基于不同多叶准直器的胸膜间皮瘤容积旋转调强放疗剂量学比较  

Dosimetric comparison of volumetric- modulated arc therapy with different multileaf collimators for pleural mesothelioma

作　　者：张富利[1] 蒋华勇[1] 许卫东[1] 王雅棣[1] 高军茂[1] 刘清智[1] 路娜[1] 陈点点[1] 姚波[1] 侯俊[1] 陈建平[1] 

机构地区：[1]北京军区总医院放疗科,北京100700

出　　处：《中国医学物理学杂志》2015年第5期635-638,共4页Chinese Journal of Medical Physics

基　　金：全军医学计量专项课题(2011-JL2-005)

摘　　要：目的:比较基于两种类型多叶准直器(Multileaf Collimator,MLC)的胸膜间皮瘤容积旋转调强放疗(Volumetric Modulated Arc Therapy,VMAT)计划差异。材料与方法:回顾性选取10例因各种无法手术的胸膜间皮瘤患者CT图像,分别采用配置常规多叶准直器(Standar MLC,s MLC)和微型多叶准直器(micro-MLC,m MLC)的医科达直线加速器进行VMAT的计划设计。比较两种计划在靶区(Planning Target Volume,PTV)适形度(Conformity Index,CI)、均匀度(Heterogeneity Index,HI)以及危及器官(Organs At Risk,OAR)剂量体积参数方面的异同。结果:与基于s MLC的VMAT计划(s MLC-VMAT)相比,基于m MLC的VMAT计划(m MLC-VMAT)实施效率高(平均实施时间:2.57±1.66 min vs 3.27±1.65 min,P<0.05)。此外,m MLC-VMAT计划靶区适形度和均匀度优于s MLC-VMAT(CI:0.75±0.08 vs 0.71±0.12;HI:1.09±0.02 vs 1.11±0.03)。就OARs而言,除心脏的Dmean(P=0.042)以外,其它各个OARs的剂量体积参数差异均无显著性意义(P>0.05)。结论:与s MLC-VMAT计划相比,m MLC-VMAT计划不仅明显缩短了治疗时间,提高靶区的覆盖度与均匀性,而且显著降低了心脏的平均受照剂量,有助于减小心血管病的发生风险。Objective To compare the differences of two types of multileaf collimators （MLC） in the volumetric modulated arc therapy （VMAT） plan for pleural mesothelioma. Methods The CT images of ten patients with inoperable pleural mesotheliom were retrospectively selected. The Elekta linear accelerator with Standar MLC （sMLC） and Micro-MLC （mMLC） were respectively applied to design VMAT treatment plans. The conformity index （CI） and homogeneous index （HI） of planning target volume （PTV）, and the dose-volume parameters of organs at risk （OARs） were compared between the VMAT plan with sMLC （sMLC-VMAT） and VMAT plan with mMLC （mMLC-VMAT）. Results The delivery time of sMLC-VMAT and mMLC-VMAT was 3.27 min±1.65 min and 2.57 min±1.66 min, respectively. Compared with sMLC-VMAT, mMLC-VMAT was more efficient （P〈0.05）. And the CI of sMLC-VMAT and mMLC-VMAT was 0.71±0.12, 0.75±0.08, respectively, while the HI was 1.11±0.03, 1.09±0.02, respectively. Both HI and CI of mMLC-VMAT were better than those of sMLC-VMAT. No significant differences were found in the dose-volume parameter of OARs （P〉0.05）, except the mean dose of heart （P=0.042）. Conclusion Compared with the sMLC-VMAT, mMLC-VMAT can reduce the treatment delivery time, improve the coverage and HI of target volumes, significantly reduce the average irradiation dose to heart, and lower the risk of cardiovascular disease.

关 键 词：多叶准直器 胸膜间皮瘤 容积旋转调强放疗 放疗剂量 

分 类 号：R734.3[医药卫生—肿瘤] R730.55[医药卫生—临床医学]