Krim Deae-Eddine, Bakari Dikra, Zerfaoui Mustapha, Rrhioua Abdeslem, Oulhouq Yassine
Faculte des Sciences, Universite Mohammed Premier Oujda, Oujda, Morocco.
National School of Applied Sciences, University Mohamed 1st, Oujda, Morocco.
Rep Pract Oncol Radiother. 2021 Dec 30;26(6):928-938. doi: 10.5603/RPOR.a2021.0111. eCollection 2021.
This work aims to provide a simulated method to be used by designers of medical accelerators and in clinical centers to manage and minimize particles' interaction in the patient-dependent part of a 6 MV X-Ray Beam generated by the Elekta linear accelerator system, based on the latest GATE software version 9.0 Monte Carlo simulation, IAEA phase space data, and the last version of "Slurm" computing cluster.
The experimental results are obtained using the Elekta 6 MV accelerator. The simulation MC developed includes the majority of the patient-dependent segments, such as Multi-Leaf Collimator (MLC), Tongue and Groove T&G, Rounded leaf Part, including the Jaws (XY). This model is used, with a simulated Iba Blue Phantom 2 homogeneous water phantom with dimensions 480 × 480 × 410 mm, positioned at a Source-to-Surface-Distance (SSD) of 100 cm, all of the interactions of the mega voltage 6 MV radiations in water are simulated. The IAEA phase space (PS) provided by the International Atomic Energy Agency database and cluster computing (Slurm HPC-MARWAN, CNRST, Morocco) are employed to reduce our simulation time.
The results confirm that there are many interactions in all areas and the patient-dependent part's internal structures. Thus, electrons and positrons participation appear in the generated field previously designed to be an X-ray beam. Besides, to validate our implementation geometry, the PDD's and transverse profiles, at a depth ranging from 1.5 to 20 cm, for a field size of 10 × 10 cm, the beam quality such as , (cm), (cm), , the two relative differences in dose were derived on and are calculated, respectively. Additionally, gamma index formalism for 2%/2 mm criteria is used. Once and for all, we typically take a good agreement between simulation MC GATE 9.0 and the experiment data with an error less than 2%/2 mm.
In the field of X-ray photons, a significant contribution of electrons and positrons has been found. This contribution could be enough to be essential or affect the delivered dose. A good agreement of 98% between this new approach of simulation MC GATE 9.0 software based on IAEA phase space and experimental dose distributions is observed regarding the validation tests used in this task.
本研究旨在提供一种模拟方法，供医用加速器设计人员和临床中心使用，以便基于最新的GATE软件版本9.0蒙特卡罗模拟、国际原子能机构（IAEA）相空间数据以及最新版本的“Slurm”计算集群，来管理和最小化医科达直线加速器系统产生的6兆伏X射线束中与患者相关部分的粒子相互作用。
实验结果通过医科达6兆伏加速器获得。所开发的模拟蒙特卡罗模型包括了大部分与患者相关的部分，如多叶准直器（MLC）、舌槽（T&G）、圆形叶片部分，包括 jaws（XY）。该模型用于模拟尺寸为480×480×410毫米的Iba Blue Phantom 2均匀水体模，放置在源皮距（SSD）为100厘米处，模拟了兆伏级6兆伏辐射在水中的所有相互作用。利用国际原子能机构数据库提供的IAEA相空间（PS）和集群计算（摩洛哥国家科学技术研究中心的Slurm HPC - MARWAN）来减少我们的模拟时间。
结果证实，在所有区域以及与患者相关部分的内部结构中都存在许多相互作用。因此，电子和正电子参与了先前设计为X射线束的生成场。此外，为了验证我们的实施几何结构，对于10×10厘米的射野尺寸，在1.5至20厘米的深度范围内，得出了百分深度剂量（PDD）和横向剖面，如射野半值层（ ）、等效方野（ ）（厘米）、射野输出剂量率（ ）、剂量率稳定性（ ），分别计算了在 和 处的两个剂量相对差异。此外，使用了2%/2毫米标准的伽马指数形式。最终，我们发现模拟蒙特卡罗GATE 9.0与实验数据之间通常具有良好的一致性，误差小于2%/2毫米。
在X射线光子领域，已发现电子和正电子有显著贡献。这种贡献可能足以至关重要或影响所输送的剂量。关于本任务中使用的验证测试，基于IAEA相空间的模拟蒙特卡罗GATE 9.0软件的这种新方法与实验剂量分布之间观察到98%的良好一致性。
