VMAT与DCAT计划在脑寡转移瘤分次立体定向放疗中的剂量学比较  

Dose comparison of VMAT and DCAT plans in fractionated stereotactic radiotherapy for brain oligometastases

作　　者：李洁 刘苓苓[1,2,3] 崔相利 李兵兵[1,2] 费振乐 韩伟[2] LI Jie;LIU Lingling;CUI Xiangli;LI Bingbing;FEI Zhenle;HAN Wei(Radiotherapy Center,Hefei Cancer Hospital,Chinese Academy of Sciences,Hefei,Anhui 230031,China;Institute of Health and Medical Technology,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei,Anhui 230031,China;Science Island Branch,University of Science and Technology of China,Hefei,Anhui 230031,China;Department of Oncology,the 901st Hospital of Joint Logistics Support Force of the Chinese People's Liberation Army,Hefei,Anhui 230031,China)

机构地区：[1]中国科学院合肥肿瘤医院放疗中心,安徽合肥230031 [2]中国科学院合肥物质科学研究院健康与医学技术研究所,安徽合肥230031 [3]中国科学技术大学研究生院科学岛分院,安徽合肥230031 [4]中国人民解放军联勤保障部队第901医院肿瘤诊疗中心,安徽合肥230031

出　　处：《中华肿瘤防治杂志》2023年第21期1272-1278,共7页Chinese Journal of Cancer Prevention and Treatment

基　　金：国家自然科学基金(82202945);安徽省自然科学基金(2208085MA13);中国科学院合肥肿瘤医院优秀医学青年人才计划(2000000005)。

摘　　要：目的比较脑寡转移瘤分次立体定向放射治疗中容积旋转调强放射治疗(VMAT)与动态适形弧放射治疗(DCAT)计划的剂量学特点,为临床治疗方式的选择提供参考。方法纳入2020-07-08-2022-05-27中国科学院合肥肿瘤医院收治的20例脑寡转移瘤患者,采用相同计划参数分别优化VMAT与DCAT计划,当靶区剂量覆盖率相同时,采用Wilcoxon符号秩检验比较靶区与危及器官剂量、机器跳数(MU)、控制点数(CP)及计划复杂度(MU/CP)等指标差异,采用Spearman相关性分析评估靶区球形度与2种计划剂量参数的相关性。结果VMAT计划靶区适形度指数(0.87±0.07)高于DCAT计划(0.65±0.08),梯度指数(4.97±1.00)低于DCAT计划(6.78±1.26),剂量均匀性指数(1.08±0.01)亦低于DCAT计划(1.15±0.04),Z值均为-3.920,均P<0.001。VMAT计划健康脑组织的V_(12 Gy)、V_(19.6 Gy)和V_(23.1 Gy)分别为(87.72±23.62)、(36.01±9.45)和(24.66±7.39)cm^(3),均低于DCAT计划,Z值均为-3.920,均P<0.001。DCAT计划的MU为763.17±40.12,CP为65.95±15.78,低于VMAT的1153.75±241.72和162.55±11.48,Z值分别为-3.920和-3.922,均P<0.001;MU/CP为12.45±4.15,高于VMAT的2.61±0.68,Z=-3.920,P<0.001。DCAT计划的靶区球形度与梯度指数呈中等正相关,r_(s)=0.465,P=0.039。结论VMAT和DCAT均能满足临床剂量限制要求,但VMAT具有更优靶区适形度、剂量梯度和剂量均匀性,对健康脑组织的保护更佳,而DCAT执行效率更高。对于需高度适形和正常组织保护的患者,优先推荐VMAT,而对于长时间放疗耐受性差的患者,可考虑选用DCAT。Objective To compare the dosimetric characteristics of volumetric modulated arc therapy(VMAT) and dynamic conformal arc therapy(DCAT) plans in fractionated stereotactic radiotherapy for brain oligometastases,and provide a reference for the selection of clinical treatment methods.Methods A total of 20 patients with oligometastatic brain tumors admitted to Hefei Cancer Hospital of the Chinese Academy of Sciences from July 8th,2020to May 27th,2022were included.The VMAT and DCAT plans were optimized using the same plan parameters.When the target dose coverage was the same,the Wilcoxon signed rank test was used to compare the differences of parameters between the two plans,including doses in the target and organs at risk,monitor units(MU),control points(CP),and plan complexity(MU/CP).The Spearman correlation analysis method was used to evaluate the correlation between target sphericity and dose parameters in the two plans.Results The target conformity index(0.87±0.07)of the VMAT plan was higher than that of the DCAT plan(0.65±0.08),the gradient index(4.97±1.00)was lower than that of the DCAT plan(6.78±1.26),and the dose homogeneity index(1.08±0.01)was also lower than that of the DCAT plan(1.15±0.04),all Zvalues were-3.920,all P<0.001.The V12Gy,V19.6Gyand V23.1Gyof healthy brain tissue in the VMAT plan were(87.72±23.62),(36.01±9.45)and(24.66±7.39)cm3,respectively,which were lower than those in the DCAT plan,all Zvalues were-3.920,all P<0.001.The MU of the DCAT plan was 763.17±40.12,the CP was 65.95±15.78,which were lower than those of the VMAT plan's 1 153.75±241.72and 162.55±11.48,Zvalues were-3.920and-3.922,respectively,both P<0.001;MU/CP was 12.45±4.15,higher than the VMAT plan's 2.61±0.68,Z=-3.920,P<0.001.The sphericity of the target in the DCAT plan was moderately positively correlated with the gradient index,rs=0.465,P=0.039.Conclusions Both VMAT and DCAT can meet clinical dose constraints.However,VMAT demonstrates superior target conformity,dose gradient and dose homogeneity,resulting in better pr

关 键 词：容积旋转调强放射治疗 动态适形弧放射治疗 脑转移瘤 分次立体定向放射治疗 剂量学 

分 类 号：R739.41[医药卫生—肿瘤]