剂量沉积方式在食管癌放疗中的差异性研究  

Impact of statistical uncertainty on esophagus cancer plan for dose to water and dose to medium

作　　者：王芸[1] 顾培华[1] 汪杰华[1] 曹粲 李晴昊 陈利[2] 张肖肖[2] 王璐[2] WANG Yun;GU Peihua;WANG Jiehua;CAO Can;LI Qinghao;CHEN Li;ZHANG Xiaoxiao;WANG Lu(Department of Radiotherapy,Shanghai Shidong Hospital,Shanghai 200438 China;Department of Radiotherapy,Anshan Cancer Hospital,Anshan 114000 China)

机构地区：[1]上海市杨浦区市东医院,上海200438 [2]鞍山市肿瘤医院,辽宁鞍山114000

出　　处：《中国辐射卫生》2021年第3期295-302,共8页Chinese Journal of Radiological Health

基　　金：基于X射线体素蒙特卡洛算法的多因素临床计划应用研究(20200789)。

摘　　要：目的研究Monaco计划系统(Monaco Treatment planning system,Monaco TPS)应用不同剂量沉积方式的情况下,对中下段食管癌放射治疗的剂量学影响。方法选取30例T_(3)N_(0)M_(0)Ⅱa期中下段食管癌患者进行实验,使用瑞典医科达公司Monaco 5.11TPS的X射线体素蒙特卡洛(X-Ray Voxel Monte Carlo,XVMC)算法,对每例入组病例分别以Dose to water(D_(w))和Dose to medium(D_(m))剂量沉积方式进行计划设计。在处方剂量均覆盖计划靶区(Planning target volume,PTV)95%体积的情况下,比对D_w和D_m2种情况下的计划优化时间,PTV的适形指数(Conformity index,CI)和均匀性指数(Homogeneity index,HI)以及平均剂量D_(mean)、最小剂量D_(min)、最大剂量D_(2),危机器官(Organ at risk,OAR)受量,计划实施跳数(#MU),计划优化时长(s),光子利用率(%)和在MatriXX二维矩阵及ArcCheck三维验证模体下的验证结果差异;使用SPSS 22.0进行统计分析。结果中下段食管癌病例在不同剂量沉积方式下的剂量结果评估中,脊髓、气管的剂量结果、全肺外壁V_(20)的体积百分比和肝的D_(2)存在统计学差异,依次剂量结果对比为(37.92±1.11)/(35.85±1.08)、(59.91±1.43)/(60.25±0.98)、(22.52±1.75)/(21.38±2.01)、(42.89±0.52)/(41.73±0.58);在剂量云图分布对比中,差异主要表现在靶区内空腔和肺内壁与外壁,靶内空腔剂量D_w组高于D_m组,肺空腔内壁及外壁D_(w)组比D_(m)组略为内收,空腔中心区域略为突出;不同剂量沉积方式的30例60个计划的MartiXX二维测量矩阵(3%-3 mm)和Arc Check 4D模体(2%-2 mm)的验证结果通过率均符合临床要求,D_(m)组优于D_(w)组。结论应用Monaco5.11 TPS进行中下段食管癌放射治疗计划时,在剂量沉积方式的选择上,推荐使用D_(m)方式。Objective To study the dosimetry effect of D_(w) and D_(m) middle and lower esophageal cancer in Monaco treatment planning system(TPS).Methods 30 patients with T3N0M0StageⅡa middle and lower esophageal cancer were selected for experiment.For each patient,optimize the plan using dose to water(D_(w))and dose to medium(D_(m))dose calculation mode,then rescale prescription dose to 95%volume of PTV.Compare the difference in the two mode,conformity index(CI),Homogeneity index(HI),Mean dose(D_(m)ean),Minimum dose(D_(m)in),Maximum dose(D2),Dose to Organ at risk(OAR),MU,Optimization time,photon usage,and QA results of MatriXX and Arc Check.Use SPSS for multivariate analysis.Results In the dose evaluation of the middle and lower esophageal cancer cases under different dose calculation methods,the spinal cord,trachea,V20 of the whole lung,and D2 of the liver have significant dosimetric differences,the dose value,the sequential dose results were compared as(37.92±1.11)/(35.85±1.08),(59.91±1.43)/(60.25±0.98),(22.52±1.75)/(21.38±2.01),(42.89±0.52)/(41.73±0.58).In the comparison of dose cloud distribution,the difference is mainly located in the cavity and the inner wall of the lung in the target area,the dose in the target cavity in the D_(w) group is higher than that in the D_(m) group.The dose in the inner and outer walls of the lung cavity in the D_(w) group are slightly adducted than that in the D_(m) group,especially in the central area.Dose QA of MartiXX(3%-3 mm)and Arc Check(2%-2 mm)with different dose calculation methods of 60 plans of 30 cases have all passed clinical requirements.D_(m) Group is better than D_(w) group.Conclusion It is recommended to use D_(m) dose calculation method for Monaco 5.11 TPS in the condition of treatment planning for middle and lower esophageal cancer.

关 键 词：Dose to Water Dose to Medium 双段弧容积调强 中下段食管癌 X射线体素蒙特卡洛 

分 类 号：R816[医药卫生—放射医学]