Fluorodeoxyglucose F-18 (FDG)
Also known as: FDG, 18F-FDG, fludeoxyglucose F 18, PET tracer
The radioactive sugar used in most PET scans: cells that use a lot of glucose, such as many cancers, take it up and light up on the image.
- Generic name
- Fluorodeoxyglucose F-18 (FDG)
- Active ingredient
- Fluorodeoxyglucose F-18 (FDG) (variants: fludeoxyglucose (18F))
- Product type
- Radiopharmaceutical
- Drug class
- Diagnostic radiopharmaceuticals
- Brand names
- No brand names recorded; supplied as the generic medicine
- Routes
- Intravenous (Intravenous injection about an hour before the scan)
- Dosage forms
- Injection
- Also known as
- FDG, 18F-FDG, fludeoxyglucose F 18, PET tracer
- Forms
- Injection prepared on the day in a radiopharmacy and given by the nuclear medicine team
- Onset and duration
- Taken up over 45-60 minutes before imaging; radioactivity halves every 110 minutes and is largely gone within a day.
- Terminology
- ATC V09IX04
- Monitoring
- Blood glucose before the injection; radiation-safety advice for the hours after the scan; no follow-up tests for the tracer itself.
Availability by country
| Country | Status | Note | Source |
|---|---|---|---|
| UK | Hospital only | Prepared in a licensed radiopharmacy and administered in nuclear medicine departments | UK |
Legal status differs between countries and can change; each row cites the document it was taken from and applies only to the country named.
What it is used for
- Staging cancer, assessing response to treatment and looking for recurrence
- Finding the source of inflammation or infection, including fever of unknown cause
- Assessing brain metabolism in dementia and epilepsy
- Assessing whether heart muscle is still alive after a heart attack
How it works in the body
FDG is glucose with a positron-emitting fluorine atom in place of one hydroxyl group. Cells take it up through their glucose transporters and phosphorylate it, but cannot metabolise it further, so it is trapped in proportion to how much glucose the tissue is using. When the fluorine decays, each positron meets an electron and produces two gamma rays travelling in opposite directions; the PET scanner detects the pairs and reconstructs where the tracer accumulated, usually fused with a CT scan for anatomy.
Common side effects
- Usually none from the tracer itself; a small radiation dose
Serious: seek help
- Rare allergic-type reactions
Cautions and interactions
- Fasting for several hours and avoiding strenuous exercise before the scan, because glucose and active muscle compete with the tracer
- Blood glucose is checked beforehand; high glucose or a recent insulin dose reduces tumour uptake
- Pregnancy and breastfeeding are declared before the injection
- Diabetes needs planning of medicines and timing with the department
Interactions
Check interactions
Taking Fluorodeoxyglucose F-18 (FDG) with other medicines? Add them to the checker to see what the official sources say about each pair: the mechanism, general management and monitoring, never a bare "safe".
Interactions documented in the official sources cited on each card. The list covers the medicines represented on this site and is not exhaustive; how the interaction data is compiled.
No pair records for this medicine are in the sources currently represented by Anatomy Nexus. Absence from this list does not mean no interaction exists.
Radiopharmaceutical profile
- Isotope
- Fluorine-18 (positron emitter, half-life about 110 minutes)
- Targeting mechanism
- Taken up by glucose transporters and trapped inside cells after phosphorylation, so it accumulates where glucose use is high: many tumours, inflammation, the brain and the heart
- Use
- Diagnostic (imaging)
- Related imaging
- PET-CT scan, CT scan
Same-class and related medicines
Same class: Diagnostic radiopharmaceuticals
Medicines that share the class of Fluorodeoxyglucose F-18 (FDG). They are separate medicines with their own licences, doses and interactions, not alternative names for Fluorodeoxyglucose F-18 (FDG).
Related medicines
Medicines often discussed alongside Fluorodeoxyglucose F-18 (FDG): used together, compared with it, or acting on the same problem by a different route.