靶区形变在体部立体定向放射治疗三维适形计划设计中的应用研究  

Application of target deformation method in design for 3⁃dimensional conformal plan of stereotactic body radiotherapy

作　　者：吴魁[1] 水永杰[1] 张怀文[2] WU Kui;SHUI Yongjie;ZHANG Huaiwen(Department of Radiation Oncology,the Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou 310009,China;不详)

机构地区：[1]浙江大学医学院附属第二医院放疗科,杭州310009 [2]江西省肿瘤医院放疗中心,南昌330029

出　　处：《实用医学杂志》2020年第23期3293-3296,共4页The Journal of Practical Medicine

基　　金：浙江省自然科学基金(编号:LQ18H160013)。

摘　　要：目的本文提出一种新的体部立体定向放射治疗(stereotactic body radiotherapy,SBRT)的三维适形计划设计方法并评估其剂量学优势。方法随机选30例以SBRT技术治疗的患者进行回顾性分析研究,每位患者分别设计常规三维适形计划(conventional 3⁃dimensional conformal planning,CCP)和靶区形变后的三维适形计划(deformed target 3⁃dimensional conformal planning,DCP)。每个计划的处方剂量定义为计划靶区(PTV)50 Gy/5次,且要求95%的PTV体积达到处方剂量。比较两种计划适形指数(CI)、剂量梯度(DG)、靶区近似最小剂量(D99%)、离靶区2 cm处最大剂量(D2 cm)和机器跳数(MU)的差异。结果两组计划均能达到临床治疗的要求。但DCP与CCP相比,CI、DG、D99%、和D2 cm有明显改善(t=4.55、5.95、4.37、3.86,P<0.05),MU也大幅减少(t=2.82,P<0.05)。结论DCP剂量学优势明显,且机器跳数显著减少,大幅缩短治疗时间,可以作为一种新的计划设计方法加以推广。Objective A new method of 3⁃dimensional conformal planning design is proposed and its dosimetric advantages in stereotactic body radiotherapy(SBRT)are evaluated.Methods A retrospective study was conducted in 30 patients treated with SBRT technology.The conventional 3⁃dimensional conformal planning(CCP)and the deformed target 3⁃dimensional conformal planning(DCP)were designed respectively.The prescription dose of each plan is defined as the planning target volume(PTV)50 Gy/5 fractions,and the PTV coverage was required to be>95%for prescription dose.The plans were compared by assessing the conformity index(CI),dose gradient(DG),approximate minimum dose of PTV(D99%),maximum dose at 2 cm from PTV in any direction(D2 cm)and monitor unit(MU).Results Both groups of plans satisfied all clinical requirements.CI,DG,D99%,and D2 cm in the group DCP were significantly improved(t=4.55,5.95,4.37,3.86,P<0.05)and MU decreased(t=2.82,P<0.05)compared with the group CCP.Conclusions DCP has obvious dosimetric advantages,and reduces the number of MU while shortening the treatment time.It can be promoted as a new planning design method.

关 键 词：体部立体定向放射治疗 三维适形计划 剂量梯度 适形指数 

分 类 号：R730.55[医药卫生—肿瘤]