[^18F] Fluorodeoxyglucose (FDG) is a radiopharmaceutical used in positron emission tomography (PET) imaging. It is an analog of glucose, where the hydroxyl group on the 2′ carbon is replaced by the positron-emitting radionuclide fluorine-18 ([^18F]). The chemical structure allows FDG to mimic glucose in the body, making it an effective tracer for metabolic activity.
Once injected into the body, FDG is transported into cells via glucose transporters and phosphorylated by hexokinase to FDG-6-phosphate. Unlike glucose-6-phosphate, FDG-6-phosphate cannot undergo further glycolysis and becomes trapped within the cell. The accumulation of FDG in tissues is proportional to the rate of glucose uptake and phosphorylation, reflecting cellular metabolic activity.
FDG-PET is widely used in oncology, cardiology, and neurology due to its ability to highlight areas of increased glucose metabolism. Here are the detailed applications in different medical fields:
Differentiates viable myocardium from scar tissue in patients with ischemic heart disease. Viable myocardium will take up FDG, indicating metabolic activity, whereas scar tissue will not.