OVERVIEW

[^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.

Mechanism of Action

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.

Applications in Medical Imaging

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:

ONCOLOGY

Diagnosis

Staging

Monitoring therapeutic response

Detection in case of reasonable suspicion of recurrences

CARDIOLOGY

Myocardial Viability:

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.

NEUROLOGY

Epilepsy:

Dementia: