不同类型多叶准直器在宫颈癌容积旋转调强放疗中的剂量学比较  

Dosimetric comparison of different types of multileaf collimators in volumetric modulated arc therapy for cervical cancer

作　　者：李林山 司梦远 杨雪琴 苏坤普 肖姚 周德力 刘岩海 陈川 刘云 LI Linshan;SI Mengyuan;YANG Xueqin;SU Kunpu;XIAO Yao;ZHOU Deli;LIU Yanhai;CHEN Chuan;LIU Yun(Department of Oncology,Army Characteristic Medical Center,Chongqing 400042,China)

机构地区：[1]陆军特色医学中心肿瘤科,重庆400042

出　　处：《重庆医学》2024年第23期3585-3589,共5页Chongqing Medical Journal

基　　金：重庆市科卫联合医学科研项目重点项目(2022ZDXM027,ZDXM20191911)。

摘　　要：目的探讨不同类型多叶准直器(MLC)在宫颈癌容积旋转调强放疗(VMAT)中对靶区和危及器官的剂量学差异。方法选取2023年5月到2024年1月该院接受放疗的20例宫颈癌术后患者为研究对象,为每例患者分别设计Agility TM-MLC和MLCi2-MLC两种宫颈癌术后VMAT计划,比较两种计划靶区(PTV)剂量学参数、危及器官受照剂量、γ通过率和机器跳数(MU)的差异。结果与MLCi2-MLC比较,Agility TM-MLC的V 45、适形性指数(CI)和均匀性指数(HI)更优,差异有统计学意义(P<0.05)。与MLCi2-MLC比较,Agility TM-MLC的膀胱V 30、V 40、平均剂量(D mean),直肠V 10、V 20、V 30,左股骨头V 10、D mean及小肠V 10、V 30、D mean、最大剂量(D max)更低,膀胱V 45、直肠V 45、右股骨头V 20更高,差异有统计学意义(P<0.05)。与MLCi2-MLC比较,Agility TM-MLC的γ通过率更低[(98.31±0.64)%vs.(99.73±0.37)%],差异有统计学意义(P<0.05);而Agility TM-MLC与MLCi2-MLC的MU比较(996.74±65.46 vs.996.80±49.77),差异无统计学意义(P>0.05)。结论Agility TM-MLC的PTV适形性、均匀性及在高、低剂量区对危及器官的保护更好。Objective To investigate the dosimetric differences of different types of multileaf collimators(MLCs)on the planning target volume(PTV)and organs at risk(OARs)in volumetric modulated arc therapy(VMAT)for cervical cancer.Methods Twenty postoperative patients with cervical cancer receiving radiotherapy in this hospital from May 2023 to January 2024 were selected as the study subjects.For each patient,two kinds of VMAT plans(MLCi2-MLC and Agility TM-MLC)after cervical cancer operation were designed.The dosimetric parameters of the planning target volume(PTV),exposure dose by organs at risk(OAR),γpassing rate and monitor units(MU)were compared between the two plans.Results Compared with MLci2-MLC,prescription dose(V 45),conformity index(CI)and homogeneity index(HI)in Agility TM-MLC were better,and the differences were statistically significant(P<0.05),Compared with MLCi2-MLC,bladder V 30,V 40,average dose(D mean),rectal V 10,V 20,V 30,left femoral head V 10,D mean and small intestine V 10,V 30,D mean and D max were lower,bladder V 45,rectal V 45,right femoral head V 20 were higher,and the differences were statistically significant(P<0.05).Compared with MLCi2-MLC,theγpassing rate in Agility TM-MLC was lower[(98.31±0.64)%vs.(99.73±0.37)%],and the difference was statistically significant(P<0.05);while MU had no statistical difference between Agility TM-MLC and MLCi2-MLC(996.74±65.46 vs.996.80±49.77,P>0.05).Conclusion Agility TM-MLC demonstrates better PTV conformity and homogeneity,as well as good protection on OARs in both high and low dose regions.

关 键 词：宫颈癌 多叶准直器 危及器官 容积旋转调强放疗 剂量学 

分 类 号：R730.55[医药卫生—肿瘤]