摘要Background This retrospective study evaluated the diagnostic accuracy of 2-(F18)-fluoro-2-deoxy-D-glucose-positron emission tomography(18F-FDG-PET)/COmputed tomography(PET/CT)in the preoperative diagnosis of metastatic mediastinal and hilar lymph node in patients with non-small-cell lung cancer(NSCLC).Methods A total of 39 patients received preoperative 18F-FDG PET/CT and the postoperative biopsy.We compared preoperative PET/CT scan results with corresponding intraoperative histopathalogic findings in 39 NSCLC patients.The sensitivity,specificity,accuracy,positive and negative predictive value of 18F-FDG PET/CT were assessed.Results Histopathologic examination confirmed metastasis in 57 out of the 208 excised lymph nodes;23 of the 57 nodes were mediastinal and hilar lymph nodes.The sensitivity,specificity,accuracy,positive predictive value and negative predictive value of PET/CT in the preoperative diagnosis of mediastinal lymph node metastasis in NSCLC patients were 65%,96.8%,92%,78.5%and 90%,respectively.Conclusions PET/CT scan showed good accuracy in the preoperative diagnosis of mediastinal and hilar lymph node metastasis in the patients with NSCLC.We recommend that PET/CT scanning be used as a first-line evaluation tool for tumor diagnosis,therapy evaluation and follow-up.