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

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IGTV_MIP,分别基于PET图像9种不同阈值自动勾画及手动勾画10种IGTV_PET(IGTV_PET2.0、IGTV_PET2.5、IGTV_PET3.0、IGTV_PET3.5、IGTV_PET20%、IGTV_PET25%、IGTV_PET30%、IGTV_PET35%、IGTV_PET40%、IGTV_PETman)。配对t检验比较IGTV_PET与IGTV_MIP靶区位置、体积、包含度及匹配指数差异。 结果 10种 IGTV_PET与IGTV_MIP 中心点坐标仅在z轴差异有统计学意义(P=0.014~ 0.044)。IGTV_{PET2.0 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)。IGTVPET2.0与IGTVMIP 及IGTVPET25%与IGTVMIP 的匹配指数最高,分别为0.46和0.45(P=0.603 )。IGTVMIP 对IGTV PET20% 及IGTVPET2.0 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PETCT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。}

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

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). IGTV_MIP of the primary tumor was delineated on the MIP images of 4DCT. IGTV_PET2.0, IGTV_PET2.5, IGTV_PET3.0, IGTV_PET3.5, IGTV_PET20%, IGTV_PET25%, IGTV_PET30%, IGTV_PET35%, IGTV_PET40% andIGTV_PETmanwere automatically and manually delineated based on different SUV thresholds of FDG PET/CT and different percentages of SUV_max. The differences in position, volume, matching index (MI), and degree of inclusion (DI) between IGTV_PET and IGTV_MIP were evaluated by paired t-test. Results There were significant differences in center coordinate between IGTV_PET and IGTV_MIP only in z axes (P=0.014—0.044). In terms of volume, IGTV_PET2.0 and IGTV_PET20% were most similar to IGTV_MIP, with volume ratios of 1.02 and 1.06(P=0.806). The highest MI was seen between IGTV_MIP and IGTV_PET2.0 and between IGTV_MIP and IGTV_PET20%(0.46 and 0.45, P=0.603). The DI of IGTV_PET20% or IGTV_PET2.0 in IGTV_MIP was the highest (0.61 or 0.61, P=0.963). Conclusions IGTV_PET2.0 and IGTV_PET20% are most similar to IGTV_MIP in terms of volume and matching index, but neither of them could replace IGTV_MIP 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.