Positron Emission Tomography (PET): Clinical Applications in Oncology

Positron Emission Tomography (PET) is a functional diagnostic imaging technique which can accurately measure in vivo distribution of a radiopharmaceutical with high resolution. The ability of PET to study various biological processes opens up new possibilities for both research and clinical use. PET has progressed rapidly from being a research technique in laboratories to a routine clinical imaging modality becoming the part of armamentarium of medical profession. The most widely used radiotracer in PET is Florine18-fluorodeoxyglucose (F18-FDG), which is an analogue of glucose. The FDG uptake in cells is directly proportional to glucose metabolism of cells. Since glucose metabolism is increased many-fold in malignant tumors, PET has a high sensitivity and a high negative predictive value. PET with FDG is now the standard of care in initial staging, monitoring the response to the therapy, and management of lung cancer, colonic cancer, lymphoma, melanoma, esophageal cancer, head and neck cancer and breast cancer. In addition, PET has also played an important role for both diagnosis and therapy planning in seizures, dementia, ischemic heart diseases, infections and inflammations, vasculitis and other autoimmune diseases. The aim of this review article is to review the clinical applications of PET.