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Matrosic CK, Kronenberg S, Demirci H, Hayman JA, Han H, Lee C. A novel 3D-printed brachytherapy applicator and monte Carlo model for the treatment of conjunctival tumors. Brachytherapy 2024:S1538-4721(24)00112-0. [PMID: 39181747 DOI: 10.1016/j.brachy.2024.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 07/09/2024] [Accepted: 07/17/2024] [Indexed: 08/27/2024]
Abstract
PURPOSE To develop a custom low dose rate brachytherapy applicator for the treatment of conjunctival malignancies which leverages 3D-printing technology to provide enhanced design flexibility and availability. METHODS An elliptical shell applicator inspired by ocular surgery postoperation conformer shells was developed for the placement of the applicator around the cornea of the eye, with a central hole to provide patient comfort. The applicator featured 2 concentric circles of slots for iodine-125 seeds, providing customization of the dose distribution depending on the location of the target. The applicator was modeled using computer-aided design software. The resultant model STL file was used for 3D printing of the applicator and the development of a Monte Carlo model of the applicator and its dose distribution. RESULTS The applicator was successfully 3D printed using biocompatible resin, which could be sterilized for treatment after manual source loading. A Geant4 model of the applicator was created directly from the STL model and was applied to a phantom to estimate the dose distribution delivered by the applicator. The toroidal dose distribution allowed for treatment of the conjunctiva while reducing dose to the cornea compared to traditional eye plaque designs. CONCLUSIONS A custom 3D-printed applicator was successfully developed and modeled for the treatment of conjunctival malignancies. This novel applicator design potentially provides higher quality, more customizable dose distributions for patients and the simplicity of the design makes it accessible for any clinic with 3D-printing technology.
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Affiliation(s)
- C K Matrosic
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI.
| | - S Kronenberg
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - H Demirci
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI
| | - J A Hayman
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - H Han
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD
| | - C Lee
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
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Fagerstrom JM. Practical experience with initial quality assurance of a high dose rate brachytherapy grid-based Boltzmann solver algorithm. J Appl Clin Med Phys 2024; 25:e14392. [PMID: 38742858 PMCID: PMC11302815 DOI: 10.1002/acm2.14392] [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: 02/01/2024] [Revised: 04/18/2024] [Accepted: 04/24/2024] [Indexed: 05/16/2024] Open
Abstract
PURPOSE The purpose of this study was to validate the use of a model-based dose calculation algorithm (MBDCA), Acuros BV, for high dose rate brachytherapy treatment planning for a community-based hospital with a Bravos afterloader. Based on published AAPM recommendations, this work details a practical approach for community-based clinics to complete initial validation of Acuros BV, in order to add a MBDCA to a TG-43 based brachytherapy treatment planning program. METHODS Source dimensions and materials used in Acuros BV and TG-43 source models were compared to the physical source. TG-186 testing was completed with standardized test cases externally calculated with Monte Carlo compared to locally calculated with Acuros BV. Point doses calculated using TG-43 were compared to those calculated with Acuros BV in water at various dose grid settings. Secondary dose check software was used to evaluate dose distributions resembling clinical patient plans, both in water and on CT datasets representative of patient anatomy. RESULTS The major source of discrepancy of source models was the length of modeled steel cable. TG-186 testing showed that the largest differences between Monte Carlo and Acuros BV dose distributions were located along the source axis for cases calculated in water, as well as located in regions of high dose gradients and within the applicator for the case calculated with a generic shielded applicator. An audit of point doses calculated with both TG-43 and Acuros BV in water found that dose grid settings significantly affected agreement. Secondary dose check software indicated that Acuros BV functioned satisfactorily, and a 5% threshold was adopted for secondary dose checks on gynecologic plans. CONCLUSION This validation process indicated that Acuros BV met expected standards and affirmed its suitability for integration into this clinical practice's brachytherapy treatment planning.
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Affiliation(s)
- Jessica M. Fagerstrom
- Department of Radiation OncologyUniversity of WashingtonSeattleWashingtonUSA
- Department of Radiation OncologyKaiser PermanenteSeattleWashingtonUSA
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Ibáñez P, Villa-Abaunza A, Udías JM. Impact on the estimated dose of different tissue assignment strategies during partial breast irradiations with INTRABEAM. Brachytherapy 2024; 23:470-477. [PMID: 38705803 DOI: 10.1016/j.brachy.2024.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 01/19/2024] [Accepted: 02/12/2024] [Indexed: 05/07/2024]
Abstract
PURPOSE Partial breast irradiations with electronic brachytherapy or kilovoltage intraoperative radiotherapy devices such as Axxent or INTRABEAM are becoming more common every day. Breast is mainly composed of glandular and adipose tissues, which are not always clearly disentangled in planning breast CTs. In these cases, breast tissues are replaced with an average soft tissue, or even water. However, at kilovoltage energies, this may lead to large differences in the delivered dose, due to the dominance of photoelectric effect. Therefore, the aim of this work was to study the effect on the dose prescribed in breast with the INTRABEAM device using different soft tissue assignment strategies that would replace the adipose and glandular tissues that constitute the breast in cases where these tissues cannot be adequately distinguished in a CT scan. METHODS AND MATERIALS Dose was computed with a Monte Carlo code in five patients with a 3 cm diameter INTRABEAM spherical applicator. Tissues within the breast were assigned following six different strategies: one based on the TG-43 recommendations, representing the whole breast as water of unity density, another one also water-based but with CT derived density, and the other four also based on CT-derived densities, using a single tissue resulting from different mixes of glandular and adipose tissues. These were compared against the reference dose computed in an accurately segmented CT, following TG-186 recommendations. Relative differences and dose ratios between the reference and the other tissue assignment strategies were obtained in three regions of interest inside the breast. RESULTS AND CONCLUSIONS Dose planning in water-based tissues was found inaccurate for breast treatment with INTRABEAM, as it would incur in up to 30% under-prescription of dose. If accurate soft tissue assignments in the breast cannot be safely done, a single-tissue composition of 80% adipose and 20% glandular tissue, or even a 100% adipose tissue, would be recommended to avoid dose under-prescription.
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Affiliation(s)
- Paula Ibáñez
- Nuclear Physics Group and IPARCOS, Department of Structure of Matter, Thermal Physics and Electronics, CEI Moncloa, Universidad Complutense de Madrid, Madrid, Spain; Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain.
| | - Amaia Villa-Abaunza
- Nuclear Physics Group and IPARCOS, Department of Structure of Matter, Thermal Physics and Electronics, CEI Moncloa, Universidad Complutense de Madrid, Madrid, Spain
| | - José Manuel Udías
- Nuclear Physics Group and IPARCOS, Department of Structure of Matter, Thermal Physics and Electronics, CEI Moncloa, Universidad Complutense de Madrid, Madrid, Spain; Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain
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Xiong T, Cai J, Zhou F, Liu B, Zhang J, Wu Q. An end-to-end deep convolutional neural network-based dose engine for parotid gland cancer seed implant brachytherapy. Med Phys 2024. [PMID: 38753975 DOI: 10.1002/mp.17123] [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: 10/30/2023] [Revised: 04/12/2024] [Accepted: 04/29/2024] [Indexed: 05/18/2024] Open
Abstract
BACKGROUND Seed implant brachytherapy (SIBT) is a promising treatment modality for parotid gland cancers (PGCs). However, the current clinical standard dose calculation method based on the American Association of Physicists in Medicine (AAPM) Task Group 43 (TG-43) Report oversimplifies patient anatomy as a homogeneous water phantom medium, leading to significant dose calculation errors due to heterogeneity surrounding the parotid gland. Monte Carlo Simulation (MCS) can yield accurate dose distributions but the long computation time hinders its wide application in clinical practice. PURPOSE This paper aims to develop an end-to-end deep convolutional neural network-based dose engine (DCNN-DE) to achieve fast and accurate dose calculation for PGC SIBT. METHODS A DCNN model was trained using the patient's CT images and TG-43-based dose maps as inputs, with the corresponding MCS-based dose maps as the ground truth. The DCNN model was enhanced based on our previously proposed model by incorporating attention gates (AGs) and large kernel convolutions. Training and evaluation of the model were performed using a dataset comprising 188 PGC I-125 SIBT patient cases, and its transferability was tested on an additional 16 non-PGC head and neck cancers (HNCs) I-125 SIBT patient cases. Comparison studies were conducted to validate the superiority of the enhanced model over the original one and compare their overall performance. RESULTS On the PGC testing dataset, the DCNN-DE demonstrated the ability to generate accurate dose maps, with percentage absolute errors (PAEs) of 0.67% ± 0.47% for clinical target volume (CTV) D90 and 1.04% ± 1.33% for skin D0.1cc. The comparison studies revealed that incorporating AGs and large kernel convolutions resulted in 8.2% (p < 0.001) and 3.1% (p < 0.001) accuracy improvement, respectively, as measured by dose mean absolute error. On the non-PGC HNC dataset, the DCNN-DE exhibited good transferability, achieving a CTV D90 PAE of 1.88% ± 1.73%. The DCNN-DE can generate a dose map in less than 10 ms. CONCLUSIONS We have developed and validated an end-to-end DCNN-DE for PGC SIBT. The proposed DCNN-DE enables fast and accurate dose calculation, making it suitable for application in the plan optimization and evaluation process of PGC SIBT.
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Affiliation(s)
- Tianyu Xiong
- Image Processing Center, Beihang University, Beijing, People's Republic of China
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong SAR, People's Republic of China
| | - Jing Cai
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong SAR, People's Republic of China
| | - Fugen Zhou
- Image Processing Center, Beihang University, Beijing, People's Republic of China
| | - Bo Liu
- Image Processing Center, Beihang University, Beijing, People's Republic of China
| | - Jie Zhang
- Department of Oral and Maxillofacial Surgery, Peking University School of Stomatology, Beijing, People's Republic of China
| | - Qiuwen Wu
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, USA
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Lee YC, Nik Akhtar M, Kim Y, Jung JW. A practical method of estimating medium-heterogeneity corrected dose without a Monte Carlo calculation in ocular brachytherapy using 125I COMS plaques. Brachytherapy 2024; 23:377-386. [PMID: 38336557 DOI: 10.1016/j.brachy.2024.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/03/2024] [Accepted: 01/04/2024] [Indexed: 02/12/2024]
Abstract
PURPOSE To provide a practical method of estimating medium-heterogeneity corrected dose without a Monte Carlo (MC) calculation in ocular brachytherapy using 125I Collaborative Ocular Melanoma Study (COMS) plaques. METHODS AND MATERIALS Using egs_brachy, MC simulations (1) under task group-43 assumptions with fully loaded seed configurations in water (HOMO) and (2) with effects of plaque backing, insert and inter-seed interactions (HETERO) were performed for seven 125I COMS plaques (10 mm-22 mm in diameter), and homogeneous dose (DHOMO) and heterogeneous dose (DHETERO) for central-axis and off-axis points were determined. For DHOMO, 85 Gy was normalized to a depth of 5 mm. Central-axis heterogeneity correction factors (HCFs) from a depth of 0 mm (inner sclera) to 22 mm (opposite retina) were derived from a ratio of DHETERO to DHOMO. Off-axis HCFs for optic disc/macula and lens as a function of distance from optic disc/macula (DT/MT) for various basal dimensions of tumor (BD/BM) were derived from DHETERO/DHOMO. RESULTS Central-axis HCF varied with a dose reduction of 10.3-19.8% by heterogeneity. Off-axis HCF for optic disc/macula varied significantly depending on DT/MT and BD/BM with a dose reduction of 11.3-38.3%. Off-axis HCF for lens had a dependence on MT and BM with its variation of 11.0-19.0%. A clinical example of using HCFs to estimate DHETERO was presented. CONCLUSIONS The practical method of using depth-dependent central-axis HCF and DT/MT- and BD/BM-dependent off-axis HCF provided in this study will facilitate a heterogeneous dose estimate for 125I COMS plaques without MC calculations.
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Affiliation(s)
- Yongsook C Lee
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, FL; Department of Radiation Oncology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL
| | | | - Yongbok Kim
- Department of Radiation Oncology, Duke University, Durham, NC.
| | - Jae Won Jung
- Department of Radiation Oncology, East Carolina University, Greenville, NC
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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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Semeniuk O, Yu E, Rivard MJ. Current and Emerging Radiotherapy Options for Uveal Melanoma. Cancers (Basel) 2024; 16:1074. [PMID: 38473430 DOI: 10.3390/cancers16051074] [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: 01/21/2024] [Revised: 03/01/2024] [Accepted: 03/04/2024] [Indexed: 03/14/2024] Open
Abstract
What treatment options are there for patients having uveal melanoma? A randomized, prospective, multi-institutional clinical trial (COMS) showed no difference in survival between brachytherapy and enucleation for medium-sized lesions. With the obvious benefit of retaining the eye, brachytherapy has flourished and many different approaches have been developed such as low-dose-rate sources using alternate low-energy photon-emitting radionuclides, different plaque designs and seed-loading techniques, high-dose-rate brachytherapy sources and applicators, and low- and high-dose-rate beta-emitting sources and applicators. There also have been developments of other radiation modalities like external-beam radiotherapy using linear accelerators with high-energy photons, particle accelerators for protons, and gamma stereotactic radiosurgery. This article examines the dosimetric properties, targeting capabilities, and outcomes of these approaches. The several modalities examined herein have differing attributes and it may be that no single approach would be considered optimal for all patients and all lesion characteristics.
