was found to be 9.33 ± 0.21cGy/hrμGy/min. TLD100 microcube measurements of the polar anisotropy had average uncertainties of 6%, 3%, and 2.5% at 1 cm, 2 cm, and 5 cm, respectively. CONCLUSIONS The modified TG43 parameters for the bare source were measured with reasonable uncertainty. The values determined will aid with the clinical implementation of the source for breast and endometrial cancer applications.
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Affiliation(s)
- Autumn E Walter
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, WI; Department of Human Oncology, School of Medicine and Public Health, University of Wisconsin, Madison, WI.
| | - Ahtesham U Khan
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, WI
| | - Larry A DeWerd
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, WI
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Poher A, Berumen F, Ma Y, Perl J, Beaulieu L. Validation of the TOPAS Monte Carlo toolkit for LDR brachytherapy simulations. Phys Med 2023; 107:102516. [PMID: 36804693 DOI: 10.1016/j.ejmp.2022.102516] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 11/07/2022] [Accepted: 12/27/2022] [Indexed: 02/18/2023] Open
Abstract
PURPOSE This work has the purpose of validating the Monte Carlo toolkit TOol for PArticle Simulation (TOPAS) for low-dose-rate (LDR) brachytherapy uses. METHODS AND MATERIALS Simulations of 12 LDR sources and 2 COMS eye plaques (10 mm and 20 mm in diameter) and comparisons with published reference data from the Carleton Laboratory for Radiotherapy Physics (CLRP), the TG-43 consensus data and the TG-129 consensus data were performed. Sources from the IROC Houston Source Registry were modeled. The OncoSeed 6711 and the SelectSeed 130.002 were also modeled for historical reasons. For each source, the dose rate constant, the radial dose function and the anisotropy functions at 0.5, 1 and 5 cm were extracted. For the eye plaques (loaded with 125I sources), dose distribution maps, dose profiles along the central axis and transverse axis were calculated. RESULTS Dose rate constants for 11 of the 12 sources are within 4% of the consensus data and within 2% of the CLRP data. The radial dose functions and anisotropy functions are mostly within 2% of the CLRP data. In average, 92% of all voxels are within 1% of the CLRP data for the eye plaques dose distributions. The dose profiles are within 0.5% (central axis) and 1% (transverse axis) of the reference data. CONCLUSION The TOPAS MC toolkit was validated for LDR brachytherapy applications. Single-seed and multi-seed results agree with the published reference data. TOPAS has several benefits such as a simplified approach to MC simulations and an accessible brachytherapy package including comprehensive learning resources.
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Affiliation(s)
- Audran Poher
- Service de physique médicale et de radioprotection, Centre Intégré de Cancérologie, CHU de Québec - Université Laval et Centre de recherche du CHU de Québec, Québec, Québec, Canada; Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec Québec G1V 0A6, Canada.
| | - Francisco Berumen
- Service de physique médicale et de radioprotection, Centre Intégré de Cancérologie, CHU de Québec - Université Laval et Centre de recherche du CHU de Québec, Québec, Québec, Canada; Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec Québec G1V 0A6, Canada
| | - Yunzhi Ma
- Service de physique médicale et de radioprotection, Centre Intégré de Cancérologie, CHU de Québec - Université Laval et Centre de recherche du CHU de Québec, Québec, Québec, Canada; Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec Québec G1V 0A6, Canada
| | - Joseph Perl
- SLAC National Accelerator Laboratory, Menlo Park, CA, United States of America
| | - Luc Beaulieu
- Service de physique médicale et de radioprotection, Centre Intégré de Cancérologie, CHU de Québec - Université Laval et Centre de recherche du CHU de Québec, Québec, Québec, Canada; Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec Québec G1V 0A6, Canada
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Monte-Carlo techniques for radiotherapy applications II: equipment and source modelling, dose calculations and radiobiology. JOURNAL OF RADIOTHERAPY IN PRACTICE 2023. [DOI: 10.1017/s1460396923000080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
Abstract
Introduction:
This is the second of two papers giving an overview of the use of Monte-Carlo techniques for radiotherapy applications.
