18FDG PET/CT对非小细胞肺癌N2期淋巴结诊断的价值

目的:通过对18FDG PET/CT、CT对非小细胞肺癌N2期纵隔淋巴结的诊断与术后病理结果比较，探讨18FDG PET/CT对N2期淋巴结的诊断价值。方法:72例原发NSCLC患者共切除纵隔N2期淋巴结280枚，回顾性分析术前CT及18FDG PET/CT检查对纵隔N2期淋巴结的诊断结果，并与病理结果分别进行对比分析。结果:175枚N2期淋巴结CT诊断阳性，其诊断的敏感度、特异度、准确度、阳性预测值及阴性预测值分别为:74.0%、50%、62.5%、61.7%及63.8%；而172枚N2期淋巴结18FDG PET/CT诊断阳性，其诊断的敏感度、特异度、准确度、阳性预测值及阴性预测值分别为:89.0%、68.7%、79.3%、75.6%及85.2%，均明显优于CT（P＜0.05）。而105例短径<10 mm的纵隔淋巴结中，36.2%（38/105）为转移淋巴结，18FDG PET/CT对CT诊断阴性的纵隔淋巴结的诊断敏感度、特异度、准确度、阳性及阴性预测值分别为:86.8%、88.1%、87.6%、80.5%及92.2%；其中高代谢的N2期小淋巴结主要分布于2R、4R/L、7组:36.4%（12/33）、27.3%（9/33）、36.4%（12/33）。结论:18FDG PET/CT对肺癌N2期纵隔淋巴结的诊断价值明显优于CT，尤其对于纵隔内短径<10 mm淋巴结转移的诊断具有明显优势。

The differential value of 18FDG PET/CT to N2 mediastinal lymph nodes in NSCLC

Objective:To evaluate the diagnostic value of 18FDG PET/CT in assessing the involvement of central mediastinal lymph nodes (N2) in NSCLC.Methods:Seventy-two NSCLC patients with 280 stations of mediastinal lymph nodes were dissected.We respectively analyzed the diagnosis of N2 lymph nodes by preoperative CT and 18FDG PET/CT with pathological diagnosis.Results:One-hundred seventy-five stations of N2 lymph nodes were diagnosed metastasis by CT and 172 stations by 18FDG PET/CT scan.The sensitivity,specificity,accuracy,positive and negative predictive value of CT and PET/CT were 74.0% vs 89.0%,50% vs 68.7%,62.5% vs 79.3%,61.7% vs 75.6% and 63.8% vs 85.2%,respectively.PET/CT scan showed significantly higher diagnosis performance than CT scan (P＜0.05).Of 105 recorded <10 mm N2 lymph nodes 36.2%(38/105) was positive by pathology,and the sensitivity,specificity,accuracy,positive and negative predictive value by 18FDG PET/CT scan were 86.8%,88.1%,87.6%,80.5% and 92.2%,respectively.While,the high 18FDG uptake of <10 mm N2 lymph nodes were located to stations 2R,4R/L and 7,which were 36.4%(12/33),27.3%(9/33) and 36.4%(12/33),respectively.Conclusion:18FDG PET/CT scan is more sensitive and accurate than CT in diagnosis of N2 lymph nodes,especially for evaluation of <10 mm mediastinal lymph nodes.