18F-FDG PET/CT显像定性定量分析对肺癌纵隔淋巴结的诊断价值

摘要

Objective: To discuss the diagnostic value of qualitative and quantitative analysis by 18F-FDG PET/CT for mediastinal lymph nodes of lung cancer Methods: The results of CT, PET and PET/CT imaging scan for 142 patients with space occupying lesions of the lung, who underwent 18F-FDG PET/CT before surgery between April 2005 and October 2009 in Tianjin Medical University Canccr Institute and Hospital were retrospectively analyzed. No anti-tumor treatment was conducted before PET/CT examination in 142 patients. The surgical resection or puncture biopsy was performed a month later. The number of mediastinal node stations was evaluated in nine groups based on the standard of lymph node station of lung cancer by Mountain and Dresler and the AJCC cancer staging manual. The surgical and histological findings served as the reference standard. Chi square test and exact probability were used to compare the diagnostic value of simple CT, the 18F-FDG uptake of the mediastinal lymph node by visual observation, visual observation after consideration of the symmetric distribution and negative calcification, and simple semiquantitative method and the combination of the latter two fbr the whole mediastinal lymph nodes and every station. Results: The stations #2, #4 and #7 were the predilection site of malignant mediastinal lymph nodes, There was a high probability of finding out malignant nodes at # 1, #2, #3 and #8 stations by 18F-FDG PET/CT. Combination of visual observation and semiquantitative method was the best method, especially after considering that calcification and symmetric distribution was benign. The sensitivity, specificity, accuracy and the positive and negative predictive value were 79.2％, 83.8％, 81.9％, 78.5％ and 84.3％ for the detection of the mediastinal lymph node metastases. The accuracy was significantly higher than that of simple CT, visual observation of the 18F-FDG uptake of the lymph nodes, visual observation after considering calcification and symmetric distribution was benign, and simple scmiquantitative method in detcrmining mediasfinal lymph node metastasis (x2=44.678,P=0.000 ). Conclusion: Visual observation is an ideal way of diagnosing the metastasis of the mediastinal lymph nodes of lung cancer, and the SUVmax (the maximum of the standard uptake value) is a useful semiquantitative indicator. The effect of visual observation combining with semiquantitative method is more satisfactory.%目的:探讨18F-FDG PET/CT显像定性、定量分析对肺癌纵隔淋巴结的诊断价值.方法:回顾性分析天津医科大学附属肿瘤医院2005年4月至2009年10月间142例肺部病变患者手术前的CT、PET、PET/CT显像结果.142例患者行PET/CT检查前均未进行抗肿瘤治疗,检查后1个月内行手术或活检取得病理.手术淋巴结分区以1997年美国AJCC为标准.对CT、PET、PET/CT显像结果进行定性及定量分析,观察纵隔淋巴结的分布情况,用卡方检验及确切概率法比较单纯CT、单纯目测纵隔淋巴结摄取程度、考虑对称分布及钙化为阴性后目测法、单纯半定量分析法及定性定量结合对总体及不同分区纵隔淋巴结的诊断效能.结果:2、4、7区是纵隔淋巴结转移的好发部位,1、2、3、8区发现淋巴结则转移的机率高.目测法(尤其在考虑对称分布及钙化因素后)加半定量法诊断效能高(χ2=44.678,P<0.001),其灵敏度79.2%,特异度83.8%,准确率81.9%,阳性预测值78.5%,阴性预测值84.3%.结论:诊断纵隔淋巴结,目测法是较理想方法,SUVmax是很有价值的半定量指标,两者结合效果更佳.