^18F—FLT PET／CT显像评估复发脑胶质瘤患者预后的价值

Prognostic value of ^18F-FLT PET/CT imaging in patients with recurrent gliomas

目的 探讨18F-脱氧胸腺嘧啶核苷（FLT） PET/CT显像中的肿瘤增殖体积（PV）在评估复发脑胶质瘤患者预后中的价值.方法 回顾性分析2012年1月至2016年1月行18F-FLT PET/CT与18F-氟脱氧葡萄糖（FDG） PET/CT检查、经病理结果或临床随访证实为复发的20例脑胶质瘤患者的临床资料.在18F-FLT PET/CT图像上测量复发肿瘤的最大标准化摄取值与正常脑组织的平均标准化摄取值的比值（T/NFLT）、最大直径和PV,在18F-FDG PET/CT图像上测量复发肿瘤的T/NFDG.随访时间截至2016年12月.采用Kaplan-Meier分析法进行生存分析,组间比较采用log-rank检验;采用比例风险回归（Cox）模型对PV、最大直径、T/NFDG、T/NLT及其他相关临床因素与预后关系进行单因素和多因素分析.结果 20例复发脑胶质瘤患者的中位生存时间为7个月.PV、T/NFLT、最大直径、T/NFDG、年龄预测长生存期的最佳阈值分别为12.565 cm^3、7.752、2.800 cm、1.192、52岁,对应的ROC曲线下面积（AUC）分别为0.958、0.865、0.745、0.646、0.667.Kaplan-Meier单因素分析结果显示,复发灶不同PV（＜12.565 cm3与≥12.565 cm^3）、T/NFLT（＜7.752与≥7.752）、肿瘤最大直径（＜2.800 cm与≥2.800 cm）、T/NFDG（＜1.192与≥1.192）、首次病理结果（Ⅱ级与Ⅲ、Ⅳ级）间的生存曲线差异均有统计学意义（χ^2 =12.587、12.219、4.285、5.955、6.787,均P＜0.05）.Cox模型单因素分析结果显示,20例复发脑胶质瘤患者的预后与PV、T/NFLT、T/NFDG、首次病理结果有关,危险比分别为0.113（95％CI：0.024～0.530）、0.105（95％CI：0.021～0.513）、0.314（95％CI：0.109～0.903）、0.262（95％CI：0.082～0.838）,差异均有统计学意义（均P＜0.05）.Cox回归模型多因素分析结果显示,肿瘤PV是复发脑胶质瘤患者生存预后的独立影响因素.结论 18F-FLT PET/CT显像中的肿瘤PV可以作为复发脑胶质瘤患者预后的评估指标.

Objectives To evaluate the prognostic value of proliferation volume（PV） measured by pretreating patients with recurrent gliomas with 18F-fluorothymidine （FLT） PET/CT imaging.Methods The clinical data of 20 patients that underwent 18F-FDG PET/CT and 18F-FLT PET/CT examinations from January 2012 to January 2016 showed that recurrent gliomas were retrospectively analyzed.We measured the ratio of the maximum standard uptake value of the tumor to the mean standard uptake value of the normal brain tissue（T/NFLT）,PV,and maximum diameter via 18F-FLT PET/CT imaging,T/NFDG was measured by 18F-FDG PET/CT imaging.The follow-up time lasted until December 2016.Result The median survival time of 20 patients with recurrent gliomas was 7 months.The optimal PV,T/NFLT,diameter,T/NFDG,and age cut-off values were 12.565 cm3,7.752,2.800 cm,1.192,and 52 years,with the area under the curve values of 0.958,0.865,0.745,0.646,and 0.667,respectively.Kaplan-Meier single factor analysis revealed that the survival times significantly differed among patients with different PV（〈12.565 cm3 vs.≥ 12.565 cm3）,T/NFLT （〈7.752 vs.〉7.752）,maximum diameter（〈2.800 cm vs.〉2.800 cm）,and T/NFDG values（〈l.192 vs.〉1.192）,as well as different pathologies of the first operation（WHO Ⅱ vs.WHO Ⅲ and Ⅲ） （χ^2=12.587,12.219,4.285,5.955,6.787;all P〈0.05）.Cox single-factor analyses indicated that PV,T/NFLT,T/NFDG,and pathology were the risk factors of survival,with the hazard ratios of 0.113（95%CI：0.024-0.530）,0.105（95%CI：0.021-0.513）,0.314（95%CI：0.109-0.903）,and 0.262 （95%CI：0.082-0.838）,respectively.Cox multifactor analyses indicated that PV was an independent predictor of survival risk.Conclusion PV is an important factor in the prognosis prediction of patients with recurrent gliomas via 18F-FLT PET/CT imaging.