Physics Department, College of Science, Jouf University, Sakaka, Saudi Arabia.
Physics Department, Faculty of Science, Assiut University, Assiut, Egypt.
J Appl Clin Med Phys. 2020 Mar;21(3):134-141. doi: 10.1002/acm2.12836. Epub 2020 Feb 18.
This study is to validate the utilization of Monte Carlo (MC) simulation to model the head of Primus linear accelerator, thereafter, using it to estimate the energy fluence distribution (EFD), the percentage depth dose (PDD), and beam profiles.
The BEAM code that is based on the EGS code has been used for modeling the linear accelerator head for 10 MeV electron beam with different applicator sizes (10 × 10, 15 × 15, and 20 × 20 cm ). The phase space was acquired from BEAM at the end of each applicator and then used as an input file to DOSXYZ and BEAMDP to calculate the EFD, PDD, and beam profiles.
There were a good consistency between the outcomes of the MC simulation and measured PDD and off-axis dose profiles that performed in a water phantom for all applicators. The PDD for the applicators proved to be favorable as a direct comparison of R , R , R , and R yielded results of < 2 mm, while it was 6 mm in R for the applicator 15 × 15 cm . The discrepancies in the surface doses (<3%) showed a quick decline in the build-up region and differences reached 0% within the first 2.4 mm. For the beam profiles comparison, the differences ranged from 2% (2 mm) to 3% (6 mm) for all applicators.
Our examination demonstrated that the MC simulation by BEAM code was accurate in modeling the Primus linear accelerator head.
本研究旨在验证使用蒙特卡罗（MC）模拟来对 Primus 直线加速器机头进行建模，进而利用其来估算能量注量分布（EFD）、百分深度剂量（PDD）和射束轮廓。
采用基于 EGS 代码的 BEAM 代码，对不同施源器尺寸（10×10、15×15 和 20×20 cm）下 10 MeV 电子束的直线加速器机头进行建模。在每个施源器的末端，从 BEAM 中获取相空间，并将其用作 DOSXYZ 和 BEAMDP 计算 EFD、PDD 和射束轮廓的输入文件。
对于所有施源器，MC 模拟的结果与在水模体中进行的 PDD 和离轴剂量分布的实测结果之间存在良好的一致性。施源器的 PDD 表现良好，直接比较 R 、 R 、 R 、和 R 的结果均<2 mm，而对于 15×15 cm 的施源器，R 的值为 6 mm。在表面剂量（<3%）方面的差异表明，在建成区迅速下降，差异在最初的 2.4 mm 内达到 0%。对于射束轮廓的比较，所有施源器的差异范围在 2%（2 mm）到 3%（6 mm）之间。
我们的检查表明，BEAM 代码的 MC 模拟在对 Primus 直线加速器机头进行建模方面是准确的。
