不同射线能量的两种调强技术在直肠癌术前放疗中的应用比较  

Dosimetric comparison of volumetric modulated arc therapy and intensity-modulated radiotherapy with different energy photons in preoperative radiotherapy rectal cancer

作　　者：张武哲[1] 黄宝添[1] 严立基 彭逊[1] ZHANG Wu-Zhe;HUANG Bao-Tian;YAN Li-Ji(Department of Radiation Oncology Cancer Hospital of Shantou University Medical College,Shantou 515031,Guangdong,China)

机构地区：[1]汕头大学医学院附属肿瘤医院放疗科,广东汕头515031

出　　处：《中国老年学杂志》2019年第4期796-799,共4页Chinese Journal of Gerontology

基　　金：国家自然科学基金资助项目(81602667)

摘　　要：目的比较不同射线能量的两种调强技术在直肠癌术前放疗中的剂量学特点。方法回顾性选取18例直肠癌术前放疗患者,在Eclipse计划系统上设计4组计划:6 MV和10 MV各自的单弧容积旋转调强(VMAT)和5野逆向动态调强(IMRT)。通过剂量体积直方图(DVH)比较靶区和危及器官等剂量分布。结果 10 MV IMRT的适形度指数(CI)最优,更接近1,但其与10 MV VMAT差异无统计学意义(P>0. 05)。6MV VMAT的均匀性指数(HI)比其他三组略差,差异有统计学意义(P<0. 05),10 MV VMAT的HI与6 MV IMRT的差异无统计学意义(P>0. 05),但比10 MV IMRT略高,差异有统计学意义(P<0. 05)。VMAT组中小肠的V20、双侧股骨头的Dmean、V20、V30明显低于IMRT组,差异有统计学意义(P<0. 05),小肠的V30、膀胱的Dmean、D5、V30高于IMRT组,差异有统计学意义(P<0. 05)。10 MV VMAT B-P的V5、V10明显高于IMRT组,差异有统计学意义(P<0. 05),其V20明显低于IMRT组,差异有统计学意义(P<0. 05)。MU:6 MV的VMAT较IMRT减少了61%,10 MV的VMAT较IMRT减少了51%(P<0. 05)。TT:6 MV的VMAT较IMRT缩短了73%,10 MV的VMAT较IMRT缩短了50%,差异有统计学意义(P<0. 05)。结论 4组计划均能满足临床剂量学要求,10 MV VMAT与IMRT组均能保证靶区剂量,保护盆腔脏器,在部分危及器官上10MV VMAT稍占优势且能更好地降低MU和缩短TT。Objective To compare the dosimetric difference of volumetric modulated arc therapy(VMAT)and intensity-modulated radiotherapy(IMRT)for preoperative radiotherapy rectal cancer with different energy photons.Methods 6 MV and 10 MV single VMAT and 5-field IMRT plans were designed to 18 rectal cancer patients with preoperative radiotherapy by planning treatment system(Eclipse 10.0),respectively.The dose volume histogram(DVH),target and risk organ doses,were compared between the difference kinds of plans.Results IMRT plans with 10 MV provided the best CI,but no significant difference as compared with 10 MV VMAT plans.VMAT plans with 6 MV had the lowest HI(P<0.05),10 MV VMAT plans had similar HI as compared with 6 MV IMRT plans,but higher HI than 10 MV IMRT plans(P<0.05).The V20 of small intestine and the Dmean,V20 and V30 of femoral head in VMAT plans were lower than those in IMRT plans(P<0.05),however,the V30 of small in testine and the Dmean,D5,V30 of bladder inVMAT plans were higher than those in IMRT plans(P<0.05).VMAT plans with 10 MV had higher B-P V5,V10 and lower V20(P<0.05),as compared with those of IMRT plans.6 MV VMAT plans reduced the monitor unit(MU)by 61%,as well as the treatment time(TT)by 73%,as compared with IMRT plans.10 MV VMAT plans reduced MU by 51%,as well as TT by 50%,as compared with those of IMRT plans.Conclusions All the VMAT and IMRT plans can satisfactorily meet the requirement of clinical dosimetry.10 MV VMAT and IMRT plans could ensure the target dose and protect the pelvic organs,10 MV VMAT plans could show part of organs sparing,reduce its MU and TT.

关 键 词：直肠癌 不同能量 容积旋转调强 动态调强 

分 类 号：R735.3[医药卫生—肿瘤]