[Positron emission tomography in the evaluation of intrathoracic lymphatic extension of non-small cell bronchial cancer. A preliminary study of 30 patients].

Current methods for evaluating the mediastinum include chest radiography, computed tomography (CT) or magnetic resonance (MR) imaging and mediastinoscopy. Despite advances in morphologic imaging, some lung cancer patients are found to have unresectable disease at surgery. In contrast to CT scan or MR imaging, which depend primarily on anatomic and morphological criteria, positron emission tomography (PET) with 18fluorodeoxyglucose (FDG) depends mainly of the metabolic characteristics of a tissue for the diagnosis of disease. We perform a prospective study to compare FDG-PET and CT of the thorax in the presurgical assessment of the mediastinum in patients with newly diagnosed non-small cell lung cancer. Thirty patients have been included. CT and PET-scans were interpreted separately and results were compared to surgical staging during thoracotomy. In assessing mediastinal involvement, CT scan had a sensitivity of 56% and a specificity of 64%. For diagnosis mediastinal nodal disease, FDG-PET was 87% sensitive and 78% specific. Its positive predictive value was 82%, and the negative value was 83%. In conclusion, our preliminary results show that FDG-PET appears more accurate than CT in staging of mediastinal non-small cell lung cancer.