PET scan

Doctor looking at x ray CT scan

A PET scan combines an injection of radioactive sugar and a CT scan. It can give your doctor more information about where the cancer is.

Before the test

You may be asked not to eat or drink anything for a few hours before the test. You may be asked to avoid sugar or caffeine for a time too.

You will have an injection of radioactive sugar into your veins, usually in your arm. You will have to wait for around an hour for the sugar to travel around your body. You might like to bring earphones so you can listen to music while you’re waiting.

During the test

About an hour after the injection, you will have a scan. You will lie on a table which moves through a scanning ring. The radioactive sugar shows up where the cancer cells are, so your doctor can see if the cancer has spread to other tissues and organs.

How long does it take?

After the injection you will have to wait about an hour before having the scan, to let the radioactive sugar spread through your body.

Are there risks / side-effects?

PET is safe to use and there are no side-effects.

You will be slightly radioactive after the PET scan, so it is best not to have close contact with pregnant women, babies or young children for a few hours after the scan.

PET scan video

Cancer Research UK has a very helpful video on this.

For more information

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