CT模拟定位中扫描层厚对肿瘤靶区体积的影响  

The Effect of CT Scans Slice Thickness on Gross Target Volume in CT Simulation

作　　者：姚原[1] 吴国华[1] 吴旭东[1] 曹鑫强[1] 蒋马伟[1] 沈维生[1] 

机构地区：[1]上海第二医科大学附属新华医院肿瘤放疗科,200092

出　　处：《实用癌症杂志》2001年第4期410-412,共3页The Practical Journal of Cancer

摘　　要：目的　研究CT扫描层厚对肿瘤靶区体积 (GTV )的影响。方法　在PQS CT模拟定位机上 ,应用层厚分别为 2mm、3mm、5mm、10mm的条件 ,分别对埋入同一蜡块中的 3个不同直径的物体进行扫描 ,然后在ACQSIM (虚拟模拟工作站 )上逐层画出物体的外轮廓 ,最后利用工作站的统计功能计算出 3个被测物体的前后径、左右径、上下径和体积。结果　被测物体前后径、左右径在CT影像所测数值与实际测量数值的误差在 0 .5mm以内 ,而上下径的CT数值与实际测量数值的误差大都在 1mm以上 ,被测物体体积和物体上下径的误差与扫描层厚呈正比例关系。结论　临床医生在确定临床靶区体积 (CTV )的上下径时 ,需要考虑GTV的上下径约有 75 %± 61%扫描层厚厚度的范围是不确定的。扫描层厚越薄 ,扫描得到的肿瘤体积越接近实际的肿瘤体积。Objective To study the effect of CT scan slice thickness on Gross Target Volume(GTV).Methods Three differ diameter objects,buried in a piece of max were scanned with PQS CT simulator(made by Picker international Inc),the scan slice thickness was:2 mm;3 mm;5 mm;10 mm respectively.After that the slice of three objects on the CT images were contoured one by one with ACQSIM(virtual simulation workstation).Finally the fore-back caliber;right-left caliber;up-down caliber and volume of three objects were calculated by the statistic function of the workstation.Results It was no more than 0.5 mm that the errors of the fore-back caliber and right-left caliber of three objects measured by the CT images compared with reality.Moreover,it was more than 1mm that the errors of the up-down caliber of three objects measured by the CT images.The errors of the object′s volume and the up-down caliber had direct ratio with the scan slice thickness.Conclusion When physicians want to define clinical target volume(CTV),it should be considered that the up-down caliber of GTV has a bound of 75%±61% of the scan slice thickness which is uncertain.If the scan slice thickness is thinner,the GTV on the CT images is more approached to the reality.

关 键 词：CT模拟定位 扫描层厚 肿瘤靶区体积 

分 类 号：R730.44[医药卫生—肿瘤]