Poorbaygi Hosein, Sardari Elham, Aghamiri Seyed Mahmoud Reza, Sheibani Shahab, Arjmand Mojtaba, Moradi Somayeh, Ghassemi Fariba
Radiation Application Research School Nuclear Science and Technology Tehran Iran.
Department of Radiation Medicine Shahid Beheshti University Tehran Iran.
Precis Radiat Oncol. 2024 Jun 16;8(2):70-76. doi: 10.1002/pro6.1231. eCollection 2024 Jun.
Eye plaque radiation therapy is the treatment of choice for small- and medium-sized choroidal melanomas. This study investigated the dose distribution around eye plaques containing I seeds to treat ocular melanoma using Monte Carlo N-Particle eXtended (MCNPX) and Plaque Simulator (PS) software.
Dosimetry evaluation and comparison of the resulting isodose curves for I COMS plaques were performed using the MCNPX code. The isodose curves and dose distributions were calculated using PS treatment planning for a I COMS plaque.
In the validation, the maximum relative difference between the results of this study and those reported in other literature was approximately 9%-10% for the COMS plaques. The dose distributions of MCNPX were lower than those of PS with a relative difference of approximately 27.7%-35.4%. The dose distribution may differ depending on the I source spectra and seed design used in the two methods. In addition, the dose algorithm used in PS made a major contribution to the relative differences between the results.
The PS did not provide accurate details of dose distribution near the surface of the plaque insert. The source parameters used in each program should be studied more carefully to determine the source of the differences in the estimated dose values.
眼敷贴放射治疗是中小型脉络膜黑色素瘤的首选治疗方法。本研究使用蒙特卡罗N粒子扩展程序（MCNPX）和敷贴模拟器（PS）软件，研究含碘籽源的眼敷贴周围的剂量分布，以治疗眼部黑色素瘤。
使用MCNPX代码对碘125眼敷贴剂量学进行评估，并比较所得等剂量曲线。使用PS治疗计划对碘125眼敷贴计算等剂量曲线和剂量分布。
在验证过程中，本研究结果与其他文献报道结果之间的最大相对差异，对于眼敷贴而言约为9%-10%。MCNPX的剂量分布低于PS，相对差异约为27.7%-35.4%。剂量分布可能因两种方法中使用的碘源光谱和籽源设计而异。此外，PS中使用的剂量算法对结果之间的相对差异起了主要作用。
PS未提供敷贴插入物表面附近剂量分布的准确细节。应更仔细地研究每个程序中使用的源参数，以确定估计剂量值差异的来源。
