This clinical lecture demonstrates the current and future role of 18-F FDG PET/CT in the diagnosis of NSCLC (non-small cell lung cancer) (usefulness/limitations) and prognosis in lung cancer treatment. PET-CT combines metabolic and morphological data, which makes it possible to offer better possibilities for diagnosing malignant pulmonary nodules compared to conventional CT. Integrated PET-CT combines the advantages of PET and CT, minimizing their limitations in the diagnosis, staging and treatment of NSCLC. PET-CT offers a better assessment of lymph node involvement and the presence of local or distant metastatic disease than can be done with conventional imaging alone, and is often used to interpret suspicious lesions detected by such imaging techniques.