Staging of non-small cell lung cancer.: Diagnosis efficacy of structural (CT) and functional (FDG-PET) imaging methods

Purpose. To evaluate diagnostic accuracy of FDG-PET in the definition of non-small cell lung cancer (NSCLC) and analyze diagnostic validity of CT scan and FDG-PET in its staging. Methods. Patients with clinical suspicion of potentially resectable NSCLC (n = 108) were studied by standard procedures in our setting, including fibrobronchoscopy, transthoracic fine-needle aspiration, thoracoabdominal CT scan and FDG-PET. Gold standard was histopathological study in patients who underwent surgery and by specific imaging methods and biopsy, when available, in patients who did not. Results. In 13% of patients, the FDG-PET findings were negative and no tumor was observed in the histological study of the piece. In 22% of patients, FDG-PET detected metastatic disease (MO by CT scan). For mediastinal involvement, global diagnostic accuracy was 0.90 with FDG-PET and 0.59 with CT scan. False positive FDG-PET findings were produced by inflammatory conditions and false negative findings by the small size or proximity of lymph nodes to primary tumor. Mediastinal staging by CT scan and FDG-PET was correct in 56% and 87% of patients, respectively. Conclusions. Although complementary, the functional method (FDG-PET) is significantly superior to the structural method (CT) for detection of mediastinal tumor disease.