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Affiliation(s)
- Oleksii Semeniuk
- Department of Radiation Oncology, Warren Alpert Medical School, Brown University and Rhode Island Hospital, Providence, RI 02903, USA
| | - Esther Yu
- Department of Radiation Oncology, Warren Alpert Medical School, Brown University and Rhode Island Hospital, Providence, RI 02903, USA
| | - Mark J Rivard
- Department of Radiation Oncology, Warren Alpert Medical School, Brown University and Rhode Island Hospital, Providence, RI 02903, USA
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Antunes PCG, Siqueira PDTD, Shorto JMB, Yoriyaz H. Heterogeneous physical phantom for I-125 dose measurements and dose-to-medium determination. Brachytherapy 2024; 23:73-84. [PMID: 38016863 DOI: 10.1016/j.brachy.2023.08.007] [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: 04/17/2023] [Revised: 07/30/2023] [Accepted: 08/30/2023] [Indexed: 11/30/2023]
Abstract
PURPOSE In this paper we present a further step in the implementation of a physical phantom designed to generate sets of "true" independent reference data as requested by TG-186, intending to address and mitigate the scarcity of experimental studies on brachytherapy (BT) validation in heterogeneous media. To achieve this, we incorporated well-known heterogeneous materials into the phantom in order to perform measurements of 125I dose distribution. The work aims to experimentally validate Monte Carlo (MC) calculations based on MBDCA and determine the conversion factors from LiF response to absorbed dose in different media, using cavity theory. METHODS AND MATERIALS The physical phantom was adjusted to incorporate tissue equivalent materials, such as: adipose tissue, bone, breast and lung with varying thickness. MC calculations were performed using MCNP6.2 code to calculate the absorbed dose in the LiF and the dose conversion factors (DCF). RESULTS The proposed heterogeneous phantom associated with the experimental procedure carried out in this work yielded accurate dose data that enabled the conversion of the LiF responses into absorbed dose to medium. The results showed a maximum uncertainty of 6.92 % (k = 1), which may be considered excellent for dosimetry with low-energy BT sources. CONCLUSIONS The presented heterogeneous phantom achieves the required precision in dose evaluations due to its easy reproducibility in the experimental setup. The obtained results support the dose conversion methodology for all evaluated media. The experimental validation of the DCF in different media holds great significance for clinical procedures, as it can be applied to other tissues, including water, which remains a widely utilized reference medium in clinical practice.
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Affiliation(s)
- Paula Cristina Guimarães Antunes
- Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, Sao Paulo, Brazil; Institute of Physics, University of Sao Paulo, Sao Paulo, Brazil.
| | | | | | - Hélio Yoriyaz
- Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, Sao Paulo, Brazil
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Oare CC, Dailey JP, Gerbi B, Ferreira C. Novel intraocular shielding device for eye plaque brachytherapy using magnetite nanoparticles: A proof-of-concept study using radiochromic film and Monte Carlo simulations. Brachytherapy 2023; 22:769-778. [PMID: 37718143 DOI: 10.1016/j.brachy.2023.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 06/24/2023] [Accepted: 07/27/2023] [Indexed: 09/19/2023]
Abstract
PURPOSE Eye plaque brachytherapy is a mainstay treatment for uveal melanomas despite potential toxicities to normal tissues. This work proposes a nanoparticle ferrofluid as a novel intraocular shielding device. With a modified magnetic plaque, the shielding particles are drawn to the tumor surface, attenuating dose beyond the tumor while maintaining prescription dose to the target. METHODS AND MATERIALS Ferromagnetic nanoparticles suspended in a silicone polymer were synthesized to provide a high-density shielding medium. The ferrofluid's half-value layer (HVL) was quantified for 125I photons using radiochromic film and Monte Carlo methods. A magnetic COMS plaque was created and evaluated in its ability to attract ferrofluid over the tumor. Two ferrofluid shielding mediums were evaluated in their ability to attenuate dose at adjacent structures with in vitro measurements using radiochromic film, in addition to Monte Carlo studies. RESULTS The shielding medium's HVL measured approximately 1.3 mm for an 125I photon spectrum, using film and Monte Carlo methods. With 0.8 mL of shielding medium added to the vitreous humor, it proved to be effective at reducing dose to normal tissues of the eye. Monte Carlo-calculated dose reductions of 65%, 80%, and 78% at lateral distances 5, 10, and 18 mm from a tumor (5-mm apical height) in a modeled 20-mm COMS plaque. CONCLUSIONS The magnitude of dose reduction could reduce the likelihood of normal tissue side effects for plaque brachytherapy patients, including patients with normal tissues close to the plaque or tumor. Additional studies, safety considerations, and preclinical work must supplement these findings before use.
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Affiliation(s)
| | | | - Bruce Gerbi
- University of Minnesota Medical School, Minneapolis, MN
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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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Akino Y, Shiomi H, Tsujimoto T, Hamatani N, Hirata T, Oda M, Takeshita A, Shimamoto H, Ogawa K, Murakami S. Inverse planning optimization with lead block effectively suppresses dose to the mandible in high-dose-rate brachytherapy for tongue cancer. Jpn J Radiol 2023; 41:1290-1297. [PMID: 37273111 PMCID: PMC10613594 DOI: 10.1007/s11604-023-01451-w] [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: 02/22/2023] [Accepted: 05/14/2023] [Indexed: 06/06/2023]
Abstract
PURPOSE In this study, we developed in-house software to evaluate the effect of the lead block (LB)-inserted spacer on the mandibular dose in interstitial brachytherapy (ISBT) for tongue cancer. In addition, an inverse planning algorithm for LB attenuation was developed, and its performance in mandibular dose reduction was evaluated. METHODS Treatment plans of 30 patients with tongue cancer treated with ISBT were evaluated. The prescribed dose was 54 Gy/9 fractions. An in-house software was developed to calculate the dose distribution based on the American Association of Physicists in Medicine (AAPM) Task Group No.43 (TG-43) formalism. The mandibular dose was calculated with consideration of the LB attenuation. The attenuation coefficient of the lead was computed using the PHITS Monte Carlo simulation. The software further optimized the treatment plans using an attraction-repulsion model (ARM) to account for the LB attenuation. RESULTS Compared to the calculation in water, the D2 cc of the mandible changed by - 2.4 ± 2.3 Gy (range, - 8.6 to - 0.1 Gy) when the LB attenuation was considered. The ARM optimization with consideration of the LB resulted in a - 2.4 ± 2.4 Gy (range, - 8.2 to 0.0 Gy) change in mandibular D2 cc. CONCLUSIONS This study enabled the evaluation of the dose distribution with consideration of the LB attenuation. The ARM optimization with lead attenuation further reduced the mandibular dose.
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Affiliation(s)
- Yuichi Akino
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan.
- Department of Oral and Maxillofacial Radiology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
| | - Hiroya Shiomi
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan
- Department of Oral and Maxillofacial Radiology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Tomomi Tsujimoto
- Department of Oral and Maxillofacial Radiology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Noriaki Hamatani
- Department of Medical Physics, Osaka Heavy-Ion Therapy Center, Osaka, Japan
| | - Takero Hirata
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Michio Oda
- Department of Medical Technology, Osaka University Hospital, Suita, Osaka, Japan
| | - Ami Takeshita
- Department of Oral and Maxillofacial Radiology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Hiroaki Shimamoto
- Department of Oral and Maxillofacial Radiology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Kazuhiko Ogawa
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Shumei Murakami
- Department of Oral and Maxillofacial Radiology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
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Frank CH, Ramesh P, Lyu Q, Ruan D, Park SJ, Chang AJ, Venkat PS, Kishan AU, Sheng K. Analytical HDR prostate brachytherapy planning with automatic catheter and isotope selection. Med Phys 2023; 50:6525-6534. [PMID: 37650773 PMCID: PMC10635680 DOI: 10.1002/mp.16677] [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: 10/12/2022] [Revised: 06/27/2023] [Accepted: 07/30/2023] [Indexed: 09/01/2023] Open
Abstract
BACKGROUND High dose rate (HDR) brachytherapy is commonly used to treat prostate cancer. Existing HDR planning systems solve the dwell time problem for predetermined catheters and a single energy source. PURPOSE Additional degrees of freedom can be obtained by relaxing the catheters' pre-designation and introducing more source types, and may have a dosimetric benefit, particularly in improving conformality to spare the urethra. This study presents a novel analytical approach to solving the corresponding HDR planning problem. METHODS The catheter and dual-energy source selection problem was formulated as a constrained optimization problem with a non-convex group sparsity regularization. The optimization problem was solved using the fast-iterative shrinkage-thresholding algorithm (FISTA). Two isotopes were considered. The dose rates for the HDR 4140 Ytterbium (Yb-169) source and the Elekta Iridium (Ir-192) HDR Flexisource were modeled according to the TG-43U1 formalism and benchmarked accordingly. Twenty-two retrospective HDR prostate brachytherapy patients treated with Ir-192 were considered. An Ir-192 only (IRO), Yb-169 only (YBO), and dual-source (DS) plan with optimized catheter location was created for each patient with N catheters, where N is the number of catheters used in the clinically delivered plans. The DS plans jointly optimized Yb-169 and Ir-192 dwell times. All plans and the clinical plans were normalized to deliver a 15 Gy prescription (Rx) dose to 95% of the clinical treatment volume (CTV) and evaluated for the CTV D90%, V150%, and V200%, urethra D0.1cc and D1cc, bladder V75%, and rectum V75%. Dose-volume histograms (DVHs) were generated for each structure. RESULTS The DS plans ubiquitously selected Ir-192 as the only treatment source. IRO outperformed YBO in organ at risk (OARs) OAR sparing, reducing the urethra D0.1cc and D1cc by 0.98% (p = 2.22 ∗ 10 - 9 $p\ = \ 2.22*{10^{ - 9}}$ ) and 1.09% (p = 1.22 ∗ 10 - 10 $p\ = \ 1.22*{10^{ - 10}}$ ) of the Rx dose, respectively, and reducing the bladder and rectum V75% by 0.09 (p = 0.0023 $p\ = \ 0.0023$ ) and 0.13 cubic centimeters (cc) (p = 0.033 $p\ = \ 0.033$ ), respectively. The YBO plans delivered a more homogenous dose to the CTV, with a smaller V150% and V200% by 3.20 (p = 4.67 ∗ 10 - 10 $p\ = \ 4.67*{10^{ - 10}}$ ) and 1.91 cc (p = 5.79 ∗ 10 - 10 $p\ = \ 5.79*{10^{ - 10}}$ ), respectively, and a lower CTV D90% by 0.49% (p = 0.0056 $p\ = \ 0.0056$ ) of the prescription dose. The IRO plans reduce the urethral D1cc by 2.82% (p = 1.38 ∗ 10 - 4 $p\ = \ 1.38*{10^{ - 4}}$ ) of the Rx dose compared to the clinical plans, at the cost of increased bladder and rectal V75% by 0.57 (p = 0.0022 $p\ = \ 0.0022$ ) and 0.21 cc (p = 0.019 $p\ = \ 0.019$ ), respectively, and increased CTV V150% by a mean of 1.46 cc (p = 0.010 $p\ = \ 0.010$ ) and CTV D90% by an average of 1.40% of the Rx dose (p = 8.80 ∗ 10 - 8 $p\ = \ 8.80*{10^{ - 8}}$ ). While these differences are statistically significant, the clinical differences between the plans are minimal. CONCLUSIONS The proposed analytical HDR planning algorithm integrates catheter and isotope selection with dwell time optimization for varying clinical goals, including urethra sparing. The planning method can guide HDR implants and identify promising isotopes for specific HDR clinical goals, such as target conformality or OAR sparing.
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Affiliation(s)
- Catherine Holly Frank
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095
| | - Pavitra Ramesh
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095
| | - Qihui Lyu
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095
| | - Dan Ruan
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095
| | - Sang-June Park
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095
| | - Albert J. Chang
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095
| | - Puja S. Venkat
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095
| | - Amar U. Kishan
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095
| | - Ke Sheng
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA 94115
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14
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Beaulieu L, Ballester F, Granero D, Tedgren ÅC, Haworth A, Lowenstein JR, Ma Y, Mourtada F, Papagiannis P, Rivard MJ, Siebert FA, Sloboda RS, Smith RL, Thomson RM, Verhaegen F, Fonseca G, Vijande J. AAPM WGDCAB Report 372: A joint AAPM, ESTRO, ABG, and ABS report on commissioning of model-based dose calculation algorithms in brachytherapy. Med Phys 2023; 50:e946-e960. [PMID: 37427750 DOI: 10.1002/mp.16571] [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: 10/03/2022] [Revised: 02/16/2023] [Accepted: 04/24/2023] [Indexed: 07/11/2023] Open
Abstract
The introduction of model-based dose calculation algorithms (MBDCAs) in brachytherapy provides an opportunity for a more accurate dose calculation and opens the possibility for novel, innovative treatment modalities. The joint AAPM, ESTRO, and ABG Task Group 186 (TG-186) report provided guidance to early adopters. However, the commissioning aspect of these algorithms was described only in general terms with no quantitative goals. This report, from the Working Group on Model-Based Dose Calculation Algorithms in Brachytherapy, introduced a field-tested approach to MBDCA commissioning. It is based on a set of well-characterized test cases for which reference Monte Carlo (MC) and vendor-specific MBDCA dose distributions are available in a Digital Imaging and Communications in Medicine-Radiotherapy (DICOM-RT) format to the clinical users. The key elements of the TG-186 commissioning workflow are now described in detail, and quantitative goals are provided. This approach leverages the well-known Brachytherapy Source Registry jointly managed by the AAPM and the Imaging and Radiation Oncology Core (IROC) Houston Quality Assurance Center (with associated links at ESTRO) to provide open access to test cases as well as step-by-step user guides. While the current report is limited to the two most widely commercially available MBDCAs and only for 192 Ir-based afterloading brachytherapy at this time, this report establishes a general framework that can easily be extended to other brachytherapy MBDCAs and brachytherapy sources. The AAPM, ESTRO, ABG, and ABS recommend that clinical medical physicists implement the workflow presented in this report to validate both the basic and the advanced dose calculation features of their commercial MBDCAs. Recommendations are also given to vendors to integrate advanced analysis tools into their brachytherapy treatment planning system to facilitate extensive dose comparisons. The use of the test cases for research and educational purposes is further encouraged.
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Affiliation(s)
- Luc Beaulieu
- Service de Physique Médicale et Radioprotection et Axe Oncologie du Centre de Recherche du CHU de Québec, CHU de Québec-Université Laval, Québec, Québec, Canada
- Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec, Québec, Canada
| | - Facundo Ballester
- Departamento de Física Atómica, Molecular y Nuclear, IRIMED, IIS-La Fe-Universitat de Valencia, Burjassot, Spain
| | - Domingo Granero
- Departamento de Física Atómica, Molecular y Nuclear, IRIMED, IIS-La Fe-Universitat de Valencia, Burjassot, Spain
| | - Åsa Carlsson Tedgren
- Department of Health, Medicine and Caring Sciences (HMV), Radiation Physics, Linköping University, Linköping, Sweden
- Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, Sweden
- Department of Oncology Pathology, Karolinska Institute, Stockholm, Sweden
| | | | - Jessica R Lowenstein
- Department of Radiation Physics, UT MD Anderson Cancer Center, Houston, Texas, USA
| | - Yunzhi Ma
- Service de Physique Médicale et Radioprotection et Axe Oncologie du Centre de Recherche du CHU de Québec, CHU de Québec-Université Laval, Québec, Québec, Canada
- Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec, Québec, Canada
| | - Firas Mourtada
- Department of Radiation Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Panagiotis Papagiannis
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Mark J Rivard
- Department of Radiation Oncology, Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Frank-André Siebert
- Clinic of Radiotherapy, University Hospital of Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Ron S Sloboda
- Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Ryan L Smith
- Alfred Health Radiation Oncology, The Alfred Hospital, Melbourne, Victoria, Australia
| | - Rowan M Thomson
- Carleton Laboratory for Radiotherapy Physics, Department of Physics, Carleton University, Ottawa, Ontario, Canada
| | - Frank Verhaegen
- Department of Radiation Oncology (MAASTRO), GROW, School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Gabriel Fonseca
- Department of Radiation Oncology (MAASTRO), GROW, School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Javier Vijande
- Departamento de Física Atómica, Molecular y Nuclear, IRIMED, IIS-La Fe-Universitat de Valencia, Burjassot, Spain
- Instituto de Física Corpuscular, IFIC (UV-CSIC), Burjassot, Spain
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Kanda D, Hanada T, Yoshida K, Tanaka T, Eriguchi T, Yorozu A, Ohashi T, Shigematsu N. Evaluation of dose perturbations around iodine-125 seed sources in supplemental external beam prostate radiotherapy. JOURNAL OF RADIATION RESEARCH 2023:7152939. [PMID: 37154504 DOI: 10.1093/jrr/rrad023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 02/07/2023] [Accepted: 03/13/2023] [Indexed: 05/10/2023]
Abstract
We investigated dose perturbations caused by 125I seeds in patients undergoing supplemental external beam radiotherapy (EBRT) for prostate cancer. We examined two types of nonradioactive seed models: model 6711 and model STM1251. All experiments were performed using a water-equivalent phantom. Radiochromic film was used to measure the dose distributions adjacent to the seeds upstream and downstream of the external beam source. Single and clusters of multiple seeds were placed in slots in a solid water (SW) slab to measure dose perturbations with separate versus dense seed placement at beam energies of 6 or 10 MV. Monte Carlo simulations (MCSs) were also performed to include the theoretical basis against film dosimetry. Distinct patterns of dose enhancement (buildup [BU]) were upstream, and dose reduction (builddown [BD]) were downstream of the radiation source. Model 6711 with lower photon beam energies produced larger dose perturbations of BU and BD than the model STM1251. The results showed the same tendency with different seed placements and beam energies. However, these differences were not observed in the rotational irradiation measurement, which replicated a clinical plan. Dose perturbations around seeds result in dose enhancement and dose reduction with varying impact depending on the photon beam energy and seed type. This has the potential to cancel out these perturbations using multiple beam direction fields.
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Affiliation(s)
- Daisuke Kanda
- Department of Radiology, Tokyo Medical Center, National Hospital Organization, Higashigaoka 2-5-1, Meguro-ku, Tokyo 152-8902, Japan
| | - Takashi Hanada
- Department of Radiology, Tokyo Medical Center, National Hospital Organization, Higashigaoka 2-5-1, Meguro-ku, Tokyo 152-8902, Japan
- Department of Radiology, Keio University School of Medicine, Shinanomachi 35, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Kayo Yoshida
- Department of Radiology, Keio University School of Medicine, Shinanomachi 35, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Tomoki Tanaka
- Department of Radiology, Keio University School of Medicine, Shinanomachi 35, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Takahisa Eriguchi
- Radiation Oncology Center, Ofuna Chuo Hospital, Ofuna 6-2-24, Kamakura, Kanagawa 247-0056, Japan
| | - Atsunori Yorozu
- Department of Radiology, Tokyo Medical Center, National Hospital Organization, Higashigaoka 2-5-1, Meguro-ku, Tokyo 152-8902, Japan
| | - Toshio Ohashi
- Department of Radiology, Keio University School of Medicine, Shinanomachi 35, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Naoyuki Shigematsu
- Department of Radiology, Keio University School of Medicine, Shinanomachi 35, Shinjuku-ku, Tokyo 160-8582, Japan
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Safigholi H, Chamberland MJP, Taylor REP, Martinov MP, Rogers DWO, Thomson RM. Update of the CLRP Monte Carlo TG-43 parameter database for high-energy brachytherapy sources. Med Phys 2023; 50:1928-1941. [PMID: 36542404 DOI: 10.1002/mp.16176] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 11/11/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022] Open
Abstract
PURPOSE To update and extend version 2 of the Carleton Laboratory for Radiotherapy Physics (CLRP) TG-43 dosimetry database (CLRP_TG43v2) for high-energy (HE, ≥50 keV) brachytherapy sources (1 169 Yb, 23 192 Ir, 5 137 Cs, and 4 60 Co) using egs_brachy, an open-source EGSnrc application. A comprehensive dataset of TG-43 parameters is compiled, including detailed source descriptions, dose-rate constants, radial dose functions, 1D and 2D anisotropy functions, along-away dose-rate tables, Primary and Scatter Separated (PSS) dose tables, and mean photon energies escaping each source. The database also documents the source models which are freely distributed with egs_brachy. ACQUISITION AND VALIDATION METHODS Datasets are calculated after a recoding of the source geometries using the egs++ geometry package and its egs_brachy extensions. Air kerma per history is calculated in a 10 × 10 × $\,{\times}\, 10\,{\times}\,$ 0.05 cm3 voxel located 100 cm from the source along the transverse axis and then corrected for the lateral and thickness dimensions of the scoring voxel to give the air kerma on the central axis at a point 100 cm from the source's mid-point. Full-scatter water phantoms with varying voxel resolutions in cylindrical coordinates are used for dose calculations. Most data (except for 60 Co) are based on the assumption of charged particle equilibrium and ignore the potentially large effects of electron transport very close to the source and dose from initial beta particles. These effects are evaluated for four representative sources. For validation, data are compared to those from CLRP_TG43v1 and published data. DATA FORMAT AND ACCESS Data are available at https://physics.carleton.ca/clrp/egs_brachy/seed_database_v2 or http://doi.org/10.22215/clrp/tg43v2 including in Excel (.xlsx) spreadsheets, and are presented graphically in comparisons to previously published data for each source. POTENTIAL APPLICATIONS The CLRP_TG43v2 database has applications in research, dosimetry, and brachytherapy planning. This comprehensive update provides the medical physics community with more precise and in some cases more accurate Monte Carlo (MC) TG-43 dose calculation parameters, as well as fully benchmarked and described source models which are distributed with egs_brachy.
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Affiliation(s)
- Habib Safigholi
- Carleton Laboratory for Radiotherapy Physics (CLRP), Department of Physics, Carleton University, Ottawa, Ontario, Canada
| | - Marc J P Chamberland
- Carleton Laboratory for Radiotherapy Physics (CLRP), Department of Physics, Carleton University, Ottawa, Ontario, Canada
| | - Randle E P Taylor
- Carleton Laboratory for Radiotherapy Physics (CLRP), Department of Physics, Carleton University, Ottawa, Ontario, Canada
| | - Martin P Martinov
- Carleton Laboratory for Radiotherapy Physics (CLRP), Department of Physics, Carleton University, Ottawa, Ontario, Canada
| | - D W O Rogers
- Carleton Laboratory for Radiotherapy Physics (CLRP), Department of Physics, Carleton University, Ottawa, Ontario, Canada
| | - Rowan M Thomson
- Carleton Laboratory for Radiotherapy Physics (CLRP), Department of Physics, Carleton University, Ottawa, Ontario, Canada
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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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18
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Ab Shukor NS, Abdullah R, Abdul Aziz MZ, Samson DO, Musarudin M. Dose perturbation effects by metal hip prosthesis in gynaecological 192Ir HDR brachytherapy. Appl Radiat Isot 2023; 196:110751. [PMID: 36871495 DOI: 10.1016/j.apradiso.2023.110751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 02/15/2023] [Accepted: 02/26/2023] [Indexed: 03/02/2023]
Abstract
The present study was conducted to elucidate the effects of hip prostheses in 192Ir HDR brachytherapy and determine dose uncertainties introduced by the treatment planning. A gynaecological phantom irradiated using Nucletron 192Ir microSelectron HDR source was modeled using MCNP5 code. Three hip materials considered in this study were water, bone, and metal prosthesis. According to the obtained results, a dose perturbation was observed within the medium with a higher atomic number, which reduced the dose to the nearby region.
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Affiliation(s)
- N S Ab Shukor
- School of Health Sciences, Universiti Sains Malaysia, Health Campus, 16150, Kubang Kerian, Kelantan, Malaysia
| | - R Abdullah
- Nuclear Medicine, Oncology and Radiotherapy Department, Hospital USM, 16150, Kubang Kerian, Kelantan, Malaysia
| | - M Z Abdul Aziz
- Advance Medical and Dental Institute, Universiti Sains Malaysia, 13200, Bertam, Penang, Malaysia
| | - D O Samson
- Department of Physics, Faculty of Science, University of Abuja, 900211, Abuja, Nigeria
| | - M Musarudin
- School of Health Sciences, Universiti Sains Malaysia, Health Campus, 16150, Kubang Kerian, Kelantan, Malaysia.
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Antunes PCG, Siqueira PDTD, Shorto JBM, Yoriyaz H. A versatile physical phantom design and construction for I-125 dose measurements and dose-to-medium determination. Brachytherapy 2023; 22:80-92. [PMID: 36396567 DOI: 10.1016/j.brachy.2022.10.005] [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: 06/29/2022] [Revised: 09/15/2022] [Accepted: 10/09/2022] [Indexed: 11/16/2022]
Abstract
PURPOSE In this paper we present a phantom designed to provide conditions to generate set of "true" independent reference data as requested by TG-186, and mitigating the scarcity of experimental studies on brachytherapy validation. It was used to perform accurate experimental measurements of dose of 125I brachytherapy seeds using LiF dosimeters, with the objective of experimentally validating Monte Carlo (MC) calculations with model-based dose calculation algorithm (MBDCA). In addition, this work intends to evaluate a methodology to convert the experimental values from LiF into dose in the medium. METHODS AND MATERIALS The proposed PMMA physical phantom features cavities to insert a LiF dosimeter and a 125I seed, adjusted in different configurations with variable thickness. Monte Carlo calculations performed with MCNP6.2 code were used to score the absorbed dose in the LiF and the dose conversion parameters. A sensitivity analysis was done to verify the source of possible uncertainties and quantify their impact on the results. RESULTS The proposed phantom and experimental procedure developed in this work provided precise dose data within 5.68% uncertainty (k = 1). The achieved precision made it possible to convert the LiF responses into absorbed dose to medium and to validate the dose conversion factor methodology. CONCLUSIONS The proposed phantom is simple both in design and as in its composition, thus achieving the demanded precision in dose evaluations due to its easy reproducibility of experimental setup. The results derived from the phantom measurements support the dose conversion methodology. The phantom and the experimental procedure developed here can be applied for other materials and radiation sources.
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Affiliation(s)
| | | | | | - Hélio Yoriyaz
- Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo, Brazil
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20
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Khan AA, Vijay A, Wani SQ, Haq MM. Dosimetric analysis of intracavitary brachytherapy applicators: a practical study. Radiat Oncol J 2022; 40:180-191. [PMID: 36200307 PMCID: PMC9535410 DOI: 10.3857/roj.2022.00199] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 08/29/2022] [Indexed: 11/04/2022] Open
Abstract
Purpose Intracavitary brachytherapy is one of the important methods of gynecological cancer treatment. The effect of attenuation is not considered in the dose calculation method released by the American Association of Physicists in Medicine Task Group No. 43 Report. In this study, the effect of high-dose rate brachytherapy applicators on dose distribution was measured using Gafchromic films and well-type ionization chamber. Materials and Methods A plan created by the treatment planning system was first executed using a well-type ionization chamber with a water equivalent elasto-gel in place for charge collection. Again, same plan was executed using central tandems of various angulations with different diameters of vaginal cylinders and charge collection was measured. For in vitro dose measurements this plan was also executed on tandem and vaginal cylinder assembly with Gafchromic films fixed on the surface of vaginal cylinder. Results The results show that the central tandem when used with different vaginal cylinders resulted in increase in effective attenuation of the beam. The central tandem of 300 angulations when used with a 35-mm diameter vaginal cylinder results in maximum attenuation whereas the 0º tandem when used with 20-mm diameter vaginal cylinder results in least attenuation of the beam. Conclusion Due to the attenuation by various applicators used in brachytherapy for the treatment of gynecological cancers, it can be concluded that the difference between practical dose and the treatment planning system calculated dose should be considered for the correct estimation of the dose to the target and the organs-at-risk.
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Affiliation(s)
- Aijaz A. Khan
- Department of Physics, Institute of Applied Sciences and Humanities, GLA University, Mathura, India
- Department of Radiological Physics and Bio-engineering, Sher-I-Kashmir Institute of Medical Sciences, Jammu and Kashmir, India
- Correspondence: Aijaz A. Khan Department of Radiological Physics and Bio-engineering, Sher-I-Kashmir Institute of Medical Sciences, UT of Jammu and Kashmir, Srinagar 190011, India. Tel: +91-7006764483 Fax: +91-194-2403470 E-mail:
| | - Anuj Vijay
- Department of Physics, Institute of Applied Sciences and Humanities, GLA University, Mathura, India
| | - Shaqul Qamar Wani
- Department of Radiation Oncology, Sher-I-Kashmir Institute of Medical Sciences, Jammu and Kashmir, India
| | - Malik M. Haq
- Department of Radiological Physics and Bio-engineering, Sher-I-Kashmir Institute of Medical Sciences, Jammu and Kashmir, India
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21
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Bittner NHJ, Cox BW, Davis B, King M, Lawton CAF, Merrick GS, Orio P, Ouhib Z, Rossi P, Showalter T, Small W, Schechter NR. ACR-ABS-ASTRO Practice Parameter for Transperineal Permanent Brachytherapy of Prostate Cancer. Am J Clin Oncol 2022; 45:249-257. [PMID: 35588224 DOI: 10.1097/coc.0000000000000915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
AIM/OBJECTIVES/BACKGROUND The American College of Radiology (ACR), American Brachytherapy Society (ABS), and American Society for Radiation Oncology (ASTRO) have jointly developed the following practice parameter for transperineal permanent brachytherapy of prostate cancer. Transperineal permanent brachytherapy of prostate cancer is the interstitial implantation of low-dose rate radioactive seeds into the prostate gland for the purpose of treating localized prostate cancer. METHODS This practice parameter was developed according to the process described under the heading The Process for Developing ACR Practice Parameters and Technical Standards on the ACR website (https://www.acr.org/Clinical-Resources/Practice-Parameters-and-Technical-Standards) by the Committee on Practice Parameters-Radiation Oncology of the Commission on Radiation Oncology, in collaboration with ABS and ASTRO. RESULTS This practice parameter provides a framework for the appropriate use of low-dose rate brachytherapy in the treatment of prostate cancer either as monotherapy or as part of a treatment regimen combined with external-beam radiation therapy. The practice parameter defines the qualifications and responsibilities of all involved radiation oncology personnel, including the radiation oncologist, medical physicist, dosimetrist, radiation therapist, and nursing staff. Patient selection criteria and the utilization of supplemental therapies such as external-beam radiation therapy and androgen deprivation therapy are discussed. The logistics of the implant procedure, postimplant dosimetry assessment, and best practices with regard to safety and quality control are presented. CONCLUSIONS Adherence to established standards can help to ensure that permanent prostate brachytherapy is delivered in a safe and efficacious manner.
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Affiliation(s)
| | | | | | - Martin King
- Brigham and Women's Hospital/Dana-Farber Cancer Institute, Boston, MA
| | | | | | - Peter Orio
- Brigham and Women's Hospital/Dana-Farber Cancer Institute, Boston, MA
| | - Zoubir Ouhib
- Boca Raton Regional Hospital, Lynn Cancer Institute, Boca Raton, FL
| | | | | | - William Small
- Keck Medical Center of USC, Norris Comprehensive Cancer, Center, University of Southern California, Los Angeles, CA
| | - Naomi R Schechter
- Keck Medical Center of USC, Norris Comprehensive Cancer, Center, University of Southern California, Los Angeles, CA
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22
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Ait-Mlouk L, Khalis M, Asnaoui H, Ouabi H, Elboukhari S. Investigation of the dosimetric parameters of 125I BEBIG IsoSeed® I25.S06 source: GATE 8.2 Monte Carlo code. Appl Radiat Isot 2022; 186:110294. [DOI: 10.1016/j.apradiso.2022.110294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 04/17/2022] [Accepted: 05/13/2022] [Indexed: 11/02/2022]
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23
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Karagiannis E, Strouthos I, Leczynski A, Zamboglou N, Ferentinos K. Narrative Review of High-Dose-Rate Interstitial Brachytherapy in Primary or Secondary Liver Tumors. Front Oncol 2022; 12:800920. [PMID: 35299745 PMCID: PMC8920984 DOI: 10.3389/fonc.2022.800920] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 01/31/2022] [Indexed: 12/24/2022] Open
Abstract
The optimal management of intrahepatic malignancies involves a multidisciplinary approach. Although surgical resection has been considered the only curative approach, the use of several minimally invasive ablative techniques has dramatically increased the last two decades, mainly due to the fact that they provide similar oncological results with significantly decreased morbidity. Among these modalities, interstitial liver brachytherapy, probably the most flexible liver ablative method, with excellent clinical data on its safety and effectiveness, is frequently not even mentioned as an option in the current peer reviewed literature and guidelines. Brachytherapy is a type of radiotherapy utilizing radionuclides that are directly inserted into the tumor. Compared to external beam radiation therapy, brachytherapy has the potential to deliver an ablative radiation dose over a short period of time, with the advantage of a rapid dose fall-off, that allows for sparing of adjacent healthy tissue. For numerous malignancies such as skin, gynecological, breast, prostate, head and neck, bladder, liver and soft-tissue tumors, brachytherapy as a monotherapy or combined with external beam radiation therapy, has become a standard treatment for many decades. This review article aims to describe the high-dose-rate liver brachytherapy technique, its selection criteria, present its advantages and disadvantages, as well as the available clinical data, in order to help physicians to explore and hopefully introduce liver brachytherapy into their clinical routine.
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Affiliation(s)
- Efstratios Karagiannis
- Department of Radiation Oncology, German Oncology Center, Limassol, Cyprus.,Department of Medicine, School of Medicine, European University Cyprus, Nicosia, Cyprus
| | - Iosif Strouthos
- Department of Radiation Oncology, German Oncology Center, Limassol, Cyprus.,Department of Medicine, School of Medicine, European University Cyprus, Nicosia, Cyprus
| | - Agnes Leczynski
- Department of Radiation Oncology, German Oncology Center, Limassol, Cyprus
| | - Nikolaos Zamboglou
- Department of Radiation Oncology, German Oncology Center, Limassol, Cyprus.,Department of Medicine, School of Medicine, European University Cyprus, Nicosia, Cyprus
| | - Konstantinos Ferentinos
- Department of Radiation Oncology, German Oncology Center, Limassol, Cyprus.,Department of Medicine, School of Medicine, European University Cyprus, Nicosia, Cyprus
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24
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Villa M, Bert J, Valeri A, Schick U, Visvikis D. Fast Monte Carlo-based Inverse Planning for Prostate Brachytherapy by Using Deep Learning. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2022. [DOI: 10.1109/trpms.2021.3060191] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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25
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Standardization and Validation of Brachytherapy Seeds' Modelling Using GATE and GGEMS Monte Carlo Toolkits. Cancers (Basel) 2021; 13:cancers13215315. [PMID: 34771479 PMCID: PMC8582469 DOI: 10.3390/cancers13215315] [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: 09/02/2021] [Revised: 10/01/2021] [Accepted: 10/19/2021] [Indexed: 11/25/2022] Open
Abstract
Simple Summary This study used GATE and GGEMS simulation toolkits, to estimate dose distribution on Brachytherapy procedures. Specific guidelines were followed as defined by the American Association of Physicists in Medicine (AAPM) as well as by the European SocieTy for Radiotherapy and Oncology (ESTRO). Several types of brachytherapy seeds were modelled and simulated, namely Low-Dose-Rate (LDR), High-Dose-Rate (HDR), and Pulsed-Dose-Rate (PDR). The basic difference between GATE and GGEMS is that GGEMS incorporates GPU capabilities, which makes the use of Monte Carlo (MC) simulations more accessible in clinical routine, by minimizing the computational time to obtain a dose map. During the validation procedure of both codes with protocol data, differences as well as uncertainties were measured within the margins defined by the guidelines. The study concluded that MC simulations may be utilized in clinical practice, to optimize dose distribution in real time, as well as to evaluate therapeutic plans. Abstract This study aims to validate GATE and GGEMS simulation toolkits for brachytherapy applications and to provide accurate models for six commercial brachytherapy seeds, which will be freely available for research purposes. The AAPM TG-43 guidelines were used for the validation of two Low Dose Rate (LDR), three High Dose Rate (HDR), and one Pulsed Dose Rate (PDR) brachytherapy seeds. Each seed was represented as a 3D model and then simulated in GATE to produce one single Phase-Space (PHSP) per seed. To test the validity of the simulations’ outcome, referenced data (provided by the TG-43) was compared with GATE results. Next, validation of the GGEMS toolkit was achieved by comparing its outcome with the GATE MC simulations, incorporating clinical data. The simulation outcomes on the radial dose function (RDF), anisotropy function (AF), and dose rate constant (DRC) for the six commercial seeds were compared with TG-43 values. The statistical uncertainty was limited to 1% for RDF, to 6% (maximum) for AF, and to 2.7% (maximum) for the DRC. GGEMS provided a good agreement with GATE when compared in different situations: (a) Homogeneous water sphere, (b) heterogeneous CT phantom, and (c) a realistic clinical case. In addition, GGEMS has the advantage of very fast simulations. For the clinical case, where TG-186 guidelines were considered, GATE required 1 h for the simulation while GGEMS needed 162 s to reach the same statistical uncertainty. This study produced accurate models and simulations of their emitted spectrum of commonly used commercial brachytherapy seeds which are freely available to the scientific community. Furthermore, GGEMS was validated as an MC GPU based tool for brachytherapy. More research is deemed necessary for the expansion of brachytherapy seed modeling.
