核素153Sm体素S因子特性的研究

基于体素S因子计算个体化病例的三维剂量是目前核医学研究的一个重要方向.153Sm是目前骨转移治疗常用的核素之一.本文利用EGS4蒙特卡罗程序包构建了基于体素的三维吸收剂量分布模拟程序,计算了不同情况下153Sm的S因子,探讨了介质成分和物理密度对S因子的影响.结果表明:1)不同物理密度对S因子有明显影响;2)在相同物理密度的情况下,不同介质对S因子的影响相对较小.计算结果为基于体素S因子计算核素治疗的三维剂量提供了参考,明确了在不考虑介质和物理密度差异时S因子的误差.

Characteristics of the voxel S values of nuclide 153Sm

The calculation of three dimensional dose distributions of radionuclide therapy based on the voxel S values is very important in the nuclear medicine domain, ^153Sm is one of the nuclides often used for bone metastasis therapy. The S values of ^153Sm in different conditions were calculated based on the program of 3D voxel dose calculation built on the Monte Carlo package EGS4. The influences of both material composition and density on the S value were discussed. It is shown that there are obvious influences of material densities on the S value, and while the density is the same, there are fewer influences of material composition on the S value. The calculation could give some help to the 3D voxel dose calculations for radionuclide therapy, The work also indicated the ranges of error of the S values while disregarding the influence of material density and compositions.