容积旋转调强放射治疗在直肠癌患者中的应用  

The Application of Volumetric Modulated Arc Therapy in Patients with Rectal Cancer

作　　者：花威[1] 张先稳[1] 茅冬俊[1] 陈婷婷[1] Hua Wei;Zhang Xianwen;Mao Dongjun;Chen Tingting(Department of Oncology,Northern Jiangsu People's Hospital,Yangzhou Jiangsu 225001,China)

机构地区：[1]江苏省苏北人民医院肿瘤科,江苏扬州225001

出　　处：《医疗装备》2022年第6期5-8,共4页Medical Equipment

摘　　要：目的探讨容积旋转调强放射治疗(VMAT)在直肠癌患者中的应用效果。方法回顾性分析2019年11月至2020年12月于医院行放射治疗的10例直肠癌患者的临床资料,对其设计VMAT计划,处方剂量为5000 cGy,通过COMPASS系统对计划进行验证,并利用剂量体积直方图对计划靶区(PTV)、危及器官(OARs)的各指标进行评价。结果等中心绝对剂量的准确率达(99.12±0.73)%;PTV的γ通过率达95%以上,OARs的γ通过率达96%以上。PTV的靶区均匀性指数(HI)、靶区适形度指数(CI)分别为(1.06±0.03)、(0.90±0.05),均匀性和适形度均较好,接受95%处方剂量的体积百分比V_(95%)为(97.93±1.21)%,剂量验证结果显示,PTV各评价指标差异在4.3%以内;OARs的评估参数均满足放射治疗临床剂量学要求,其中,膀胱和小肠受照40 Gy剂量的体积V_(40)仅为(20.31±4.23)%和(7.81±3.15)%,低剂量区V_(20)为(92.22±4.33)%和(51.24±4.41)%,平均受照剂量D_(mean)分别为(2772.54±235.82)cGy和(2425.75±176.72)cGy,小肠的最大受照剂量D_(max)稍高,为(4567.44±156.43)cGy,股骨头5%的体积受照剂量D_(5%)也在4000 cGy以内,剂量验证结果显示,膀胱、小肠、股骨头的各指标差异在4.4%以内。结论VMAT能够满足直肠癌放射治疗的临床剂量学要求。Objective The application effect of volumetric modulated arc therapy(VMAT)in patients with rectal cancer was investigated.Methods The clinical data of 10 patients with rectal cancer undergoing radiotherapy in the hospital from November 2019 to December 2020 were analyzed retrospectively.VMAT plans were designed for them and the prescription dose was 5000 cGy.The COMPASS dose verification system was used to verify these plans.The indexes of planning target volume(PTV)and organs at risk(OARs)were evaluated with dose-volume histograms.Results The accuracy of the absolute dose at the isocenter was(99.12±0.73)%,the γ passing rate of PTV was over 95%,and theγpassing rate of OARs was over 96%.The homogeneity index(HI)and conformity index(CI)of target volume for PTV were(1.06±0.03)and(0.90±0.05)respectively,indicating that both uniformity and fitness were good.The volume percentage for accepting 95% prescription dose(V_(95%))was(97.93±1.21)%.The results of dose verification showed that the differences of all evaluation indexes of PTV were less than 4.3%.The evaluation indexes of OARs could all meet the requirements of clinical dosimetry requirements for radiotherapy.Among them,the volumes of accepting 40 Gy doses(V_(40))for bladder and small intestine were only(20.31±4.23)%and(7.81±3.15)%.The V_(20) of low dose area were(92.22±4.33)% and(51.24±4.41)%.The mean doses(D_(mean))were(2772.54±235.82)cGy and(2425.75±176.72)cGy.The max dose(D_(max))of small intestine was slightly higher,which was(4567.44±156.43)cGy.The dose of 5% volume(D_(5%))for femoral head was also less than 4000 cGy.The results of dose verification showed that the differences of all evaluation indexes of bladder,small intestine and femoral head were all within 4.4%.Conclusion VMAT could satisfy the clinical dosimetry requirements of radiotherapy for rectal cancer.

关 键 词：直肠癌 容积旋转调强放射治疗 剂量体积直方图 剂量验证 

分 类 号：R730.55[医药卫生—肿瘤]