4DCT MIP图像与FDG PET-CT不同SUV阈值勾画NSCLC IGTV的比较研究

Comparison of internal gross tumor volumes delineated based on MIP images of 4DCT and different SUN thresholds of FDG PET/CT for non-small cell lung cancer

目的 比较NSCLC基于4DCT MIP图像与FDG PET-CT不同SUV阈值勾画所得靶区间体积及位置差异.方法 10例NSCLC患者序贯完成胸部3DCT、4DCT增强扫描并基于相同体位固定方式及定位参数行FDG PET-CT扫描.在4DCT MIP图像上勾画IGTVMIP,分别基于PET图像9种不同阈值自动勾画及手动勾画10种IGTVPET（IGTVPET2.0、IGTVPET2.5、IGTⅣPET3.0、IGTVPET3.5、IGTVPET20％、IGTVPET25％、IGTVPET30％、IGTV PET35％、IGTVPET40％、IGTVPETman）.配对￡检验比较IGTVPET与IGTVMIP靶区位置、体积、包含度及匹配指数差异.结果 10种IGTVPET与IGTVMIP中心点坐标仅在z轴差异有统计学意义（P=0.014 ～0.044）.IGTVPET2.0及IGTVPET20％与IGTVMIP体积大小最接近,体积比分别为1.02和1.06（P =0.806）.IGTV PEET2.0与IGTVMIP及IGTVPET20％与IGTVMIP的匹配指数最高,分别为0.46和0.45（P =0.603）.IGTVMIP对IGTVPET20％及IGTVPET20的包含度最高,分别为0.61和0.61 （P =0.963）.结论 基于PET SUV值2.0及最大值的20％勾画的IGTVPET与基于4DCT MIP图像构建的IGTVMIP体积大小最接近、空间错位也相对较少,但就空间位置而言,两者均不能替代IGTVMIP.基于PET-CT勾画NSCLC原发肿瘤靶区时,选择合适的SUV值的同时要参照4DCT进行靶区位置校正.

Objective To compare the positional and volumetric differences between internal gross target volumes （IGTV） based on the maximum intensity projection （MIP） images of four-dimensional computed tomography （4DCT） and different standardized uptake value （SUV） thresholds of fluorodeoxyglucose （FDG） positron emission tomography/CT （PET/CT） for the primary tumor of non-small cell lung cancer （NSCLC）.Methods Ten patients with NSCLC sequentially underwent contrast-enhanced 3DCT and 4DCT,as well as FDG PET-CT （with the same body position and positional parameters）.IGTVMIP of the primary tumor was delineated on the MIP images of 4DCT.IGTVPET2.0,IGTVPET25,IGTVPET3.0,IGTVPET3.5,IGTVPET20％,IGTVPET25％,IGTVPET30％,IGTVPET35％,IGTVPET40％ and IGTVPETman were automatically and manually delineated based on different SUV thresholds of FDG PET/CT and different percentages of SUVmax.The differences in position,volume,matching index （MI）,and degree of inclusion （DI） between IGTVPET and IGTVMIP were evaluated by paired t-test.Results There were significant differences in center coordinate between IGTVPET and IGTVMIP only in z axes （P =0.014-0.044）.In terms of volume,IGTVPET2.0 and IGTVPET20％ were most similar to IGTNMIP,with volume ratios of 1.02 and 1.06（P =0.806）.The highest MI was seen between IGTVMIP and IGTVPET2.0 and between IGTVMIP and IGTVPET20％ （0.46 and 0.45,P =0.603）.The DI of IGTVPET20％ or IGTVPET2.0 in IGTVMIP was the highest （0.61 or 0.61,P =0.963）.Conclusions IGTVPET20 and IGTVPET20％ are most similar to IGTVMIP in terms of volume and matching index,but neither of them could replace IGTVMIP in spatial position.When the IGTV of the primary tumor of NSCLC is delineated based on PET-CT,target position correction should be done with reference to 4DCT images while selecting the suitable SUV threshold.