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26
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Park H, Paganetti H, Schuemann J, Jia X, Min CH. Monte Carlo methods for device simulations in radiation therapy. Phys Med Biol 2021; 66:10.1088/1361-6560/ac1d1f. [PMID: 34384063 PMCID: PMC8996747 DOI: 10.1088/1361-6560/ac1d1f] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 08/12/2021] [Indexed: 11/12/2022]
Abstract
Monte Carlo (MC) simulations play an important role in radiotherapy, especially as a method to evaluate physical properties that are either impossible or difficult to measure. For example, MC simulations (MCSs) are used to aid in the design of radiotherapy devices or to understand their properties. The aim of this article is to review the MC method for device simulations in radiation therapy. After a brief history of the MC method and popular codes in medical physics, we review applications of the MC method to model treatment heads for neutral and charged particle radiation therapy as well as specific in-room devices for imaging and therapy purposes. We conclude by discussing the impact that MCSs had in this field and the role of MC in future device design.
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Affiliation(s)
- Hyojun Park
- Department of Radiation Convergence Engineering, Yonsei University, Wonju, Republic of Korea
| | - Harald Paganetti
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
| | - Xun Jia
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX 75235, United States of America
| | - Chul Hee Min
- Department of Radiation Convergence Engineering, Yonsei University, Wonju, Republic of Korea
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27
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Liu B, Xiong T, Lu J, Li S, Bai X, Zhou F, Wu Q. Technical note: A fast and accurate analytical dose calculation algorithm for 125 I seed-loaded stent applications. Med Phys 2021; 48:7493-7503. [PMID: 34482556 DOI: 10.1002/mp.15207] [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: 03/11/2021] [Revised: 08/12/2021] [Accepted: 08/28/2021] [Indexed: 12/09/2022] Open
Abstract
PURPOSE The safety and clinical efficacy of 125 I seed-loaded stent for the treatment of portal vein tumor thrombosis (PVTT) have been shown. Accurate and fast dose calculation of the 125 I seeds with the presence of the stent is necessary for the plan optimization and evaluation. However, the dosimetric characteristics of the seed-loaded stents remain unclear and there is no fast dose calculation technique available. This paper aims to explore a fast and accurate analytical dose calculation method based on Monte Carlo (MC) dose calculation, which takes into account the effect of stent and tissue inhomogeneity. METHODS A detailed model of the seed-loaded stent was developed using 3D modeling software and subsequently used in MC simulations to calculate the dose distribution around the stent. The dose perturbation caused by the presence of the stent was analyzed, and dose perturbation kernels (DPKs) were derived and stored for future use. Then, the dose calculation method from AAPM TG-43 was adapted by integrating the DPK and appropriate inhomogeneity correction factors (ICF) to calculate dose distributions analytically. To validate the proposed method, several comparisons were performed with other methods in water phantom and voxelized CT phantoms for three patients. RESULTS The stent has a considerable dosimetric effect reducing the dose up to 47.2% for single-seed stent and 11.9%-16.1% for 16-seed stent. In a water phantom, dose distributions from MC simulations and TG-43-DP-ICF showed a good agreement with the relative error less than 3.3%. In voxelized CT phantoms, taking MC results as the reference, the relative errors of TG-43 method can be up to 33%, while those of TG-43-DP-ICF method were less than 5%. For a dose matrix with 256 × 256 × 46 grid (corresponding to a phantom of 17.2 × 17.2 × 11.5 cm3 ) for 16-seed-loaded stent, it only takes 17 s for TG-43-DP-ICF to compute, compared to 25 h for the full MC calculation. CONCLUSIONS The combination of DPK and inhomogeneity corrections is an effective approach to handle both the presence of stent and tissue heterogeneity. Exhibiting good agreement with MC calculation and computational efficiency, the proposed TG-43-DP-ICF method is adequate for dose evaluation and optimization in seed-loaded stent implantation treatment planning.
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Affiliation(s)
- Bo Liu
- Image Processing Center, Beihang University, Beijing, People's Republic of China.,Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, People's Republic of China
| | - Tianyu Xiong
- Department of Physics, Beihang University, Beijing, People's Republic of China
| | - Jian Lu
- Center of Interventional Radiology & Vascular Surgery, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, China
| | - Shengwei Li
- Center of Interventional Radiology & Vascular Surgery, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, China
| | - Xiangzhi Bai
- Image Processing Center, Beihang University, Beijing, People's Republic of China.,Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, People's Republic of China
| | - Fugen Zhou
- Image Processing Center, Beihang University, Beijing, People's Republic of China.,Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, People's Republic of China
| | - Qiuwen Wu
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, USA
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Mazur TR, Hao Y, Garcia-Ramirez J, Altman MB, Li HH, Thomas MA, Zoberi I, Zoberi JE. Characterization of Dosimetric Differences in Strut-Adjusted Volume Implant Treatment Plans Calculated With TG-43 Formalism and a Model-Based Dose Calculation Algorithm. Int J Radiat Oncol Biol Phys 2021; 110:1200-1209. [PMID: 33662458 DOI: 10.1016/j.ijrobp.2021.02.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 02/08/2021] [Accepted: 02/15/2021] [Indexed: 10/22/2022]
Abstract
PURPOSE To comprehensively characterize dosimetric differences between calculations with a commercial model-based dose calculation algorithm (MBDCA) and the TG-43 formalism in application to accelerated partial breast irradiation (APBI) with the strut-adjusted volume implant (SAVI) applicator. METHODS Dose for 100 patients treated with the SAVI applicator was recalculated with an MBDCA for comparison to dose calculated via TG-43. For every pair of dose calculations, dose-volume histogram (DVH) metrics including V90%, V95%, V100%, V150%, and V200% for the PTV_EVAL were compared. Features were defined for each case including (1) applicator size, (2) ratio between PTV_EVAL contour and 1-cm rind surrounding SAVI applicator, (3) ratio between dwell time in central catheter and total dwell time, and (4) mean computed tomography (CT) number within the lumpectomy cavity. Wilcoxon rank sum tests were performed to test whether treatment plans could be stratified according to feature values into groups with statistically significant dosimetry differences between MBDCA and TG-43. RESULTS For all DVH metrics, differences between TG-43 and MBDCA calculations were statistically significant (P < .05). Minimum (maximum) relative percent differences between the MBDCA and TG-43 for V90%, V95%, and V100% were -2.1% (0.1%), -3.1% (-0.1%), and -5.0% (-0.5%), respectively. The median relative percent difference in mean PTV_EVAL dose between the MBDCA and TG-43 was -3.9%, with minimum (maximum) difference of -6.5% (-1.8%). For V90%, V95%, and V100%, plan quality worsened beyond defined thresholds in 26, 23, and 31 cases with no instances of coverage improvement. Features 1, 2, and 4 were shown to be able to stratify treatment plans into groups with statistically significant differences in dosimetry metrics between MBDCA and TG-43. CONCLUSIONS Investigated dose metrics for SAVI treatments were found to be systematically lower with MBDCA calculation in comparison to TG-43. Plans could be stratified according to several features by the magnitude of dosimetric differences between these calculations.
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Affiliation(s)
- Thomas R Mazur
- Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri.
| | - Yao Hao
- Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri
| | - José Garcia-Ramirez
- Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri
| | - Michael B Altman
- Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri
| | - H Harold Li
- Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri
| | - Maria A Thomas
- Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri
| | - Imran Zoberi
- Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri
| | - Jacqueline E Zoberi
- Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri
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Saminathan S, Maheshraja K, Ganesh KM. Validation of American Association of Physicists in Medicine TG 43 Dosimetry Data in Commercial Treatment Planning System. J Med Phys 2021; 46:197-203. [PMID: 34703104 PMCID: PMC8491312 DOI: 10.4103/jmp.jmp_20_21] [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: 01/27/2021] [Revised: 06/22/2021] [Accepted: 06/29/2021] [Indexed: 11/18/2022] Open
Abstract
AIMS This study aimed to validate the dosimetric data of low-energy photon-emitting low-dose rate (LE-LDR) brachytherapy seed sources in commercial treatment planning system (TPS). MATERIALS AND METHODS The LE-LDR seed sources dosimetric data were published in the American Association of Physicists in Medicine (AAPM) Task Group reports TG-43 (1995), TG-43U1 (2004), TG-43U1S1 (2007), and TG-43U1S2. The Bhabha Atomic Research centre (BARC) 125I Ocu-Prosta seed dosimetry data are also available in the literature. The commercially available TPSs are using both two-dimensional (cylindrically symmetric line-source) and one-dimensional (1D) (point source) dose-calculation formalisms. TPS used in this study uses only 1D dose-calculation formalism for permanent implant dosimetry. The point-dose calculation, dose summation, isodose representation, and dose-volume histogram quality assurance tests were performed in this study. The point-source dose-calculation tests were performed for all the available sources in the literature. The others tests were performed for the I-125 BARC Ocu-Prosta seeds. The TPS-calculated doses were validated using manual calculation. RESULTS AND DISCUSSION In point-source calculation test, the TPS-calculated point-dose values are within ±2% agreement with manually calculated dose for all the seeds studied. The agreement between the TPS and manually calculated dose is 0.5% for the dose summation test. The isodose line pass through the grid points at an equal distance was verified visually on the computer screen for seed used clinically. In dose-volume histogram test, the TPS-determined volume was compared with the real volume. CONCLUSION Misinterpretation of the TPS test and/or misunderstanding of the TG-43 dose-calculation formalism may cause large errors. It is very important to validate the TPS using literature provided dosimetric data. The dosimetric data of BARC 125I Ocu-Prosta Seed are validated with other AAPM TG-43-recommended seeds. The dose calculation of Best® NOMOS permanent implant TPS is accurate for all permanent implant seeds studied.
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Affiliation(s)
- Sathiyan Saminathan
- Department of Radiation Physics, Kidwai Memorial Institute of Oncology, Bengaluru, Karnataka, India
| | - K. Maheshraja
- Department of Radiation Physics, Kidwai Memorial Institute of Oncology, Bengaluru, Karnataka, India
| | - K. M. Ganesh
- Department of Radiation Physics, Kidwai Memorial Institute of Oncology, Bengaluru, Karnataka, India
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30
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Yousif YAM, Osman AFI, Halato MA. A review of dosimetric impact of implementation of model-based dose calculation algorithms (MBDCAs) for HDR brachytherapy. Phys Eng Sci Med 2021; 44:871-886. [PMID: 34142317 DOI: 10.1007/s13246-021-01029-8] [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: 11/26/2020] [Accepted: 06/14/2021] [Indexed: 11/29/2022]
Abstract
To obtain dose distributions more physically representative to the patient anatomy in brachytherapy, calculation algorithms that can account for heterogeneity are required. The current standard AAPM Task Group No 43 (TG-43) dose calculation formalism has some clinically relevant dosimetric limitations. Lack of tissue heterogeneity and scattered dose corrections are the major weaknesses of the TG-43 formalism and could lead to systematic dose errors in target volumes and organs at risk. Over the last decade, model-based dose calculation algorithms (MBDCAs) have been clinically offered as complementary algorithms beyond the TG43 formalism for high dose rate (HDR) brachytherapy treatment planning. These algorithms provide enhanced dose calculation accuracy by using the information in the patient's computed tomography images, which allows modeling the patient's geometry, material compositions, and the treatment applicator. Several researchers have investigated the implementation of MBDCAs in HDR brachytherapy for dose optimization, but moving toward using them as primary algorithms for dose calculations is still lagging. Therefore, an overview of up-to-date research is needed to familiarize clinicians with the current status of the MBDCAs for different cancers in HDR brachytherapy. In this paper, we review the MBDCAs for HDR brachytherapy from a dosimetric perspective. Treatment sites covered include breast, gynecological, lung, head and neck, esophagus, liver, prostate, and skin cancers. Moreover, we discuss the current status of implementation of MBDCAs and the challenges.