Methods:
The first paper gave an introduction and introduced some of the codes that are available to the user wishing to model the different aspects of radiotherapy treatment. It also aims to serve as a useful companion to a curated collection of papers on Monte-Carlo that have been published in this journal.
Results and Conclusions:
This paper focuses on the application of Monte-Carlo to specific problems in radiotherapy. These include radiotherapy and imaging beam production, brachytherapy, phantom and patient dosimetry, detector modelling and track structure calculations for micro-dosimetry, nano-dosimetry and radiobiology.
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Insley B, Goldberg K, Beaulieu L, Ma Y, McKinley S, Hsu IC, Cunha JA. Comparison of novel shielded nasopharynx applicator designs for intracavitary brachytherapy. Brachytherapy 2022; 21:229-237. [DOI: 10.1016/j.brachy.2021.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 12/18/2021] [Accepted: 12/20/2021] [Indexed: 11/02/2022]
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Bertolet A, Wehrenberg-Klee E, Bobić M, Grassberger C, Perl J, Paganetti H, Schuemann J. Pre- and post-treatment image-based dosimetry in 90Y-microsphere radioembolization using the TOPAS Monte Carlo toolkit. Phys Med Biol 2021; 66:10.1088/1361-6560/ac43fd. [PMID: 34915451 PMCID: PMC8729171 DOI: 10.1088/1361-6560/ac43fd] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/16/2021] [Indexed: 12/31/2022]
Abstract
Objective. To evaluate the pre-treatment and post-treatment imaging-based dosimetry of patients treated with 90Y-microspheres, including accurate estimations of dose to tumor, healthy liver and lung. To do so, the Monte Carlo (MC) TOPAS platform is in this work extended towards its utilization in radionuclide therapy.Approach. Five patients treated at the Massachusetts General Hospital were selected for this study. All patients had data for both pre-treatment SPECT-CT imaging using 99mTc-MAA as a surrogate of the 90Y-microspheres treatment and SPECT-CT imaging immediately after the 90Y activity administration. Pre- and post-treatment doses were computed with TOPAS using the SPECT images to localize the source positions and the CT images to account for tissue inhomoegeneities. We compared our results with analytical calculations following the voxel-based MIRD scheme.Main results. TOPAS results largely agreed with the MIRD-based calculations in soft tissue regions: the average difference in mean dose to the liver was 0.14 Gy GBq-1(2.6%). However, dose distributions in the lung differed considerably: absolute differences in mean doses to the lung ranged from 1.2 to 6.3 Gy GBq-1and relative differences from 153% to 231%. We also found large differences in the intra-hepatic dose distributions between pre- and post-treatment imaging, but only limited differences in the pulmonary dose.Significance. Doses to lung were found to be higher using TOPAS with respect to analytical calculations which may significantly underestimate dose to the lung, suggesting the use of MC methods for 90Y dosimetry. According to our results, pre-treatment imaging may still be representative of dose to lung in these treatments.
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Affiliation(s)
- Alejandro Bertolet
- Department of Radiation Oncology, Massachusetts General Hospital
and Harvard Medical School, Boston, MA, USA
| | - Eric Wehrenberg-Klee
- Department of Radiology, Division of Interventional Radiology,
Massachusetts General Hospital, Boston, MA, USA
| | - Mislav Bobić
- Department of Radiation Oncology, Massachusetts General Hospital
and Harvard Medical School, Boston, MA, USA & Department of Physics, ETH
Zürich, Zürich, Switzerland
| | - Clemens Grassberger
- Department of Radiation Oncology, Massachusetts General Hospital
and Harvard Medical School, Boston, MA
| | - Joseph Perl
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Harald Paganetti
- Department of Radiation Oncology, Massachusetts General Hospital
and Harvard Medical School, Boston, MA, USA
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital
and Harvard Medical School, Boston, MA, USA
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