胸膜间皮瘤螺旋断层调强放疗与两种容积旋转调强放疗计划的剂量学评估？  

Dosimetric evaluation of helical tomotherapy and two types of volumetric modulated arc therapy for malignant pleural mesothelioma

作　　者：张富利[1] 许卫东[1] 蒋华勇[1] 王雅棣[1] 高军茂[1] 刘清智[1] 

机构地区：[1]北京北京军区总医院放疗科,100700

出　　处：《临床肿瘤学杂志》2015年第8期741-744,共4页Chinese Clinical Oncology

基　　金：全军医学计量专项课题资助(2011-JL2-005)

摘　　要：目的比较螺旋断层调强放疗(helical tomotherapy,HT)和基于两种加速器的容积旋转调强放疗(volumetric modulated arc therapy,VMAT)在恶性胸膜间皮瘤放疗中的剂量学差异。方法回顾性分析10例无法手术的胸膜间皮瘤患者CT图像,采用Elekta Synergy(S-VMAT)和Elekta Axesse加速器(A-VMAT)进行VMAT放疗计划以及螺旋断层放疗系统完成HT放疗计划的设计,要求95%的计划靶区(PTV)达到处方剂量60 Gy。比较3种计划在靶区适形度指数(CI)、均匀性指数(HI)、最大剂量(Dmax)、最小剂量(Dmin)、平均剂量(Dmean)以及危及器官(OARs)剂量体积参数方面的差异。结果 HT计划的Dmax、Dmean显著低于S-VMAT和A-VMAT(P<0.001,P=0.002),而Dmin和CI的差异均无统计学意义(P>0.05)。此外,HT计划的靶区HI显著优于S-VMAT和A-VMAT(1.04±0.01 vs.1.11±0.03 vs.1.09±0.02,P<0.001);CI也优于后两者,但差异无统计学意义(0.80±0.07 vs.0.71±0.12 vs.0.75±0.08,P>0.05)。3组计划的OARs剂量体积参数的差异均无统计学意义(P>0.05)。与HT计划比较,S-VMAT和A-VMAT计划的平均实施时间大幅减少[(11.11±3.75)min vs.(3.27±1.65)min vs.(2.57±1.66)min,P<0.05]。结论 VMAT计划在靶区覆盖度与均匀性方面略逊于HT,但治疗时间明显缩短,有利于提高患者治疗过程中的舒适度和重复性。Objective To compare the impacts of helical tomotherapy （ HT） and two types of volumetric modulated arc thera.py （ VMAT） planning for the malignant pleural mesothelioma based on the Elekta Synergy linac （ S.VMAT） and the Elekta Axesse lin.ac （ A.VMAT） , respectively. Methods Ten patients with inoperable malignant pleural mesothelioma were retrospectively planned with the HT, S.VMAT and A.VMAT. Dose volume histogram.based parameters of the planning target volume （ PTV ） including the maximum dose （ Dmax ） , the minimum dose （ Dmin ） , the average dose （ Dmean ） , conformity index （ CI） and homogeneous index （ HI） as well as organs at risks （ OARs） were compared among the 3 plans. Results The HT plan provided lower Dmax and Dmean（ P〈0.001, P=0.002） while Dmin was similar （ P〉0.05） . Compared to S.VMAT and A.VMAT plans, the HT plan showed advantages in HI and CI （HI：1.04±0.01 vs. 1.11±0.03 vs. 1.09±0.02, P〈0.001;CI：0.80±0.07 vs. 0.71±0.12 vs. 0.75±0.08, P〉0.05）. As far as the OARs were concerned, the differences among the HT, S.VMAT and A.VMAT plans were not significant （ P〉0.05） . In addition, com.pared to the HT plan, the S.VMAT and A.VMAT plans were more efficient[mean delivery time： （11.11±3.75） min vs. （3.27± 1.65）min vs.（2.57±1.66）min, P〈0.05]. Conclusion VMAT plans are slightly inferior to HT plans in the target dose heterogeneity and conformity. However, the treatment delivery time of the VMAT plans were greatly reduced, which is conducive to improving the patients. comfortability and repeatability during the treatment.

关 键 词：胸膜间皮瘤 螺旋断层调强放疗( HT) 容积旋转调强放疗 ( VMAT) 

分 类 号：R734.3[医药卫生—肿瘤]