双时点18F-FDG PET/CT鉴别胃良恶性病变的价值

目的:评估双时点(dual time point,DTP)18 F-FDG PET/CT在胃良恶性病变的鉴别价值。方法:共纳入106例经病理确诊胃良恶性病变并行DTP 18F-FDG PET/CT患者进行回顾性分析,恶性病变81例,良性病变25例,将胃腺癌病例按照病理结果分为黏液腺癌(mucinous gastric carcinoma,MGC)及非黏液腺癌(non-mucinous gastric carcinoma,non-MGC),比较他们的临床资料、病灶最大厚度（THKmax）、病灶形态、SUVearly、SUVdelayed,计算滞留指数RI(retention index),并绘制ROC曲线得出最佳诊断界值及诊断效能。结果:良性病变的THKmax、SUVearly、SUVdelayed、RI均低于恶性病变,差异具有统计学意义(P<0.05),病灶范围差异无统计学意义(P>0.05)。MGC的SUVearly、SUVdelayed、RI均低于Non-MGC,差异具有统计学意义(P<0.05),THKmax、病灶范围差异无统计学意义(P>0.05)。通过ROC曲线得出鉴别良恶性病变的SUVearly界值为7.95,其灵敏度61.7%,特异度92.0%,准确度67.9%;RI界值为0.229,其灵敏度67.9%,特异度88.0%,准确度71.7%。鉴别MGC与Non-MGC的SUVearly界值为8.65,其灵敏度74.4%,特异度91.7%,准确度80.6%,RI界值为0.228,其灵敏度88.4%，特异度58.3%，准确度77.6%。结论:DTP 18F-FDG PET/CT在胃良恶性疾病的鉴别中具有一定的价值。

The value of dual time point 18F-FDG PET/CT in differentiating benign and malignant gastric lesions

Objective:To evaluate the value of dual time point(DTP)18F-FDG PET/CT in differentiating benign and malignant gastric lesions.Methods:A total of 106 pathologically confirmed benign and malignant gastric lesions with DTP 18F-FDG PET/CT were included for retrospective analysis,81 with malignant lesions and 25 with benign lesions.Gastric adenocarcinoma cases were classified into MGC and Non-MGC according to pathological findings,and SUVearly and SUVdelayed of gastric lesions were measured,Retention Index(RI) was calculated,and ROC curves were plotted to obtain the optimal diagnostic cut-off value and diagnostic efficacy.Results:The THKmax,SUVearly,SUVdelayed and RI of benign gastric lesions were lower than those of malignant gastric lesions,and the differences were statistically significant(P<0.05).There was no significant difference in the range of lesions(P>0.05).The SUVearly,SUVdelayed and RI of MGC were lower than those of Non-MGC,and the differences were statistically significant(P<0.05)，there was no significant difference in the range of lesions and THKmax(P>0.05).The optimal cut-off value of SUVearly for differentiating benign and malignant lesions was 7.95,with a sensitivity of 61.7%,specificity of 92.0%,and accuracy of 67.9%.The optimal cut-off value of RI was 0.229,with a sensitivity of 67.9%,specificity of 88.0%,and accuracy of 71.7%.The SUVearly optimal cut-off value for identifying MGC from Non-MGC was 8.65,which had a sensitivity of 74.4%,specificity of 91.7%,and accuracy of 80.6%,and the RI was 0.228,which had a sensitivity of 88.4%,specificity of 58.3%,and accuracy of 77.6%.Conclusion:DTP 18F-FDG PET/CT has certain value in differentiating benign and malignant gastric lesions.