Can a PET scan cause cancer?

A PET-CT combines metabolic imaging with CT imaging. The injected FDG Radiotracer gives off radiation that the scanner detects, and the CT portion also uses X-rays. The tracer leaves the body naturally over time, helped by drinking fluids and urinating when the imaging team says it is appropriate. Radiation risk is related to total exposure across a person's medical history, so clinicians consider earlier scans, the reason for imaging, and whether another test could answer the same question. The images may help assess a known cancer, look for spread, or investigate an unexplained finding; they do not by themselves prove that a spot is cancer.

Tell the imaging team if you are pregnant, might be pregnant, breastfeeding, have diabetes, or have recently received another scan involving radiation. Follow the centre's instructions about fasting, medicines, activity, and glucose testing because these can affect the image. Ask why the scan is being recommended, what decision it will guide, and whether the result could change treatment. A PET-CT Scan page can help you understand the usual process before the appointment.

Contact the imaging service promptly if you develop swelling, wheezing, faintness, or a widespread rash after the injection. Seek urgent medical help for trouble breathing, collapse, or rapidly worsening symptoms. These reactions are uncommon, but they need immediate assessment. For questions about long-term exposure, bring the dates and types of previous imaging to the clinician arranging your scan.

What specific question will this scan answer? How will the PET and CT findings be interpreted together? Have my previous scans changed the recommendation? Do pregnancy, breastfeeding, diabetes, or kidney problems affect my preparation? What happens if the scan shows an area of increased activity?