Will I be radioactive after a PET scan?

A PET scan does use a small amount of radioactive material, called a tracer, which is injected into your body before the scan. The tracer, radioactive glucose, travels through your bloodstream so the scanner can detect where cells take it up — cancer cells often take up more glucose than healthy cells, which is what helps the scan find them.

After the scan, the radioactive material does not stay in your body indefinitely. It loses its radioactivity over time and may leave the body through urine or stool as your body processes it naturally. This is a normal, expected part of how nuclear scans work.

If you have specific concerns, such as being around young children or others soon after your scan, ask your care team for guidance based on your particular procedure and dose. They can tell you whether any precautions apply to your situation in the hours after your appointment.