What should you know about PET scans in oncology?

PET imaging uses a radiotracer, often FDG, to show patterns of cellular activity. CT adds a map of the body's structures, allowing the specialist to locate an active area more precisely. Activity can also come from infection, inflammation, healing, normal organs, or treatment effects. For that reason, a PET finding does not establish cancer without the rest of the clinical picture.

Depending on the situation, oncology teams may use PET-CT to investigate a finding, assess the extent of known disease, examine lymph nodes or distant sites, plan treatment, or compare images during follow-up. It can contribute to care for lymphoma and for cancer where the original site remains unknown. The scan is one part of a decision process that may include pathology and other imaging.

Follow the imaging centre's instructions about fasting, fluids, medicines, and physical activity. Tell staff about diabetes, pregnancy or breastfeeding, recent infection, and previous reactions or access difficulties. Rest quietly after receiving the FDG radiotracer and remain still during image collection. Ask how to manage your regular medicines and whether you need someone to accompany you. The PET-CT Scan, FDG Radiotracer, and PET-CT Scanner pages explain the components of the appointment.

Contact the centre if you cannot meet the preparation instructions or need an accommodation for movement, anxiety, or communication. Report an unexpected reaction after the tracer. Seek emergency care for severe breathing difficulty, fainting, or sudden severe illness. Arrange a review of the report with the clinician who knows your diagnosis, because scan language can be misleading without its clinical context.

What decision will this scan inform? Which body regions are included? Could inflammation or treatment affect uptake? How will this result be combined with biopsy or other imaging? When should I expect the findings and follow-up plan?