放射性^(125)I粒子平面布源剂量学的分布研究

A dosimetric research on radioactive ^(125)I seed plane implantation

目的:探讨9颗2.22×107Bq125I粒子单平面不同插值模式的剂量学分布差异。方法:利用计算机三维治疗计划系统(3D-TPS)创建9颗2.22×107Bq(0.6 MCI)125I粒子10种分布模式,分别计算出60Gy、80Gy、130Gy、145Gy和200Gy等剂量分布曲线及曲线包含的面积、长径、短径。结果:粒子分布模式不同时相同等剂量曲线包含的面积、长径、短径存在差显著异;60Gy、80Gy、130Gy、145Gy和200Gy等剂量曲线内面积最大的粒子排列依次为:X1.5Y1.5、X1Y1(2)1.5、X0.5Y1、X0.5Y1、X0.5Y0.5(2)1。相对应的面积为:1272.31mm2、969.69mm2、571.94 mm2、536.64mm2、444.09mm2。结论:9颗2.22×107Bq125I粒子单平面不同插值模式显著影响周边剂量及治疗效果。

Objective：To study the dosimetric effect of different^125 II seeds arrangements when implanted at the same number and activity in a plan. Methods：Established 10 different arrangements of ^125 Iseed plane implantation using the three -dimensional treatment planning system （3D - TPS）and created the isodose curves of 60Gy, 80Gy, 130Gy, 145Gy and 200Gy. The area, radius in the 60Gy,8OGy, 130Gy, 145Gy and 200Gy isodose curves were calcu- lated with the professional image analysis software. Results：The area,radius in the same isodose curves were not simi- lar when the arrangement was different. The arrangements which have the maximum area in the 60Gy,80Gy,130Gy, 145Gy and 200Gy isodose curves are X1.5Y1.5, X1 Y1 （2） 1.5, X0.5Y1, X0.5Y1, X0.5Y0.5 （2） 1 and the area were 1272.31 mm^2 ,969.69 mm^2, 571.94 mm^2, 536.64 mm^2 ,444.09 mm^2. Conclusion：The MPD and therapeutic effect are influenced significantly by the arrangement of the seeds even the number and activity are equal.