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Affiliation(s)
- Yousif A M Yousif
- Department of Radiation Oncology, North West Cancer Centre-Tamworth Hospital, Tamworth, Australia.
| | - Alexander F I Osman
- Department of Medical Physics, Al-Neelain University, 11121, Khartoum, Sudan.
| | - Mohammed A Halato
- Department of Medical Physics, Al-Neelain University, 11121, Khartoum, Sudan
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31
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Dickhoff LR, Vrancken Peeters MJ, Bosman PA, Alderliesten T. Therapeutic applications of radioactive sources: from image-guided brachytherapy to radio-guided surgical resection. THE QUARTERLY JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING : OFFICIAL PUBLICATION OF THE ITALIAN ASSOCIATION OF NUCLEAR MEDICINE (AIMN) [AND] THE INTERNATIONAL ASSOCIATION OF RADIOPHARMACOLOGY (IAR), [AND] SECTION OF THE SOCIETY OF... 2021; 65:190-201. [PMID: 34105339 DOI: 10.23736/s1824-4785.21.03370-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
It is well known nowadays that radioactivity can destroy the living cells it interacts with. It is therefore unsurprising that radioactive sources, such as iodine-125, were historically developed for treatment purposes within radiation oncology with the goal of damaging malignant cells. However, since then, new techniques have been invented that make creative use of the same radioactivity properties of these sources for medical applications. Here, we review two distinct kinds of therapeutic uses of radioactive sources with applications to prostate, cervical, and breast cancer: brachytherapy and radioactive seed localization. In brachytherapy (BT), the radioactive sources are used for internal radiation treatment. Current approaches make use of real-time image guidance, for instance by means of magnetic resonance imaging, ultrasound, computed tomography, and sometimes positron emission tomography, depending on clinical availability and cancer type. Such image-guided BT for prostate and cervical cancer presents a promising alternative and/or addition to external beam radiation treatments or surgical resections. Radioactive sources can also be used for radio-guided tumor localization during surgery, for which the example of iodine-125 seed use in breast cancer is given. Radioactive seed localization (RSL) is increasingly popular as an alternative tumor localization technique during breast cancer surgery. Advantages of applying RSL include added flexibility in the clinical scheduling logistics, an increase in tumor localization accuracy, and higher patient satisfaction; safety measures do however have to be employed. We exemplify the implementation of RSL in a clinic through experiences at the Netherlands Cancer Institute.
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Affiliation(s)
- Leah R Dickhoff
- Department of Radiation Oncology, Leiden University Medical Center, Leiden, The Netherlands -
| | - Marie-Jeanne Vrancken Peeters
- Department of Surgical Oncology, Netherlands Cancer Institute - Antoni van Leeuwenhoek, Amsterdam, The Netherlands.,Department of Surgery, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Peter A Bosman
- Life Sciences and Health group, Centrum Wiskunde & Informatica, Amsterdam, The Netherlands
| | - Tanja Alderliesten
- Department of Radiation Oncology, Leiden University Medical Center, Leiden, The Netherlands
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Wu J, Xie Y, Ding Z, Li F, Wang L. Monte Carlo study of TG-43 dosimetry parameters of GammaMed Plus high dose rate 192 Ir brachytherapy source using TOPAS. J Appl Clin Med Phys 2021; 22:146-153. [PMID: 33955134 PMCID: PMC8200518 DOI: 10.1002/acm2.13252] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/06/2021] [Accepted: 03/28/2021] [Indexed: 12/29/2022] Open
Abstract
PURPOSE To develop a simulation model for GammaMed Plus high dose rate 192 Ir brachytherapy source in TOPAS Monte Carlo software and validate it by calculating the TG-43 dosimetry parameters and comparing them with published data. METHODS We built a model for GammaMed Plus high dose rate brachytherapy source in TOPAS. The TG-43 dosimetry parameters including air-kerma strength SK , dose-rate constant Λ, radial dose function gL (r), and 2D anisotropy function F(r,θ) were calculated using Monte Carlo simulation with Geant4 physics models and NNDC 192 Ir spectrum. Calculations using an old 192 Ir spectrum were also carried out to evaluate the impact of incident spectrum and cross sections. The results were compared with published data. RESULTS For calculations using the NNDC spectrum, the air-kerma strength per unit source activity SK /A and Λ were 1.0139 × 10-7 U/Bq and 1.1101 cGy.h-1 .U-1 , which were 3.56% higher and 0.62% lower than the reference values, respectively. The gL (r) agreed with reference values within 1% for radial distances from 2 mm to 20 cm. For radial distances of 1, 3, 5, and 10 cm, the agreements between F(r,θ) from this work and the reference data were within 1.5% for 15° < θ < 165°, and within 4% for all θ values. The discrepancies were attributed to the updated source spectrum and cross sections. They caused deviations of the SK /A of 2.90% and 0.64%, respectively. As for gL (r), they caused average deviations of -0.22% and 0.48%, respectively. Their impact on F(r,θ) was not quantified for the relatively high statistical uncertainties, but basically they did not result in significant discrepancies. CONCLUSION A model for GammaMed Plus high dose rate 192 Ir brachytherapy source was developed in TOPAS and validated following TG-43 protocols, which can be used for future studies. The impact of updated incident spectrum and cross sections on the dosimetry parameters was quantified.
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Affiliation(s)
- Jianan Wu
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.,Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shenzhen, 518116, China
| | - Yaoqin Xie
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Zhen Ding
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shenzhen, 518116, China
| | - Feipeng Li
- Shenzhen Key Laboratory of Advanced Machine Learning and Application, College of Mathematics and Statistics, Shenzhen University, Shenzhen, 518060, China
| | - Luhua Wang
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shenzhen, 518116, China.,Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China
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Feasibility Study of Robust Optimization to Reduce Dose Delivery Uncertainty by Potential Applicator Displacements for a Cervix Brachytherapy. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11062592] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Brachytherapy is an important technique to increase the overall survival of cervical cancer patients. However, a possible shift of the applicators in relation to the target and organs at risk may occur between imaging and treatment. Without daily adaptive brachytherapy planning, these applicator displacements can lead to a significant change in dose distribution. In order to resolve it, a robust optimization method had been developed using a genetic algorithm combined with a median absolute deviation as a robustness evaluation function. The resulting robustness plans from our strategy might be worth considering according to the GEC-ESTRO guidelines. From the point of view of dose delivery uncertainty from applicator displacement, the robust optimization may be considered with caution in a single-plan approach for High Dose Rate brachytherapy treatment planning and should be confirmed by a more thorough investigation.
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Wilby S, Palmer A, Polak W, Bucchi A. A review of brachytherapy physical phantoms developed over the last 20 years: clinical purpose and future requirements. J Contemp Brachytherapy 2021; 13:101-115. [PMID: 34025743 PMCID: PMC8117707 DOI: 10.5114/jcb.2021.103593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 11/13/2020] [Indexed: 12/04/2022] Open
Abstract
Within the brachytherapy community, many phantoms are constructed in-house, and less commercial development is observed as compared to the field of external beam. Computational or virtual phantom design has seen considerable growth; however, physical phantoms are beneficial for brachytherapy, in which quality is dependent on physical processes, such as accuracy of source placement. Focusing on the design of physical phantoms, this review paper presents a summary of brachytherapy specific phantoms in published journal articles over the last twenty years (January 1, 2000 - December 31, 2019). The papers were analyzed and tabulated by their primary clinical purpose, which was deduced from their associated publications. A substantial body of work has been published on phantom designs from the brachytherapy community, but a standardized method of reporting technical aspects of the phantoms is lacking. In-house phantom development demonstrates an increasing interest in magnetic resonance (MR) tissue mimicking materials, which is not yet reflected in commercial phantoms available for brachytherapy. The evaluation of phantom design provides insight into the way, in which brachytherapy practice has changed over time, and demonstrates the customised and broad nature of treatments offered.
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Affiliation(s)
- Sarah Wilby
- Department of Radiotherapy Physics, Clinical Hematology, and Oncology Centre, Portsmouth Hospitals NHS Trust, Cosham, Portsmouth, United Kingdom
- Department of Mechanical Engineering, Faculty of Technology University of Portsmouth, Portsmouth, United Kingdom
| | - Antony Palmer
- Department of Radiotherapy Physics, Clinical Hematology, and Oncology Centre, Portsmouth Hospitals NHS Trust, Cosham, Portsmouth, United Kingdom
- Department of Mechanical Engineering, Faculty of Technology University of Portsmouth, Portsmouth, United Kingdom
| | - Wojciech Polak
- Department of Radiotherapy Physics, Clinical Hematology, and Oncology Centre, Portsmouth Hospitals NHS Trust, Cosham, Portsmouth, United Kingdom
- Department of Mechanical Engineering, Faculty of Technology University of Portsmouth, Portsmouth, United Kingdom
| | - Andrea Bucchi
- Department of Mechanical Engineering, Faculty of Technology University of Portsmouth, Portsmouth, United Kingdom
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Guebert A, Roumeliotis M, Watt E, Meyer T, Quirk S. Dosimetric consequences of seed placement accuracy in permanent breast seed implant brachytherapy. Brachytherapy 2021; 20:664-672. [PMID: 33358141 DOI: 10.1016/j.brachy.2020.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 11/18/2020] [Accepted: 11/24/2020] [Indexed: 10/22/2022]
Abstract
PURPOSE This study quantifies the dosimetric impact of implant accuracy and derives a quantitative relationship relating implant accuracy to target dosimetry. METHODS AND MATERIALS A framework was developed to simulate multiple implants for error combinations. Spherical clinical target volumes (CTVs) were modeled with volumes 1.4 cm3, 9.2 cm3, and 20.6 cm3, representing the range seen clinically. Each CTV was expanded 10 mm isotropically to create a planning target volume (PTV).. Random and systematic seed placement errors were simulated by shifting needles from their planned positions. Implant errors were simulated over the range of clinically practical errors in permanent breast seed implant. The relative effect on target coverage was evaluated. Regression analysis was performed to derive relationships between CTV dosimetry and the magnitude of implant accuracy. The validity of the clinically used 10 mm PTV margin for each of the CTVs was assessed. RESULTS Introducing practical implant errors resulted in CTV V90% median (10th and 90th percentile) of 97.7% (85.9% and 100%), 96.2% (86.8% and 99.7%), and 100% (77.8% and 100%) for the typical, large, and small CTV, respectively. All CTVs show similar trends in target coverage. Polynomials were derived relating seed placement accuracy to median (R2 = 0.82) and 10th percentile (R2 = 0.78) CTV V90%.. CONCLUSIONS: This work quantitatively describes the relationship between implant accuracy and CTV coverage. Based on simulations, the 10 mm PTV margin is adequate to maintain target coverage. These equations can be used with institutional seed placement accuracy to estimate coverage.
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Affiliation(s)
- Alexandra Guebert
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada; Division of Medical Physics, Tom Baker Cancer Centre, Calgary, AB, Canada.
| | - Michael Roumeliotis
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada; Division of Medical Physics, Tom Baker Cancer Centre, Calgary, AB, Canada; Department of Oncology, University of Calgary, Calgary, AB, Canada; Okolo Health, Calgary, AB, Canada
| | - Elizabeth Watt
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada; Division of Medical Physics, Tom Baker Cancer Centre, Calgary, AB, Canada; Okolo Health, Calgary, AB, Canada
| | - Tyler Meyer
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada; Division of Medical Physics, Tom Baker Cancer Centre, Calgary, AB, Canada; Department of Oncology, University of Calgary, Calgary, AB, Canada; Okolo Health, Calgary, AB, Canada
| | - Sarah Quirk
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada; Division of Medical Physics, Tom Baker Cancer Centre, Calgary, AB, Canada; Department of Oncology, University of Calgary, Calgary, AB, Canada
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First brachytherapy treatment of prostate cancer in Nigeria using low dose rate radioactive iodine 125. AFRICAN JOURNAL OF UROLOGY 2020. [DOI: 10.1186/s12301-020-00098-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
We report the first prostate brachytherapy in Nigeria, using low dose radioactive iodine 125 (I-125) permanent seeds implant.
Case Presentation
The low dose rate brachytherapy using I-125 implants was performed in a private clinic in the city of Benin, Edo state of Nigeria. This pilot study reports the case of the first two patients with prostate cancer. The patients were treated under spinal anesthesia using 2 ml of heavy bupibacaine which is equivalent to 10 mg of bupibacaine. Biopsy, total blood count, electrolytes, urea, creatinine, urinalysis, electrocardiogram, chest X-ray, prostate-specific antigen and bone scan were checked prior to the procedure. The first two prostate cancer patients who were in low risk category successfully received the treatment in the first day of the clinic’s operations. This paper describes the settings in which these clinical operations occurred, detailing the type of technology used, the clinical procedure and the obtained dose distribution.
Conclusions
The paper ends with discussing the overall cost of the investment and the challenges encountered as well as the perspectives of extending the brachytherapy practice to treat other cancer diseases, such as breast and genealogical cancers.
