ABSTRACT

This study investigates the effects of nanoparticles entity shapes inside tumor mass on dose distribution and dose enhancement. Gold (${\hspace{0.17em}}_{\hspace{0.17em}}^{197}Au$) and Platinum (${\hspace{0.17em}}_{\hspace{0.17em}}^{195}Pt$) nanoparticles of four different shapes were used in this study. Each one has different air cavity inside, which in turns affect the scattering probability. However, all of them are spheres and have the same diameter of 1 μm, these shapes are solid sphere (SS), hexagonal air cavities sphere (HS), triangular air cavities sphere (TS), and circular air cavities sphere (CS). In this study, a Monte Carlo GATE 8.2 code was used to simulate a 6 MV photon beam for Elekta Infinity Versa HD. A voxel of 1 mm, which contains 17 same nanoparticles stacked together, is irradiated with 6 MV beam. Dose distribution at all adjacent voxel are measured using a ‘DOSE ACTOR’ tool available in GATE 8.2 simulation code. Results showed that the most enhanced dose distribution found is in (HS), as it produces more scattering radiation, hence increasing the dose to tumor cells inside the cavities. This investigation could give indication about scattering behavior toward nanoscale particles. In addition, it may, improve radiation planning for patients being treated with radiotherapy.

摘要

这项研究调查了肿瘤块内部纳米粒子实体形状对剂量分布和剂量增强的影响。金子 （${\hspace{0.17em}}_{\hspace{0.17em}}^{197}\mathrm{一种}ü$）和白金（${\hspace{0.17em}}_{\hspace{0.17em}}^{195}PŤ$研究中使用了四种不同形状的纳米粒子。每个人内部都有不同的空气腔，这反过来会影响散射概率。但是，它们都是球形，并且具有相同的直径1μm，这些形状是实心球（SS），六边形气孔球（HS），三角形气孔球（TS）和圆形气孔球（CS）。在这项研究中，蒙特卡洛GATE 8.2代码用于模拟Elekta Infinity Versa HD的6 MV光子束。用6 MV光束照射1mm的体素，其中包含17个相同的纳米粒子堆叠在一起。使用GATE 8.2仿真代码中提供的“ DOSE ACTOR”工具测量所有相邻体素的剂量分布。结果表明，发现最大的剂量分布是在（HS）中，因为它会产生更多的散射辐射，因此增加了腔内肿瘤细胞的剂量。这项研究可以为纳米级粒子的散射行为提供指示。另外，它可以改善接受放射治疗的患者的放射计划。