ABSTRACT
OBJECTIVES: In this study, we aimed to define the efficacy of F-18 FDG PET/CT for the detection of mediastinal lymph node metastases by comparing the mediastinal findings of F-18 FDG PET/CT with the histopathological results obtained either by mediastinoscopy or thoracotomy in patients with clinically operable non-small cell lung cancer (NSCLC). MATERIAL AND METHODS: This is a prospective, single-institution study of 68 consecutive patients with suspected or pathologically proven, localized, clinically resectable NSCLC (8 females and 60 males; mean age: 60.36 ± 1.01 years, range: 43-78 years). The patients underwent integrated PET/CT scanning at the same PET center. Standard cervical mediastinoscopy and extended mediastinoscopy were performed to sample the lymph nodes. During thoracotomy, complete mediastinal lymph node dissection was routinely performed. RESULTS: Mediastinoscopy gave true positive results in 9 patients and true negative results in 57 patients. There were two false negative results. Mediastinoscopy had a sensitivity of 81.8% (95% CI: 63-82), a specificity of 100% (95% CI: 96-100), a PPV of 100% (95% CI: 77-100), a NPV of 96.6% (95% CI: 93-96), and an accuracy of 97% for the detection of mediastinal lymph node metastases. When PET/CT results were compared with postoperative pathological examination results, PET/CT correctly identified 48 out of 50 patients (96%) who did not have metastatic lymph node involvement. N2/N3 disease was correctly determined by PET/CT in 8 of 11 patients (72.7%) who had positive results on histological analysis. When only N2 and N3 nodal diseases were included in the calculation with the aim of making a comparison with mediastinoscopy (for mediastinal nodes), integrated PET/CT had a sensitivity of 72.7% (95% CI: 51-80), a specificity of 97.7% (95% CI: 92-99), a PPV of 88.9% (95% CI: 62-97), a NPV of 93.3% (95% CI: 88-95) and an accuracy of 92.6% (95% 83-95) for the detection of intrathoracic N2 and N3 nodal metastases. CONCLUSION: Our data shows that due to its high sensitivity and accuracy, mediastinoscopy is still the most reliable method to evaluate mediastinal lymph nodes in patients with NSCLC.
