^(18)F-FDGPET/CT诊断肝脏单发病灶:患者年龄分层研究

Age-related Diagnostic Performance of ^(18)FDG PET/CT in Differentiation of Malignant and Benign Solitary Lesions in the Liver

目的:在18FDG PET/CT对肝脏单发病灶的诊断中,希望通过患者的年龄分层寻找各年龄层次患者的最佳诊断标准,进而比较年龄分层前后诊断价值的差异。方法:本研究包含272例无肿瘤病史的肝脏单发病灶患者。患者被分为青年组(≤49岁)、中年组(50～69岁)、老年组(≥70岁)。首先,通过ROC曲线分析和AUC的计算,确定总体组及每个年龄组LNR鉴别良恶性病灶的最佳诊断界值和诊断价值及其敏感性和特异性。最后分别比较总体患者组和三个年龄组之间18F-FDG PET/CT对肝脏单发病灶的诊断价值有无统计学差异。结果:通过t检验分析,良恶性组年龄有统计学差异(t=10.23,P≤0.0001)。利用ROC曲线分析、χ2检验及相关分析得出,各年龄组的LNR最佳诊断值分别为:总体组(>1.25),青年组(>1.17),中年组(>1.45),老年组(>1.25)。LNR的AUC分别为:总体组(0.856),青年组(0.962),中年组(0.650),老年组(0.973)。总体组和三个年龄组之间的诊断符合率的比较分别为青年组优于总体组(χ2=13.352,P=0.0003),老年组优于总体组(χ2=8.494,P=0.0036),总体组优于中年组(χ2=9.057,P=0.0026)。结论:不同的年龄组中存在不同的LNR最佳诊断值,年龄分层后,青年组和老年组鉴别肝脏单发病灶良恶性的诊断价值明显优于总体组,总体组明显优于中年组。年龄分层对18FDG PET/CT诊断肝脏单发病灶有重要影响。

Purpose： The purpose of our study was to determine the reliable age stratified diagnostic index in differential diagnosis of malignant and benign solitary lesions in the liver using 18FDG PET/CT. Methods： The enrolled 272 patients with solitary lesions in the liver were divided into three age groups, young group （under 50 years）, middle aged group （50- 69 years）, and old group （over 70 years）. The diagnostic performance and the optimal cut offs of LNR （lesion/normal ratio）were evaluated in terms of malignant and benign lesions in each age group and total patients. And the sensitivity, specificity and accuracy were calculated, on the basis of which the diagnostic accordance rate was compared between each age group and total patients. Results ： T test illustrated that there was a significant age difference between the malignant and benign groups （ t = 3. 905, P = 0. 0001） . ROC（receiver operating characteris tic） analysis showed that the optimal cut off value in all patients, young group, middle - aged group and old group was 1.25, 1.17, 1.45 and 1.25 for LNR, and 0. 856, 0. 962, 0. 650, 0. 973 for AUC（areas under the curves） . The chi - square test proved that diagnostic accordance rate of 18FDG PET/CT in young group and old group were superior to that in all patients（X2 = 13.352, P = 0.0003 and X2 = 8.494 , P = 0.0036）Conversely, the overall diagnostic accordance rate in all patient group was higher than that in middle - aged group （X2 = 9. 057, P = 0. 0026）. Conclusion： The results of our study indicate that diagnostic optimal cut - offs of LNR were different in each age group. In addition, the diagnostic performance of LNR of liver solitary lesions of lSFDG PET/CT in young group and old group were better than that in all patients, and poorer in middle aged group than that in all patients. Therefore, age difference may be one of the important factors for discriminating malignant liver lesions from benign ones using18SFDG PET/CT.