F-FDG PET/CT in the Preoperative Diagnostic and Staging of Lung Cancer and as a Predictor of Lymph Node Involvement.

: The aim of this study was to evaluate the efficacy and accuracy of PET imaging and performance in defining the preoperative TNM classification, especially the intrathoracic lymph node staging, of patients with lung cancer. : A retrospective, single-institution study of consecutive patients with surgical therapy of lung cancer that were undergoing preoperative PET/CT scanning at the same center was conducted. A total of 104 patients were included. All patients underwent surgical evaluation with mediastinal and hilar lymph node sampling. Five patients with preoperative suspicion of N3 nodal status who were only tested for N2 were excluded from the observations and analyses of nodal status. : PET/CT staged the nodal status correctly in 85 out of 99 patients (85.9%); overstaging occurred in 7 patients (7.1%) and understaging in 7 patients (7.1%). The overall prevalence of lymph node metastases was 42.3%. When preoperative T classification was compared with postoperative histopathological T classification, 75% patients were correctly staged, 13.5% were overstaged, and 11.5% were understaged by PET/CT. In univariate analysis, lymph node involvement was significantly associated ( < 0.05) with the following primary tumor characteristics: increasing diameter (>35 mm), a maximum standardized uptake value > 9.5, and higher grading. The tumor diameter and the degree of differentiation were found to be factors influencing the SUV of the primary tumor as well. : Our data show that integrated PET/CT provides high accuracy in the intrathoracic nodal staging and tumor expansion of lung cancer patients and emphasizes the continued need for surgical staging.