基于Auto-Planning的宫颈癌调强放疗的剂量学研究

Dosimetric Study of Auto-Planning Based on Cervical Cancer Intensity-Modulated Radiotherapy

目的研究基于Auto-Planning(AP)的宫颈癌计划靶区和危及器官的剂量学差异,并与当前宫颈癌调强放疗(Intensity-Modulated Radiation Therapy,IMRT)计划相比较。方法选取10例I~Ⅲ期宫颈癌病例,用Pinnacle3 V9.10计划系统基于同一CT图像进行IMRT和AP计划设计,比较两种不同计划的剂量体积直方图,分析靶区适形度指数、均匀性指数和危及器官受照剂量的差异。结果 AP计划与IMRT计划相比,靶区Dmax降低,差异有统计学意义,P=0.001。靶区Dmin、Dmean、CI和HI差异均无统计学意义。膀胱V50,直肠的V45、V50、Dmean,左右股骨头V30、Dmean,AP计划明显优于IMRT计划,差异有统计学意义(P<0.05)。膀胱V30、V40、V45,直肠V40及左右股骨头V40受照剂量均低于IMRT计划。结论宫颈癌AP计划能够达到与IMRT计划相似的靶区剂量分布。同时,宫颈癌AP计划能降低靶区最高剂量,减少热点,降低危及器官受照剂量。

Objective The purpose of this article was to study the dosimetry difference between the Auto-planning （AP） and conventional intensity-modulated radiotherapy （IMRT） in cervical cancer patients. Methods Ten grade I～Ⅲ cervical cancer patients were selected to perform the analysis. AP plan and IMRT plan were obtained by the Pinnacle3 V9.10 treatment planning system. The dose-volume histogram, homogeneity index, conformity index, and the doses that received by the organs at risk （OARs） were compared. Results Compared with the IMRT, the AP could generate treatment plan with lower target region Dmax, and the statistical difference of AP was signifcant （P=0.001）. But no statistical difference was found in Dmin, Dmean, CI and HI of the target region. Superior results were found in bladder V50, rectum V50, Dmean, caput femoris V30 and Dmean with statistical difference （P〈0.05）. The V30, V40, V45 in bladder, V40 in rectum and caput femoris that texted by AP plan were lower than IMRT plan. Conclusions the AP plan could achieve similar target dose distribution to IMRT plan. Meanwhile, the AP plan could lower the highest dose in the target region. The hot spot and the illuminated of OARs were reduced at the same time.