Pinnacle与Eclipse计划系统对感兴趣区体积计算的比较

摘要

目的 分析Pinnacle与Eclipse计划系统在计算靶区与正常器官感兴趣区(ROI)体积上的差异,为临床应用提供参考.方法 在Pinnacle计划系统上、在层厚分别为1、3、5mm的CT上分别勾画1、2、5个层面的正方形和圆形ROI.同时选取头、胸、腹部肿瘤病例各5例.在患者CT上勾画常见的正常器官ROI.将图像和ROI通过DICOM协议传输至Pinnacle和Eclipse计划系统,分析两种计划系统计算的ROI体积.结果 小体积的ROI两种计划系统计算结果有明显的差异,ROI体积越小体积差异越大(小体积相差12倍,大体积基本相同);体积计算的差异受许多因素的影响,感兴趣区的层数和几何体的大小与体积计算的差异显著线性相关(R2=1.000,P=0.000),CT层厚(R2=0.200,P=0.972)和几何体形状(R2=0.200,P=0.089)的对体积计算的差异的影响不显著.几何中心不一致对Pinnacle的ROI体积计算无影响,Eclipse的ROI体积计算有3%左右的增加.CT层厚与R0I体积呈正比(Pinnacle的R2=0.548,P=0.011;Eclipse的R2=0.502,P=0.027).对视交叉、视神经和晶体的体积差异均＞35%.结论 两种计划系统间传输ROI,特别是小体积ROI,需要注意两种计划系统在计算ROI体积时的差异.%Objective To compare the difference region of interest volume (ROI) calculation method between Pinnacle and Eclipse treatment planning system. Methods To acquire CT image with 3 of slice thickness (1 mm, 3 mm, and 5 mm). Delineate 1, 2 and 5 slices square and circle contours in Pinnacle treatment planning system. Meanwhile 15 cases that include 5 cases with head neck tumor, 5 with thorax tumor and 5 with abdomen tumor were selected. Those image and ROI were transfer to Eclipse treatment plan system by DICOM RT protocol . The ROI volume was compared between two TPS . Results For ROI with small volume, the volume difference between TPS was obvious (for small volume ROI have 12 times difference, for big volume ROI almost same). The volume difference between TPS was influenced by many factors. The number of ROI slice and the magnitude of ROI was related with the difference between TPS (R2 = 1. 000, P = 0. 000). The CT thickness (R2 = 0. 200, P = 0. 972 ) and the shape of ROI ( R2 =0. 200, P = 0. 089) were not significant factors. The center of ROI on different axis was not affect the volume calculation in Pinnacle, which cause 3% different in Eclipse. The CT thickness was proportional to the ROI volume ( Pinnacle R2 = 0. 548, P = 0. 011; Eclipse R2 = 0. 502, P = 0. 027 ). In clinical case, optic chiasm and Len averagely have more than 35% volume difference between those two TPS. Conclusions We should pay more attention about the difference volume calculation algorithm between Pinnacle and Eclipse,especially when transfer small volume ROI to another TPS, which may have significant difference.