LYMPH-NODE STAGING IN NONSMALL CELL LUNG-CANCER - EVALUATION BY [F-18] FDG POSITRON EMISSION TOMOGRAPHY (PET)

Background - A study was undertaken to investigate the accuracy of pos itron emission tomography (PET) with 2-[F-18]-fluoro-2-deoxy-D-glucose (FDG) in the thoracic lymph node staging of non-small cell. lung canc er (NSCLC). Methods - Forty six patients with focal pulmonary tumours who underwent preoperative computed tomographic (CT) and FDG-PET scann ing were evaluated retrospectively. Thirty two patients had NSCLC and 14 patients had a benign process. The final diagnosis was established by means of histopathological examination at thoracotomy, and the noda l classification in patients with lung cancer was performed by thoroug h dissection of the mediastinal nodes at surgery. Results - FDG-PET wa s 80% sensitive, 100% specific, and 87.5% accurate in staging thoracic lymph nodes in patients with NSCLC, whereas CT scanning was 50% sensi tive, 75% specific, and 59.3% accurate. The absence of lymph node tumo ur involvement was identified by FDG-PET in all 12 patients with NO di sease compared with nine by CT scanning. Lymph node metastases were co rrectly detected by FDG-PET in three of five patients with N1 disease compared with two by CT scanning, in nine of 11 with N2 disease compar ed with six by CT scanning, and in all four with N3 nodes compared wit h two by CT scanning. Conclusions - FDG-PET provides a new and effecti ve method for staging thoracic lymph nodes in patients with lung cance r and is superior to CT scanning in the assessment of hilar and medias tinal nodal metastases. With regard to resectability, FDG-PET could di fferentiate reliably between patients with N1/N2 disease and those wit h unresectable N3 disease.