宫颈癌IMRT同步剂量补偿高剂量率后装中CT参考点与固定等中心计划研究  

A Study of the CT Reference Point and Isocenter of Plan on HDR Brachytherapy with Concomitant Complementary IMRT Boost for Cervix Carcinoma

作　　者：刘敏 王先良 王首龙 康盛伟 杨凤 汤婷 黎杰 王培 Liu Min;Wang Xianliang;Wang Shoulong;Kang Shengwei;Yang Feng;Tang Ting;Li Jie;Wang Pei(Radiation Oncology Key Lab of Sichuan Province,Sichuan Cancer Hospital&Institute,Sichuan Cancer Center,School of Medicine,University of Electronic Science and Technology of China,Chengdu 610041,Sichuan,China)

机构地区：[1]四川省肿瘤医院·研究所,四川省癌症防治中心,电子科技大学医学院放射肿瘤学四川省重点实验室,成都610041

出　　处：《肿瘤预防与治疗》2021年第1期75-82,共8页Journal of Cancer Control And Treatment

基　　金：国家重点研发计划项目(编号:2017YFC0113100);四川省科技重点研发项目(编号:2018GZ0197)。

摘　　要：目的∶研究宫颈癌调强放射治疗(mtnity modulation ndain herapy,IMRT)同步剂量补偿高剂量率后装中CT参考点与计划等中心位置重合的可能性,以简化流程,改进临床工作。方法∶回顾性分析12例Ⅱ~Ⅲ。期的宫颈癌患者,比较患者以CT参考点为等中心与原临床计划以中危靶区(inemediterik clical arge volume,IRCTV)几何中心为等中心两种情况下剂量参数的区别,统计患者IRCTV几何中心距离耻骨联合上缘处距离。结果∶两种治疗计划在CT参考点与IRCTV几何中心距离较近时均能满足临床要求,靶区适形性指数(Cl)以及小肠剂量无统计学差异。但将CT参考点设置为等中心会让高危靶区(hig rik clinical urget volume,HRCTV)中D100%,D90%,D50%增加的同时(P<0.05),也会一定程度增加膀胱和直肠D0.1cc,D1cc,D2cc值(P<0.05)。同时随着CT参考点与IRCTV几何中心之间距离的增加,IRCTV中D100%,D50%,CI与HRCTV中D90%,D50%,CI的偏差均有随着距离增加面增大趋势,其中对靶区Dm影响最大,IRCTV最大偏差达到10.04%,HRCTV最大偏差达到12.68%。接受根治放疗的患者与术后患者RCTV几何中心与耻骨联合上缘处相对距离∶X方向分别为(-0.07±0.67)cm,(-0.09±0.55)cm(P=0.823);Y方向分别为(2.58±1.07)cm,(1.23±0.99)cm(P<0.05);Z方向分别为(-7.17±0.91)m,(-6.84±0.90)cm(P<0.05)。结论∶在宫颈癌IMRT同步剂量补偿高剂量率后装治疗中,X方向按照体表中线,Y方向根治与术后患者分别按照趾骨联合上缘处患者头方向2.58 cm和1.23cm,Z方向分别按照耻骨联合上缘下方7.17 cm和6.84cm进行CT定位,能减少CT参考点与IRCTV几何中心的相对距离。在此基础上,可考虑在治疗过程中直接将CT参考点设置为计划等中心。Objective:To study the psibility of the overlap between CT reference point and iscenter in high-dose rate(HDR)brachytherapy with conconitant complemnentary intensity modulation radiation therapy(IMRT)boost for cervix carei-noma,so as 10 simplifty clinical process and improve fficieney.Methods:Retrospective analyis was made on 112 cases of stuge IA-Ig cervical cancer.The plan with the CT reference poin as isocenter(the CT group)and that with the gommet-ric center of intermediate risk elinical target volume(IRCTV)as isocenter(the IRCTV group)were compured.The distance between the geonetric center of IRCTV and the superior margin of the pubic symphysis were evaluated.Resuls:Both two plans met clinical requirements for dosimety.There were mo sgnifcant difrences in conformity index(CI)of target and in-testine radiation dose between two conditions.Values of D100%,D90%,D50% of high risk clinical target volume(HRCTV)and Date,De,D2.of bladder and rectum in the CT group were higher than those in the IRCTV group(P<0.05)。In the meanwhile,as the distance between the geometric center of IRCTV and the CT reference point grew,the deviation of D00m,.Dsos,CI of IRCTV and that ofDyo%,Dom,CI of HRCTV increased.The most signifcant varistion ocurred in the value of Dgo of targts.The maximum deviation of IRCTV and HRCTV were 10.04%and 12.68%,respectively.The distances be-tween the geonetrie center of IRCTV and the superior margin of the pubie symphysis in patients undergoing radical radiother-apy u postoperative patients were(-0.07±0.67)cmus(-0.09±0.55)cm in the X direction(P=0.823),(2.58±1.07)cm us(1.23±0.99)cm in the Y direction(P<0.05),(-7.17±0.91)emu(-6.84±0.90)cm in the Z di-rection(P<0.05),(7.73±0.86)cm ts(7.03±0.93)cm in the D drction(P<0.05),resectively.Conclusion:During the process of HDR brachytherapy with concomitant complementary IMRT boost for cervix carcinomna,the CT refer-ence point should be set in the midle line of the body surface(X dretion);it should be set al 2.58 cm and 1.23 cm in the superior margin of t

关 键 词：后装 同步剂量补偿 CT 参考点 等中心 距离 

分 类 号：R737.33[医药卫生—肿瘤] R730.55[医药卫生—临床医学]