鼻咽癌原发肿瘤靶区勾画的差异分析  

Analysis of Differences on Delineation of the Gross Tumor Volume (GTV) of Nasoph aryngeal Carcinoma

作　　者：彭逊[1] 林志雄[1] 林伟彬[2] 李德锐[1] 洪红光[1] 

机构地区：[1]汕头大学医学院附属肿瘤医院鼻咽癌专科,广东汕头515031 [2]汕头大学医学院附属肿瘤医院放射科,广东汕头515031

出　　处：《癌症》2004年第z1期1528-1531,共4页Chinese Journal of Cancer

摘　　要：背景与目的:以CT模拟定位(CTsim)为基础的现代放射治疗计划设计要求准确勾画肿瘤靶区及重要危险器官,这是提高鼻咽癌患者治疗效果及生存质量的重要保障。本研究通过比较不同医生对鼻咽癌原发大体肿瘤靶区(GTV)勾画的差异,分析影响鼻咽癌GTV勾画的主要因素。方法:复习30例采用CTsim的鼻咽癌患者的治疗计划,将患者所属各组主管医生所勾画的鼻咽原发肿瘤靶区定义为GTV1,笔者同放射科CT诊断室一位主治医师在屏蔽GTV1后共同勾画的GTV定义为GTV2,利用治疗计划系统统计功能分别计算GTV1及GTV2三维轴向的最长径X1、Y1、Z1与X2、Y2、Z2,以及靶区总体积V1、V2,考虑靶区勾画可能存在的随机性误差及扫描层距对肿瘤范围判断的影响,允许GTV1及GTV2在X、Y轴向的最大误差2mm,Z轴向的误差为3mm,采用X1-X2、Y1-Y2、Z1-Z2差值绝对值分别同允许误差进行配对t检验,分析造成GTV1同GTV2差别的原因。结果:GTV1及GTV2在X、Y、Z三维轴向的差别分别为2.95±4.33、6.24±7.52、6.25±9.35(P≤0.001)。GTV1普遍勾画过大,所有病例至少一个部位勾画同GTV2存在差异,差异≥3个部位者达19例,33.33%(10/30)包括过多气腔,33.33%(10/30)在Z轴向上出现靶区勾画不足。结论:不同医生对鼻咽癌GTV的判断存在显著性差异,加强放射治疗科医生影像诊断?BACKGROUND &OBJECTIVE: Accurate delineation of tumor target volu me and organ at risk based on CT simulation, is essential in modern radiotherapy p lanning. It is also the basic requirement to improve the treatment outcome and q uality of life in nasopharyngeal carcinoma (NPC). In this study, the impact fact ors on delineation of the gross tumor volume (GTV) of NPC were analysis. by comp aring difference among various doctorscontours. METHODS: Thirty cases of NPC t reatment planning with contrast enhanced CT scan were reviewed. Primary GTV deli neated by in-charged physician was defined as GTV1. Another GTV delineated by a uthor and a radiologist was defined as GTV2, while GTV1 was concealed by the fun ctions of the treatment planning system, the longest diameters of each axis of G TV were measured and recorded respectively as X1,Y1,Z1,and X2,Y2,Z2. The volumes of GTV were calculated as V1 and V2. Maximum permitted error (MPE) was 2 mm on X and Y axes and 3 mm on Z axis. Margin of each axis was compared to Coparable M PEs by matching t-test. RESULTS: The differences on axes of X, Y, Z between GTV 1 and GTV2 were 2.95±4.33, 6.24±7.52, 6.25±9.35, respectively (P≤0.001). GTV 1 was universally delineated too much, 33.33%(10/30)of them were over contour of air cavity. In all of the cases, at least difference in 1 site was found, wh ile 19 cases had differences in 3 or more sites. However, one third was deficien t on Z axis. CONCLUSION: The delineation of GTV of NPC varied by radiation oncol ogists remarkably. This should be taken into consideration as one of uncertainti es in treatment planning designation. Further training of radiology for radiatio n oncologist to improve their imaging diagnosis ability and implementation of mo re advance imaging equipment are warranted.

关 键 词：鼻咽癌 放射疗法 肿瘤靶区 

分 类 号：R739.63[医药卫生—肿瘤]