基于VMAT和IMRT在宫颈癌根治放疗中的剂量学差异分析

Analysis of Dosimetric Differences in Cervical Cancer Radical Radiotherapy Based on VMAT and IMRT

目的:探讨容积旋转调强放疗(VMAT)和逆向调强放疗技术(IMRT)在宫颈癌根治放疗中的剂量学差异。方法:选取2020年1月至2022年12月在我院治疗的51例宫颈癌患者为研究对象,对所有患者进行IMRT和VMAT放疗设计。比较两种放疗技术的靶区剂量、机器跳数、治疗时间以及危及器官剂量分布。结果:VMAT的适形度指数(CI)高于IMRT,均匀性指数(HI)低于IMRT,差异有统计学意义(P<0.05)。VMAT技术的机器跳数少于IMRT,治疗时间短于IMRT,差异有统计学意义(P<0.05)。危及器官剂量分布比较结果显示,股骨头剂量分布中,VMAT的V_(20)、D_(mean)低于IMRT;小肠和盆骨骨髓的剂量分布中,VMAT的V_(20)、V_(30)、D_(mean)低于IMRT;直肠剂量分布中,VMAT的V_(20)低于IMRT;膀胱剂量分布中,VMAT的D_(mean)低于IMRT;差异均有统计学意义(P<0.05)。结论:VMAT可以获得与IMRT相当的靶区剂量分布,而且VMAT的靶区适形度、剂量均匀性更佳,更利于保护危及器官。

Objective:To explore the dosimetric differences between VMAT and IMRT in cervical cancer radical radiotherapy.Methods:51 cervical cancer patients who were treated in our hospital from January 2020 to December 2022 were selected as the research subjects,and all patients were subjected to IMRT and VMAT radiotherapy designs.The target dose,machine hops,treatment time,and dose distribution of organs at risk were compared between two radiotherapy techniques.Results:The CI of VMAT was higher than that of IMRT,while the HI was lower than that of IMRT,with a statistically significant difference(P<0.05).The monitor units of VMAT technology is less than that of IMRT,and the treatment time is shorter than that of IMRT,with a statistically significant difference(P<0.05).The comparative results of the dose distribution of organs at risk showed that in the dose distribution of the femoral head,the V_(20) and D_(mean) of VMAT were lower than those of IMRT;In the dose distribution of small intestine and pelvic bone marrow,the V_(20),V_(30),and Dmemean of VMAT were lower than those of IMRT;In the rectal dose distribution,the V_(20) of VMAT is lower than that of IMRT;In the bladder dose distribution,the D_(mean) of VMAT is lower than that of IMRT;The differences were statistically significant(P<0.05).Conclusion:VMAT can obtain a target dose distribution comparable to IMRT,and its target conformal index and dose uniformity are better,which is more conducive to protecting endangered organs.