左侧乳腺癌保乳术后VMAT与IMRT剂量比较的Meta分析

A meta-analysis comparing Dosimetric between volumetric-modulated arc therapy and intensity. modulated radiotherapy for left sided breast cancer after breast-conserving surgery

目的对左侧乳腺癌保乳术后VMAT和IMRT靶区与OAR剂量行Meta分析。方法文献检索纳入相关研究。分析靶区和危及器官剂量参数。结果11项研究的154病例纳入Meta分析。PTV-全乳和PTV-瘤床的D mean、均匀性指数均相近（P〉0．05），VMAT计划中PTV-全乳、PTV-瘤床适形性指数值较IMRT计划高（P=0．000、0．002）。当靶区平均体积≤634cm3时，心脏Dmean。V5、V20、V30，左肺Dmean、V5、V20，右肺、右侧乳腺Dmean均无统计学意义（P〉0．05）；当靶区平均体积〉634cm3时，心脏Dmean、V5、V20 IMRT计划优于VMAT（P=0．037、0．005、0．030），V30VMAT计划优于IMRT（P=0．001）。左肺Dmean、V5、V20及右肺Dmea IMRT优于VMAT（P=0．013、0．000、0．000及0．001）。右侧乳腺Dmean也相近（P〉0．05）。结论VMAT和IMRT靶区剂量分布无明显差异。对于危及器官，靶区平均体积≤634cm3时，VMAT和IMRT受量无明显差异；靶区平均体积〉634cm3时，IMRT在心脏、肺的保护上有一定优势。

Objective To compare the dosimetric parameters of target volumes and organs at risk between volumetric-modulated arc therapy （VMAT） and intensity-modulated radiotherapy （IMRT） for left sided breast cancer after breast-conserving surgery by a meta-analysis. Methods Literature search was performed to include related studies to analyze the dosimetric parameters of target volumes and organs at risk. Results A total of 11 studies involving 154 patients were included in recta-analysis. There were no significant differences in D HI of PTV-Whole breast and PTV-Boost. Comparing to IMRT, VMAT increased the conformity index （CI） of PTV-Whole breast （P= 0. 000） and PTV-Boost （ P = 0. 002）.When the mean volume of target volumes was ≤ 634 cm3 , there were no significant differences in Dmean, V5, V20 of the heart and left sided lung , V30 of the heart, D of the right sided lung and breast between VMAT and IMRT.When the mean volume of target volumes was 〉 634 cm3, the Dmean （ P = 0. 037 ） , V5 （ P = 0. 005 ） and V20 （P = 0. 030） of the heart in IMRT was lower than VMAT, but the V30（P = 0. 001 ） of heart in VMAT was lower than IMRT. IMRT showed significantly lower Dmean （ P = 0. 013 ）, V5 （ P = 0. 000）, V20 （ P = 0. 000） of the left sided lung, and Dmean （ P= 0. 001 ） of the right sided lung than VMAT. There were no significant differences in Dmean of the right sided breast. Conclusions There were no significant differences in dosimetric parameters of target volumes between VMAT and IMRT.When the mean volume of target volumes was ≤634 cm3, there were no significant differences in dosimetric parameters of organs at risk. When the mean volume of target volumes was〉634 cm3 , IMRT has some advantages in protection of the heart and lung.