Joya Musa, Nedaie Hassan Ali, Geraily Ghazale, Ghorbani Mahdi, Sheikhzadeh Peyman, Arani Mahmud Naraqi
Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Radiology Department, Kabul University of Medical Sciences, Kabul, Afghanistan.
Heliyon. 2022 Mar 27;8(3):e09168. doi: 10.1016/j.heliyon.2022.e09168. eCollection 2022 Mar.
This study aims to validate the dosimetric characteristics of High Dose Rate (HDR) Co source (Co0.A86 model) using GATE Geant4-based Monte Carlo code. According to the recommendation of the American Association of Physicists in Medicine (AAPM) task group report number 43, the dosimetric parameters of a new brachytherapy source should be verified either experimentally or by Monte Carlo calculation before clinical applications. The validated Co source in this study will be used for the simulation of intensity-modulated brachytherapy (IMBT) of vaginal cancer using the same GATE Geant4-based Monte Carlo code in the future.
GATE (version 9.0) simulation code was used to model and calculate the required TG-43U1 dosimetric data of the Co HDR source. DoseActors were defined for calculation of dose rate constant, radial dose function, and anisotropy function in a water phantom with an 80 cm radius.
The dose rate constant was obtained as which shows a relative difference of 2.01% compared to the consensus value, 1.092 . The calculated results of anisotropy and radial dose functions starting from 0.1 cm to 10 cm around the source showed excellent agreement with the results of published studies. The mean variation of the radial dose and anisotropy functions values from the consensus data were 1% and 0.9% respectively.
Findings from this investigation revealed that the validation of the HDR Co source is feasible by the GATE Geant4-based Monte Carlo code. As a result, the GATE Monte Carlo code can be used for the verification of the brachytherapy treatment planning system.
本研究旨在使用基于GATE Geant4的蒙特卡罗代码验证高剂量率（HDR）钴源（Co0.A86型号）的剂量学特性。根据美国医学物理学家协会（AAPM）任务组第43号报告的建议，在临床应用之前，应通过实验或蒙特卡罗计算来验证新的近距离放射治疗源的剂量学参数。本研究中经验证的钴源未来将用于使用相同的基于GATE Geant4的蒙特卡罗代码模拟阴道癌的调强近距离放射治疗（IMBT）。
使用GATE（9.0版）模拟代码对钴HDR源所需的TG-43U1剂量学数据进行建模和计算。定义剂量作用体以计算半径为80 cm的水体模中的剂量率常数、径向剂量函数和各向异性函数。
获得的剂量率常数为 ，与共识值1.092 相比，相对差异为2.01%。从源周围0.1 cm到10 cm的各向异性和径向剂量函数的计算结果与已发表研究的结果显示出极好的一致性。径向剂量和各向异性函数值与共识数据的平均差异分别为1%和0.9%。
本研究结果表明，基于GATE Geant4的蒙特卡罗代码对HDR钴源进行验证是可行的。因此，GATE蒙特卡罗代码可用于验证近距离放射治疗治疗计划系统。
