F-18 fluorodeoxyglucose (FDG) is the most common PET radiotracer.
The radiopharmaceutical consists of the fluorine-18 radionuclide substituting the hydroxyl group at the C-2 position of glucose. The IUPAC chemical name is 2-deoxy-2-[F-18]fluoroglucose.
F-18 fluoride ion is created in a cyclotron and then converted via an automated chemistry module into F-18 FDG. Specifically, F-18 FDG is produced through a nucleophilic substitution reaction, using the F-18 fluoride by nuclear reaction O (p,n) F starting from water (H2O) enriched with oxygen-18.
- physical half-life: 110 minutes
- excretion: renal
Physiologic activity is commonly seen in the following organs:
- heart (especially left ventricular myocardium)
- kidneys and bladder (due to urinary excretion)
- liver (often used as an internal reference standard on whole body scans)
Other sites of physiologic uptake are variable or less intense:
- skeletal muscle (in extremities after strenuous activity, in mouth and larynx after speech or chewing)
- brown fat (especially in the neck and mediastinum)
- gastrointestinal mucosa
- hematopoietic/lymphoid tissue: Waldeyer ring, thymus, spleen, and bone marrow
- salivary glands
- lactating breasts
- whole body
- cancer staging and surveillance
- evaluation of patients with fever of unknown origin
- identification of viable and ischemic myocardium