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End-to-end dosimetric audit: A novel procedure developed for Irish HDR brachytherapy centres. Phys Med 2020; 80:221-229. [PMID: 33190078 DOI: 10.1016/j.ejmp.2020.10.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 09/28/2020] [Accepted: 10/05/2020] [Indexed: 11/24/2022] Open
Abstract
PURPOSE A dosimetric audit of Ir-192 high dose rate (HDR) brachytherapy remote after-loading units was carried out in 2019. All six brachytherapy departments on the island of Ireland participated in an end-to-end test and in a review of local HDR dosimetry procedures. MATERIALS AND METHODS A 3D-printed customised phantom was created to position the following detectors at known distances from the HDR source: a Farmer ionization chamber, GafChromic film and thermoluminescent dosimeters (TLDs). Dedicated HDR applicator needles were used to position an Ir-192 source at 2 cm distance from these detectors. The end-to-end dosimetry audit pathway was performed at each host site and included the stages of imaging, applicator reconstruction, treatment planning and delivery. Deviations between planned and measured dose distributions were quantified using gamma analysis methods. Local procedures were also discussed between auditors and hosts. RESULTS The mean difference between Reference Air Kerma Rate (RAKR) measured during the audit and RAKR specified by the vendor source certificate was 1.3%. The results of end-to-end tests showed a mean difference between calculated and measured dose of 2.5% with TLDs and less than 0.5% with Farmer chamber measurements. GafChromic films showed a mean gamma passing rates of >95% for plastic and metal applicators with 2%/1 mm global tolerance criteria. CONCLUSIONS The results of this audit indicate dosimetric consistency between centres. The 'end to end' dosimetry audit methodology for HDR brachytherapy has been successfully implemented in a multicentre environment, which included different models of Ir-192 sources and different treatment planning systems. The ability to create a 3D-printed water-equivalent phantom customised to accurately position all three detector types simultaneously at controlled distances from the Ir-192 source under evaluation gives good reproducibility for end-to-end methodology.
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Torres Díaz J, Grad GB, Venencia CD, Bonzi EV. A novel and fast methodology to calculate doses in LDR brachytherapy. Appl Radiat Isot 2020; 166:109394. [PMID: 33091859 DOI: 10.1016/j.apradiso.2020.109394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 07/19/2020] [Accepted: 08/18/2020] [Indexed: 10/23/2022]
Abstract
We present the concept of a new methodology for faster simulation of the doses in brachytherapy with permanent implants, based on the knowledge of the seeds arrangement, adding previously simulated doses in an equivalent medium in terms of the atomic composition of the organ in question. To perform the doses calculations we use Monte Carlo simulations. We simulated a cylindrical I-125 seed and compared our results against published data. Our proposal is to have the doses simulated previously in different arrangement of seed-absorbents, and then, considering the spacial positions of the seeds after the implants, these doses can be directly added, obtaining a very fast computation of the total dose. Two phantoms of prostates with permanent implant seeds in 2D and 3D arrangements were simulated. The results of the proposed methodology were compared with two complete Monte Carlo simulations in 2D and 3D designs. Differences in doses were analysed, obtaining statistical discrepancies of less than 1% and reducing the simulation time by more than 4 orders of magnitude. With the proposed methodology, it is possible to perform rapid dose calculations in brachytherapy, using laptop or desktop computers.
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Affiliation(s)
- Jorge Torres Díaz
- CONICET, Córdoba, Argentina; FaMAF, Universidad Nacional de Córdoba, Córdoba, Argentina
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Evaluation of a collapsed-cone convolution algorithm for esophagus and surface mold 192Ir brachytherapy treatment planning. Brachytherapy 2020; 20:393-400. [PMID: 33071170 DOI: 10.1016/j.brachy.2020.09.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 09/08/2020] [Accepted: 09/10/2020] [Indexed: 11/20/2022]
Abstract
PURPOSE TG43 does not account for a lack of scatter and tissue and applicator heterogeneities. The advanced collapsed-cone engine (ACE) algorithm available for use in the Oncentra Brachy treatment planning system (Elekta AB, Stockholm, Sweden) can model these conditions more accurately and is evaluated for esophageal and surface mold brachytherapy treatments. METHODS AND MATERIALS ACE was commissioned for use then compared against TG43 for five esophageal and five surface mold treatment plans. Dosimetric differences between each algorithm were assessed using superimposed comparisons and dose-volume histogram statistics. RESULTS Esophagus (6 Gy per fraction): Compared with TG43, ACE demonstrated up to a 0.63% and 0.05 Gy reduction in planning target volume (PTV) V100% and PTV D98, respectively. Lung D2cc and bone D2cc deviated by up to 0.09 Gy and 0.03 Gy, respectively. Lung D0.1 cc and bone D0.1 cc both deviated by up to 0.12 Gy. Surface mold (4.5 Gy per fraction): Compared with TG43, ACE demonstrated up to a 12.5% and 0.18 Gy reduction in PTV V80% and PTV D98, respectively. Bone D2cc and D0.1 cc both reduced by up to 0.2 Gy when modeled with ACE. Increasing mold size laterally increased the dosimetric differences between TG43 and ACE. CONCLUSIONS TG43 generally overestimated dose delivered to the target volume and organs at risk for the sites investigated. Dosimetric differences observed for esophageal treatments were minimal; however, surface mold treatments would benefit from the increased dosimetric accuracy offered by ACE. Implementation should be considered for surface mold 192Ir treatment planning, but increased calculation time, additional contouring, and mass density assignment requirements should be scrutinized with regard to their potentially negative impact on current clinical practice.
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Fulkerson RK, Perez‐Calatayud J, Ballester F, Buzurovic I, Kim Y, Niatsetski Y, Ouhib Z, Pai S, Rivard MJ, Rong Y, Siebert F, Thomadsen BR, Weigand F. Surface brachytherapy: Joint report of the AAPM and the GEC‐ESTRO Task Group No. 253. Med Phys 2020; 47:e951-e987. [DOI: 10.1002/mp.14436] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 07/15/2020] [Accepted: 07/16/2020] [Indexed: 02/06/2023] Open
Affiliation(s)
- Regina K. Fulkerson
- Department of Medical Physics University of Wisconsin–Madison Madison WI53705 USA
| | - Jose Perez‐Calatayud
- Radiotherapy Department La Fe Hospital Valencia46026 Spain
- Radiotherapy Department Clinica Benidorm Alicante03501 Spain
| | - Facundo Ballester
- Department of Atomic, Molecular and Nuclear Physics University of Valencia Burjassot46100 Spain
| | - Ivan Buzurovic
- Dana‐Farber/Brigham and Women’s Cancer Center Harvard Medical School Boston MA02115 USA
| | - Yongbok Kim
- Department of Radiation Oncology University of Arizona Tucson AZ85724 USA
| | - Yury Niatsetski
- R&D Elekta Brachytherapy Waardgelder 1 Veenendaal3903 DD Netherlands
| | - Zoubir Ouhib
- Radiation Oncology Department Lynn Regional Cancer CenterBoca Raton Community Hospital Boca Raton FL33486 USA
| | - Sujatha Pai
- Radion Inc. 20380 Town Center Lane, Suite 135 Cupertino CA95014 USA
| | - Mark J. Rivard
- Department of Radiation Oncology Alpert Medical School Brown University Providence RI02903 USA
| | - Yi Rong
- Department of Radiation Oncology University of California Davis Comprehensive Cancer Center Sacramento CA95817 USA
| | - Frank‐André Siebert
- UK S‐HCampus Kiel, Klinik fur Strahlentherapie (Radioonkologie) Arnold‐Heller‐Str. 3Haus 50 KielD‐24105 Germany
| | - Bruce R. Thomadsen
- Department of Medical Physics University of Wisconsin–Madison Madison WI53705 USA
| | - Frank Weigand
- Carl Zeiss Meditec AG Rudolf‐Eber‐Straße 11 Oberkochen73447 Germany
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Safigholi H, Chamberland MJP, Taylor REP, Allen CH, Martinov MP, Rogers DWO, Thomson RM. Update of the CLRP TG‐43 parameter database for low‐energy brachytherapy sources. Med Phys 2020; 47:4656-4669. [DOI: 10.1002/mp.14249] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/08/2020] [Accepted: 05/05/2020] [Indexed: 12/23/2022] Open
Affiliation(s)
- Habib Safigholi
- Carleton Laboratory for Radiotherapy Physics (CLRP) Department of Physics Carleton University Ottawa ON K1S 5B6 Canada
| | - Marc J. P. Chamberland
- Carleton Laboratory for Radiotherapy Physics (CLRP) Department of Physics Carleton University Ottawa ON K1S 5B6 Canada
| | - Randle E. P. Taylor
- Carleton Laboratory for Radiotherapy Physics (CLRP) Department of Physics Carleton University Ottawa ON K1S 5B6 Canada
| | - Christian H. Allen
- Carleton Laboratory for Radiotherapy Physics (CLRP) Department of Physics Carleton University Ottawa ON K1S 5B6 Canada
| | - Martin P. Martinov
- Carleton Laboratory for Radiotherapy Physics (CLRP) Department of Physics Carleton University Ottawa ON K1S 5B6 Canada
| | - D. W. O. Rogers
- Carleton Laboratory for Radiotherapy Physics (CLRP) Department of Physics Carleton University Ottawa ON K1S 5B6 Canada
| | - Rowan M. Thomson
- Carleton Laboratory for Radiotherapy Physics (CLRP) Department of Physics Carleton University Ottawa ON K1S 5B6 Canada
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Guthier CV, Devlin PM, Harris TC, O'Farrell DA, Cormack RA, Buzurovic I. Development and clinical implementation of semi-automated treatment planning including 3D printable applicator holders in complex skin brachytherapy. Med Phys 2020; 47:869-879. [PMID: 31855280 DOI: 10.1002/mp.13975] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 12/04/2019] [Accepted: 12/09/2019] [Indexed: 11/09/2022] Open
Abstract
PURPOSE High-dose-rate brachytherapy (HDR-BT) is a treatment option for malignant skin diseases compared to external beam radiation therapy, HDR-BT provides improved target coverage, better organ sparing, and has comparable treatment times. This is especially true for large clinical targets with complex topologies. To standardize and improve the quality and efficacy of the treatments, a novel streamlined treatment approach in complex skin HDR-BT was developed and implemented. This approach consists of auto generated treatment plans and a 3D printable applicator holder (3D-AH). MATERIALS AND METHODS The in-house developed planning system automatically segments computed tomography simulation images (a), optimizes a treatment plan (b), and generates a model of the 3D-AH (c). The 3D-AH is used as an immobilization device for the flexible Freiburg flap applicator used to deliver treatment. The developed, automated planning is compared against the standard clinical plan generation process for a flat 10 × 10 cm2 field, curved fields with radii of 4, 6, and 8 cm, and a representative clinical case. The quality of the 3D print is verified via an additional CT of the flap applicator latched into the holder, followed by an automated rigid registration with the original planning CT. Finally, the methodology is implemented and tested clinically under an IRB approval. RESULTS All automatically generated plans were reviewed and accepted for clinical use. For the clinical workflow, the coverage achieved at a prescription depth for the flat 4, 6, and 8 cm applicator was (100.0 ± 4.9)%, (100.0 ± 4.9)%, (96.0 ± 0.3)%, and (98.4 ± 0.3)%, respectively. For auto planning, the coverage was (99.9 ± 0.3)%, (100.0 ± 0.2)%, (100.0 ± 0.3)%, and (100.1 ± 0.2)%. For the clinical test case, the D90 for the clinical workflow and auto planning was found to be 93.5% and 100.29% of the prescribed dose, respectively. Processing of the patient's CT to generate trajectories and positions as well as the 3D model of the applicator took <5 min. CONCLUSION This workflow automates time intensive catheter digitizing and treatment planning. Compared to printing full applicators, the use of 3D-AH reduces the complexity of the 3D prints, the amount of the material to be used, the time of 3D printing, and amount of quality assurance required. The proposed methodology improves the overall treatment plan quality in complex HDR-BT and impact patient treatment outcomes potentially.
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Affiliation(s)
- Christian V Guthier
- Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, 02215, USA
| | - Phillip M Devlin
- Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, 02215, USA
| | - Thomas C Harris
- Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, 02215, USA
| | - Desmond A O'Farrell
- Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, 02215, USA
| | - Robert A Cormack
- Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, 02215, USA
| | - Ivan Buzurovic
- Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, 02215, USA
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Luong NH, Alderliesten T, Pieters BR, Bel A, Niatsetski Y, Bosman PA. Fast and insightful bi-objective optimization for prostate cancer treatment planning with high-dose-rate brachytherapy. Appl Soft Comput 2019. [DOI: 10.1016/j.asoc.2019.105681] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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44
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A M, M G. Determination of TG-43 Dosimetric Parameters for Photon Emitting Brachytherapy Sources. J Biomed Phys Eng 2019; 9:425-436. [PMID: 31531295 PMCID: PMC6709347 DOI: 10.31661/jbpe.v0i0.570] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 06/13/2016] [Indexed: 11/25/2022]
Abstract
Objective: Brachytherapy sources are widely used for the treatment of cancer. The report of Task Group No. 43 (TG-43) of American Association of Physicists in Medicine
is known as the most common method for the determination of dosimetric parameters for brachytherapy sources. The aim of this study is to obtain TG-43 dosimetric
parameters for 60Co, 137Cs, 192Ir and 103Pd brachytherapy sources by Monte Carlo simulation.
