MRI/CT影像融合对鼻咽癌靶区勾画的影响  

Influence of CT-MRI fusion image on definition of the target volumes of nasopharyngeal carcinoma

作　　者：陈建武[1] 潘建基[2] 柏鹏刚[2] 郑威[2] 张春[2] 陈韵彬[2] 蔡述华[2] 林少俊[2] 吴君心[2] 

机构地区：[1]福建医科大学附属第二医院放疗科,泉州362000 [2]福建医科大学教学医院/福建省肿瘤医院放疗科,福州350014

出　　处：《肿瘤》2009年第1期61-64,共4页Tumor

摘　　要：目的:探讨MRI/CT影像融合对鼻咽癌靶区勾画的价值。方法:本院2006年2月—5月接受调强三维适形放疗(intensity modulated radiotherapy,IMRT)治疗的初诊鼻咽癌患者6例,CT及MRI扫描后行MRI/CT影像融合,由3位经验丰富的高年资放疗科医师(命名为医师1、2、3)勾画鼻咽部肿瘤靶区(grosstumor volume,GTV),每位医生针对CT图像(参照MRI片)及MRI/CT融合图像先后各勾画1个GTV,共生成18个CT图像的GTV(CT靶区)及18个MRI/CT融合图像的GTV(MRI靶区),研究影像融合对靶区勾画的影响。结果:CT靶区的平均体积为51.4cm3,大于MRI靶区的43.4cm3,大多数(66.7%)MRI靶区比CT靶区小,2种靶区在三维空间各个方向上都有差异。不同观察者所勾画的靶区有一定的差异,他们之间所勾画的CT靶区最大与最小的差异为12cm3,而MRI靶区最大与最小之间差异为7cm3,而且医师1与3之间以及2与3之间在靶区勾画上的差异有统计学意义(配对t检验P分别为0.002及0.006)。由于主观认识上的差异,不同医师根据MRI/CT融合图像勾画的靶区(MRI靶区)之间的差异小于根据CT图像勾画的靶区(CT靶区)之间的差异(t检验,P=0.000)。结论:MRI/CT影像融合影响鼻咽癌靶区的勾画,不同医师勾画的靶区常因主观认识上的差别而存在一定的差异,MRI/CT影像融合可以缩小医师之间靶区勾画的差异。Objective ： To discuss the values of MRI-CT fusion image for definition of the target volumes of nasopharyngeal carcinoma （NPC）. Methods ： CT simulation and MRI scans were obtained for 6 NPC patients who received three-dimensional conformal RT （3-DCRT） in our hospital between February and May 2006. The images of CT and MR were fused. The gross tumor volume （GTV） of NPC was defined independently by 3 experienced radiologists （called doctor 1, 2, and 3 ）. Every doctor delineated one GTV on CT images and one GTV on MRI-CT fused images. Totally 18 CT-based GTV were determined and 18 MRI-CT-based GTV were deter- mined. Influences of CT-MRI fusion image for definition of the target volumes were analyzed. Results： The mean CT-based target volume was 51.4 cm3 , being bigger than that of MRI-based target volume （43.4 cm3 ）. Most of the MRI-based target volume （66.7%） was smaller than CT-based target volume. The two types of target volume had a significant difference in every 3-D direction. There existed some variations among the definition results given by the 3 radiologists. The biggest discrepancy was 12 cm3 in definition of CT-based target volume and 7 cm3 in definition of MRI-based target volume. The difference between doctor 1 and 3 or between doctor 2 and 3 was significant （paired t test; P = 0. 002 and 0.006, respectively）. Because of the different cognitive abilities of radiologists, the difference in MRI/CT-based target volume between the doctors was smaller than that based on CT images （ paired t test ; P = 0. 000）. Conclu- sion：MRI-CT fusion image had an influence on tumor volume definition of nasopharyngeal carcinoma. There existed some variations in cognitive abilities of radiologists. MRI-CT fusion image decreased the variation in target volume determination between different radiologists.

关 键 词：鼻咽肿瘤 诊断显像 放射疗法 

分 类 号：R739.6[医药卫生—肿瘤] R730.55[医药卫生—临床医学]