鼻咽癌螺旋断层治疗计划中静脉注射造影剂对剂量计算的影响  

Research on influence of intravenous contrast agent on dose calculations of helical tomotherapy plans for nasopharyngeal carcinoma

作　　者：解传滨[1] 徐寿平[1] 戴相昆[1] 王小深[1] 丛小虎[1] 巩汉顺[1] 葛瑞刚[1] 鞠忠建[1] 

机构地区：[1]解放军总医院放射治疗科,北京100853

出　　处：《中国医学装备》2016年第1期84-87,共4页China Medical Equipment

摘　　要：目的:探讨鼻咽癌(NPC)螺旋断层治疗(HT)中静脉注射造影剂所致CT值变化对剂量计算的影响,并评价其临床意义。方法:回顾性选取10例已行CT平扫(C-)+增强(C+)并接受HT的NPC患者资料,在计划验证模块用C+图像替代C-图像实施剂量再计算,选取靶区及各兴趣器官内10点读取原计划和验证计划CT值和点剂量行对比分析。结果:C-与C+靶区剂量偏差为0.31%,各兴趣器官中血管差别最大为1.13%。腮腺剂量差为0.55%。脑干差别最小,剂量差为0.39%。结论:在C-与C+条件下HT计划剂量计算差别较小,理论上可直接在增强CT图像上行计划优化,但考虑血管等CT值变化较大,对每次治疗前X射线计算机体层摄影术(MVCT)自动灰度配准会产生一定影响可能,故在临床运用中需谨慎。Objective： To investigate the influence of computed tomography（CT） values increased by intravenous contrast agent（CA） on dose calculations of Helical Tomotherapy（HT） plans for nasopharyngeal carcinoma（NPC）. Methods： Eight patients with NPC treated by HT were enrolled. Eah patient took two sets of CT in the same position before and after intravenous CA injections. Dose recalculations were done using the C＋ images which were uses as a substitute for the C- images of original plans in the QA mode. The 10 points were selected randomly from every target and organ of interest, the CT values and the point doses of the QA plans were compared with the original plans in the same coordinate system. Results： The dose deviation of targets in C- and C＋ plans was 0.31%, The vessels indicated the highest difference（1.13%）, the dose difference of parotids was 0.55%, the difference of brainstem was the smallest with 0.39%. Conclution： The influence of intravenous contrast agent on dose calculations of HT plans for NPC is small. The C＋ images can be used in HT planning theoretically. But the CT values of some tissues such as vessels were increased significantly, which may lead to the errors on the automatic registration of MVCT before delivery. So it needs to be careful in clinical use.

关 键 词：鼻咽癌 螺旋断层治疗 造影剂 剂量计算 电子计算机断层扫描 

分 类 号：R739.62[医药卫生—肿瘤]