Methods: In this study, 60Co (model Co0.A86), 137Cs (model 6520-67), 192Ir (model BEBIG) and 103Pd (model OptiSeed) brachytherapy sources were simulated using MCNPX Monte Carlo code.
To simulate the sources, the exact geometric characterization of each source was defined in Monte Carlo input programs. Dosimetric parameters including air kerma strength,
dose rate constant, radial dose function and anisotropy function were calculated for each source. Each input program was run with sufficient number of particle histories.
The maximum type A statistical uncertainty in the simulation of the 60Co, 137Cs, 192Ir and 103Pd sources, were equal to 4%, 4%, 3.19% and 6.50%, respectively.
Results: The results for dosimetry parameters of dose rate constant, radial dose function and anisotropy function for the 60Co, 137Cs, 192Ir and 103Pd sources
in this study demonstrated good agreement with other studies.
Conclusion: Based on the good agreement between the results of this study and other studies, the TG-43 results for Co0.A86 60Co, 67-65200 137Cs, BEBIG 192Ir and OptiSeed 103Pd sources
are validated and can be used as input data in treatment planning systems (TPSs) and to validate the TPS calculations.
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Affiliation(s)
- Mozaffari A
- Medical Physics Department, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ghorbani M
- Medical Physics Department, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
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Evaluation of BrachyDose Monte Carlo code for HDR brachytherapy: dose comparison against Acuros®BV and TG-43 algorithms. JOURNAL OF RADIOTHERAPY IN PRACTICE 2019. [DOI: 10.1017/s1460396919000220] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractAim:The aim of this study is to investigate the accuracy of dose distributions calculated by the BrachyDose Monte Carlo (MC) code in heterogeneous media for high-dose-rate (HDR) brachytherapy and to evaluate its usability in the clinical brachytherapy treatment planning systems.Materials and methods:For dose comparisons, three different dose calculation algorithms were used in this study. Namely, BrachyDose MC code, Eclipse TG-43 dose calculation tool and Acuros®BV model-based dose calculation algorithm (MBDCA). Dose distributions were obtained using any of the above codes in various scenarios including ‘homogenous water medium scenario’, an ‘extreme case heterogeneous media scenario’ and clinically important ‘a patient with a cervical cancer scenario’. In the ‘extreme case, heterogeneous media scenario’, geometry is a rare combination of unusual high-density and low-density materials and it is chosen to provide a test environment for the propagation of photons in the interface of two materials with different absorption and scattering properties. GammaMed 192Ir Model 12i Source is used as the HDR brachytherapy source in this study. Dose calculations were performed for the cases where there is either a single source or five sources planted into the phantom geometry in all homogenous water phantom and extreme case heterogeneous media scenarios. For the scenario a patient with a cervical cancer, dose calculations were performed in a voxelized rectilinear phantom, which is constructed from a series of computed tomography (CT) slices of a patient, which are obtained from a CT device.Results:In homogeneous water phantom scenario, we observed no statistically significant dose differences among the dose distributions calculated by any of the three algorithms at almost every point in the geometry. In the extreme case heterogeneous media scenario, the dose calculation engines Acuros®BV and BrachyDose are agreed well within statistics in every region of the geometry and even in the points close to the interfaces of low-density and high-density materials. On the other hand, the dose values calculated by these two codes are significantly different from those calculated by the TG-43 algorithm. In the ‘a patient with a cervical cancer scenario’, the calculated D2cc dose difference between Acuros®BV and BrachyDose codes is within 2% in the rectum and 11% for the bladder and sigmoid. There was no meaningful difference in the mean dose values between MBDCAs in the bone structures.Conclusions:In this study, the accurate dose calculation capabilities of the BrachyDose program in HDR brachytherapy were investigated on various scenarios and, as a MC dose calculation tool, its effectiveness in HDR brachytherapy was demonstrated by comparative dose analysis.
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Reed AJ, Kim JH, Burrage JW. Development and application of a simple method for calculating breast dose from radio-guided occult lesion localisation using iodine-125 seeds (ROLLIS). ACTA ACUST UNITED AC 2019; 64:075020. [DOI: 10.1088/1361-6560/ab0149] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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A Monte Carlo investigation of the dose distribution for new I-125 Low Dose Rate brachytherapy source in water and in different media. POLISH JOURNAL OF MEDICAL PHYSICS AND ENGINEERING 2019. [DOI: 10.2478/pjmpe-2019-0003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Permanent and temporary implantation of I-125 brachytherapy sources has become an official method for the treatment of different cancers. In this technique, it is essential to determine dose distribution around the brachytherapy source to choose the optimal treatment plan. In this study, the dosimetric parameters for a new interstitial brachytherapy source I-125 (IrSeed-125) were calculated with GATE/GEANT4 Monte Carlo code. Dose rate constant, radial dose function and 2D anisotropy function were calculated inside a water phantom (based on the recommendations of TG-43U1 protocol), and inside several tissue phantoms around the IrSeed-125 capsule. Acquired results were compared with MCNP simulation and experimental data. The dose rate constant of IrSeed-125 in the water phantom was about 1.038 cGy·h−1U−1 that shows good consistency with the experimental data. The radial dose function at 0.5, 0.9, 1.8, 3 and 7 cm radial distances were obtained as 1.095, 1.019, 0.826, 0.605, and 0.188, respectively. The results of the IrSeed-125 is not only in good agreement with those calculated by other simulation with MCNP code but also are closer to the experimental results. Discrepancies in the estimation of dose around IrSeed-125 capsule in the muscle and fat tissue phantoms are greater than the breast and lung phantoms in comparison with the water phantom. Results show that GATE/GEANT4 Monte Carlo code produces accurate results for dosimetric parameters of the IrSeed-125 LDR brachytherapy source with choosing the appropriate physics list. There are some differences in the dose calculation in the tissue phantoms in comparison with water phantom, especially in long distances from the source center, which may cause errors in the estimation of dose around brachytherapy sources that are not taken account by the TG43-U1 formalism.
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Babadagli ME, Sloboda R, Doucette J. A mixed-integer linear programming optimization model framework for capturing expert planning style in low dose rate prostate brachytherapy. ACTA ACUST UNITED AC 2019; 64:075007. [DOI: 10.1088/1361-6560/ab075c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Perez-Calatayud J, Ballester F, Carlsson Tedgren Å, Rijnders A, Rivard MJ, Andrássy M, Niatsetski Y, Schneider T, Siebert FA. GEC-ESTRO ACROP recommendations on calibration and traceability of LE-LDR photon-emitting brachytherapy sources at the hospital level. Radiother Oncol 2019; 135:120-129. [PMID: 31015157 DOI: 10.1016/j.radonc.2019.02.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 02/09/2019] [Indexed: 11/25/2022]
Abstract
Prostate brachytherapy treatment using permanent implantation of low-energy (LE) low-dose rate (LDR) sources is successfully and widely applied in Europe. In addition, seeds are used in other tumour sites, such as ophthalmic tumours, implanted temporarily. The calibration issues for LE-LDR photon emitting sources are specific and different from other sources used in brachytherapy. In this report, the BRAPHYQS (BRAchytherapy PHYsics Quality assurance System) working group of GEC-ESTRO, has developed the present recommendations to assure harmonized and high-quality seed calibration in European clinics. There are practical aspects for which a clarification/procedure is needed, including aspects not specifically accounted for in currently existing AAPM and ESTRO societal recommendations. The aim of this report has been to provide a European wide standard in LE-LDR source calibration at end-user level, in order to keep brachytherapy treatments with high safety and quality levels. The recommendations herein reflect the guidance to the ESTRO brachytherapy users and describe the procedures in a clinic or hospital to ensure the correct calibration of LE-LDR seeds.
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Affiliation(s)
- Jose Perez-Calatayud
- Radiotherapy Department, University and Polytechnic La Fe Hospital, Valencia, Spain; IRIMED Joint Research Unit (IIS La Fe - UV), Valencia, Spain.
| | - Facundo Ballester
- IRIMED Joint Research Unit (IIS La Fe - UV), Valencia, Spain; Departmento of Atomic, Molecular and Nuclear Physics, University of Valencia, Valencia, Spain
| | - Åsa Carlsson Tedgren
- Radiation Physics, Department of Medicine and Health (IMH), Linköping University, Linköping, Sweden; Section of Radiotherapy Physics and Engineering, Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, Sweden; Department of Oncology Pathology, Karolinska Institute, Stockholm, Sweden
| | - Alex Rijnders
- Department of Radiotherapy, Europe Hospitals, Brussels, Belgium
| | - Mark J Rivard
- Department of Radiation Oncology, Alpert Medical School of Brown University, Providence, USA
| | | | - Yury Niatsetski
- R&D Elekta Brachytherapy Waardgelder 1, Veenendaal, Netherlands
| | - Thorsten Schneider
- Physikalisch-Technische Bundesanstalt (PTB), Department of Radiation Protection Dosimetry, Braunschweig, Germany
| | - Frank-André Siebert
- UK S-H, Campus Kiel, Klinik für Strahlentherapie (Radioonkologie), Kiel, Germany
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Hansen JB, Culberson WS, DeWerd LA. A convex windowless extrapolation chamber to measure surface dose rate from 106 Ru/ 106 Rh episcleral plaques. Med Phys 2019; 46:2430-2443. [PMID: 30873611 DOI: 10.1002/mp.13488] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/19/2019] [Accepted: 02/28/2019] [Indexed: 11/08/2022] Open
Abstract
PURPOSE A convex windowless extrapolation chamber was developed as a primary measurement device to determine surface dose rate from curved 106 Ru/106 Rh episcleral plaques. METHODS A convex extrapolation chamber without an entrance window was constructed for this work, and surface dose rate measurements were performed with two curved CCB-type 106 Ru/106 Rh plaques (S/N 2545 and 2596) manufactured by Eckert & Ziegler BEBIG. FARO ® Gage measurements were performed to verify the radius of curvature for the convex electrode and the concave plaque surface. Furthermore, the collecting electrode area was verified through capacitance measurements. Chamber correction factors for divergence and backscatter were generated using the EGSnrc cavity user code. For each source, surface dose rate was measured with the convex extrapolation chamber and compared with on-contact measurements made with curved un-laminated EBT3 film strips. A Monte Carlo correction was generated for radiochromic film measurements to account for volume averaging within the active layer and effects of phantom scatter. Additionally, extrapolation chamber results for each plaque were compared with scintillation detector measurements performed by the manufacturer. For the second source (S/N 2596), a comparison was also made with the Monte Carlo-corrected surface dose rate measured at the National Physical Laboratory (NPL) using cylindrical alanine pellets. Finally, source measurements were performed using conventional ionization chambers (Exradin A26, A1SL, and A20) within a custom fixture to investigate the transfer of extrapolation chamber surface dose rate to clinics. RESULTS For the first 106 Ru/106 Rh plaque (S/N 2545), average surface dose rate from the convex windowless extrapolation chamber was found to be 1.5% higher than the corresponding value from curved un-laminated EBT3 film measurements and 5.6% lower than the manufacturer value. For the second source (S/N 2596), the extrapolation chamber surface dose rate was 2.5% higher than the un-laminated EBT3 film result, 4.5% lower than the manufacturer value, and 3.9% higher compared to corrected alanine measurements made at NPL. Total uncertainty in the extrapolation chamber measurement was estimated to be approximately ± 7.0% (k = 2). For the plaque measurements made using conventional ionization chambers with a custom fixture, surface dose rate from the transfer technique was found to agree within 3.8% with the expected convex extrapolation chamber result for S/N 2596. CONCLUSIONS A convex windowless extrapolation chamber was developed as a primary measurement device for 106 Ru/106 Rh plaques. Through comparison with the extrapolation chamber, the accuracy of surface dose rate measurements from current dosimetry techniques was assessed and agreement was seen within 5.6%. Finally, it was found that conventional ionization chambers could be calibrated with a reference 106 Ru/106 Rh plaque in order to transfer the extrapolation chamber result for surface dose rate to clinics.
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Affiliation(s)
- Jon B Hansen
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Wesley S Culberson
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Larry A DeWerd
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
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