How PET-CT Works
A small amount of radioactive tracer is injected; cancer cells that take up more tracer glow on the PET image, while CT adds anatomical detail. The combined scan shows both where and how active a tumor is.
Common Tracers
| Tracer | Used for |
|---|---|
| FDG | Most cancers — lymphoma, lung, melanoma, head & neck |
| PSMA (Ga-68 / F-18) | Prostate cancer staging and recurrence |
| DOTATATE | Neuroendocrine tumors |
| Fluoroestradiol (FES) | ER-positive breast cancer |
Preparing for Your Scan
- Fast for 4–6 hours for FDG scans
- Tell staff if you are diabetic, pregnant or breastfeeding
- Avoid strenuous exercise the day before
- Plan for 2–3 hours at the imaging center
Theranostics
The same targets used for imaging can deliver radiation therapy — for example Lu-177 PSMA therapy for prostate cancer and Lu-177 DOTATATE for neuroendocrine tumors.
Medically reviewed content for education only — not a substitute for advice from your oncology team.