When is PET-CT scan recommended for cancer of unknown primary?

PET-CT combines a scan showing body structure with images of areas that absorb a tracer. This can help the team look across the body for an active tumour focus, map known disease, and choose a suitable area for biopsy. Findings can also help distinguish areas that need closer review from changes caused by inflammation or other conditions. The scan is one part of the diagnostic process; it does not always identify the starting organ and cannot replace pathology when tissue is needed.

Follow the imaging unit's instructions about eating, drinking, medicines, and blood glucose. Tell the team about diabetes, pregnancy or breastfeeding, allergies, recent illness, and difficulty lying still. Wear comfortable clothing and remove metal items if asked. Arrange enough time for preparation, tracer administration, and imaging. Afterward, follow the department's advice about fluids, activity, and contact with others. Ask how and when the results will be reviewed with biopsy and other scans.

Seek urgent help for severe breathlessness, chest pain, sudden weakness, confusion, heavy bleeding, or rapidly worsening pain. Contact your cancer team promptly for new persistent symptoms such as unexplained weight change, enlarging lumps, ongoing fever, or worsening fatigue. These symptoms deserve assessment independently of whether a PET-CT has been scheduled.

Ask what unanswered question the scan should address, whether a biopsy is planned, how tracer preparation affects your medicines, and what the next step will be if the primary site remains unknown.