Role of integrated F-18 fluoro-deoxy-glucose positron emission tomography and computed tomography in evaluation of lung cancer

Lung cancer is one of the leading causes of death in the world. It is generally divided in two groups: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Positron emission tomography (PET)/CT using the glucose analogue labeled with 18-fluor (F-18): fluoro-deoxy-glucose (F-18-FDG), is unique integrated imaging modality that offers simultaneous anatomic and metabolic information valuable in the diagnosis, staging and follow-up of both types of lung cancer and in particular in NSCLC. FDG accumulation in tissue is proportional to the amount of glucose utilization. Increased consumption of glucose is a characteristic of almost all types of lung cancer except in bronchoalveolar carcinoma and well differentiated neuroendocrine tumors. The objective of this brief review is to highlight the clinical role of F-18-FDG PET/CT in detection, staging, re-staging, and assessment of therapy response and follow up in lung cancer. The performance of F-18-FDG PET/CT in specific clinical situations is of special interest: in the differentiation of indeterminate lung lesions, the staging of NSCLC for lymph node and extra thoracic metastases, for therapy planning, the detection of recurrent lung cancer and the use in SCLC. In conclusion, F-18-FDG PET/CT helps in characterization of suspicious lesions, provides more precise staging of NSCLC than other imaging techniques, allows better patients? selection for new modalities of treatment, helps in restaging after induction therapy, allows better delineation for radiotherapy planning and helps in follow up evaluation by differentiating residual or recurrent tumor from post treatment scar.