^(18)F-FLT PET/CT与MRI在脑胶质瘤放射治疗靶区勾画中的比较研究

Comparative study of ^(18)F-FLT PET/CT and MRI in delineation of targets for radiotherapy of glioma

目的通过对脑胶质瘤术后患者在放疗前分别进行MRI、^(18)F-FLT PET/CT显像,探讨在CT图像上分别联合上述两种显像方式进行靶区勾画,观察其对胶质瘤靶区勾画及放疗计划的影响。方法对14例脑胶质瘤术后经MRI检查认为存在术后残留的患者进行^(18)F-FLT PET/CT显像检查,对所有患者分别在增强CT图像与^(18)F-FLT PET/CT或MRI融合显像上进行靶区勾画,之后应用计划系统进行2组影像的靶区比较。结果在MRI和^(18)F-FLT PET/CT上勾画出的靶区体积差异有统计学意义(Z=3.545,P<0.05),GTV和CTV均为PET/CT高于MRI,GTV PET比GTV MR平均增大2.53 cm^(3),CTV PET比CTV MR平均增大6.79 cm^(3)。不同医师之间在MRI及PET/CT上勾画的GTV差异均无统计学意义(χ^(2)=0.143,P>0.05);不同医师在MRI上勾画的GTV与在PET/CT上勾画的GTV最大值与最小值之间差异无统计学意义(Z=0.785,P>0.05),PET/CT组的GTV离散程度为5.69 cm^(3),MRI组GTV离散程度为7.86 cm^(3)。在MRI和PET-CT上勾画GTV、CTV的靶区重合度差异有统计学意义(TC GTV=0.642±0.071,t=33.763,P<0.05;TC CTV=0.709±0.067,t=39.622,P<0.05)。结论以MRI和^(18)F-FLT PET/CT为辅助影像勾画出的靶区体积及重合度存在差异性,二者显示的肿瘤范围不同;不同勾画者在MRI及PET/CT上勾画的GTV及CTV体积无差异性,但PET/CT组的GTV离散度较MRI组小,说明不同医师在^(18)F-FLT PET/CT上勾画的靶区范围认知差异度小。

Objective To investigate the effects of MRI and^(18)F-FLT PET/CT imaging on the patients of glioma surgery before radiotherapy,To explored the combination of the above two imaging methods to delineate the target area on the CT image,and observe its target for glioma district delineation and the impact of radiotherapy plans.Methods^(18)F-FLT PET/CT imaging was performed in 14 patients with gliomas who were considered to have postoperative residuals by MRI examination.All 14 patients were fused with^(18)F-FLT PET/CT or MRI with enhanced CT images.The target area was delineated on the imaging,and then the planning system was used to compare the target area of the two groups of images.Results There was a difference in target volume between MRI and^(18)F-FLT PET/CT(Z=3.545,P<0.05).GTV and CTV were higher in PET/CT than MRI,GTV PET increased by 2.53 cm^(3)on average than GTV MR.CTV PET increased by 6.79cm^(3)on average than CTV MR.There was no difference in GTV delineated on MRI and PET/CT between different physicians(P>0.05);the difference between the maximum and minimum GTV delineated on MRI by different physicians and the maximum and minimum GTV delineated on PET/CT was not statistically significant(P>0.05);the dispersion of GTV in the PET/CT group was 5.69 cm^(3),the dispersion of GTV in the MRI group was 7.86 cm^(3).There was a difference in the coincidence of the target areas of GTV and CTV on MRI and PET-CT(P<0.05).Conclusion There are differences in the volume and coincidence of the target area delineated by MRI and^(18)F-FLT PET/CT,and the tumor range displayed by the two is different.There is no difference in the volume of GTV and CTV delineated on MRI and PET/CT by different delineators,but the GTV dispersion in the PET/CT group was smaller than that in the MRI group,indicating that the different physicians have less cognitive differences in the range of targets outlined on^(18)F-FLT PET/CT.