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AgilityTM-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、7通过率和机器跳数(MU)的差异.结果 与MLCi2-MLC比较,AgilityTM-MLC的V45、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,AgilityTM-MLC 的膀胱 V30、V40、平均剂量(Dmean),直肠 V10、V20、V30,左股骨头 V10、Dmean 及小肠 V10、V30、Dmean、最大剂量(Dmax)更低,膀胱V45、直肠V45、右股骨头V20更高,差异有统计学意义(P＜0.05).与MLCi2-MLC 比较,AgilityTM-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 AgilityTM-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 AgilityTM-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.
Abstract
Objective To investigate the dosimetric differences of different types of multileaf collima-tors(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 pa-tient,two kinds of VMAT plans(MLCi2-MLC and AgilityTM-MLC)after cervical cancer operation were de-signed.The dosimetric parameters of the planning target volume(PTV),exposure dose by organs at risk(OAR),y passing rate and monitor units(MU)were compared between the two plans.Results Compared with MLci2-MLC,prescription dose(V45),conformity index(CI)and homogeneity index(HI)in AgilityTM-MLC were better,and the differences were statistically significant(P＜0.05),Compared with MLCi2-MLC,bladder V30,V40,average dose(Dmean),rectal V10,V20,V30,left femoral head V10,Dmean and small intestine V10,V30,Dmean and Dmax were lower,bladder V45,rectal V45,right femoral head V20 were higher,and the differences were statistically significant(P＜0.05).Compared with MLCi2-MLC,the y passing rate in AgilityTM-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 AgilityTM-MLC and MLCi2-MLC(996.74±65.46 vs.996.80±49.77,P＞0.05).Conclusion AgilityTM-MLC demonstrates better PTV conformity and homogenei-ty,as well as good protection on OARs in both high and low dose regions.
维普
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