基于体素模型的光子外照射大鼠器官剂量模拟计算

获得外照射条件下的大鼠器官剂量,对于放射医学剂量-效应关系研究具有重要意义。本文基于大鼠微型CT图像建立大鼠体素模型,并研究光子外照射情况下大鼠器官剂量。大鼠体素模型质量323.7 g,单个体素尺寸为0.16 mm×0.16 mm×2 mm,包含大鼠大部分关键器官和组织。利用蒙特卡罗模拟程序MCNP计算获得了4种照射几何条件、21个单能(10 keV～10 MeV)平行光子束外照射情况下的器官剂量转换系数,最后对器官剂量随光子能量的变化进行了分析与讨论。

Rat organ dose calculation for external photon irradiation basedon voxel model based on voxel model

To obtain the organ dose of externally exposed rat for studying dose-effect relationship in radiation medicine,a voxel model based on Micro-CT images of a SD rat was developed to calculate rat organ dose for external photon irradiation.The rat voxel model had a size of 0.16 mm×0.16 mm×2 mm,weighed about 323 g and contained most of the key organs or tissues.Monte Carlo simulation was carried out to obtain organ dose conversion coefficients for 21 external monoenergetic parallel photon beams between 10 keV and 10 MeV under four different irradiation geometry conditions.The organ dose with varying photon energy was also discussed and analyzed.