两种放疗计划系统对仿真体模和患者及均匀体模进行剂量计算结果比较

Two radiotherapy treatment planning systems in comparison of dose calculating results for simulation phantom, patients and homogeneous organization phantom

目的通过Eclipse与Pinnacle^3 V 7．4f两种TPS对仿真体模、患者及均匀组织体模的CT图像进行剂量计算，比较两种TPS进行非均匀组织计算的结果差异，并与均匀体模的结果进行比较。方法对患者、仿真体模以及均匀体模的CT图像利用两种TPS作相同计划，比较临床常用指标（肺V20和V30、计划靶区的D95以及等中心点和等中心层面内8个兴趣点的剂量）的结果差异。结果对患者及仿真体模而言，虽然两TPS对等中心点剂量计算的结果差异较小，但其他指标却存在较大差异（利用二级准直器照射时患者计划靶区D95的差异最大可达10．17％，仿真体模为4．64％；利用多叶光栅照射时患者计划靶区D95的差异最大达10．74％，仿真体模为5．66％；对于计划靶区边缘1～4点的剂量差异，患者有超过10．00％的情况，仿真体模最大为7．65％；肺V30的差异也较大）。而对均匀体模而言，两TPS对各指标的计算差异却较小。结论两TPS对仿真体模计算的结果差异比患者小，而对患者及仿真体模计算的结果差异要大于对均匀组织体模的。

Objective Using Eclipse and Pinnacles V 7.4f treatment planning sytems （TPS） for dose calculation of the CT images of simulation phantom, patients and homogeneous organization phantom, to compare the differences between the two TPS for the calculation of non-uniform organizations. Methods For the CT images of simulation phantom, patients and homogeneous organization phantom, the calculating results between the two TPS were compared,including the common used clinical indexes of V20 and V30 of the lung,D95 of the planning target volume,the doses of the ISO and eight points of interest inside ISO slice. Results For simulation phantom and patients, although the calculating differences of the isoeenter doses between the two TPS were small, the differences of other indicators were large. For example, when using secondary collimator irradiation,the maximal D95 difference of planning target volume reached 10.17% for patients and 4.64% for simulation phantom, When using multileaf collimator irradiation, the maximal D95 difference reached 10.74% for patients and 5.66% for simulation phantom, Sometimes the dose differences of points 1-4 at the edge of planning target volume were more than 10%. In addition,the V30 differences of the lung were large too. But for the homogeneous organization phantom, the calculating differences were small. Conclusions The calculating differences between the two TPS are less for simulation phantom than for patients ,and more for simulation phantom and patients than for homogeneous organization phantom.