Positron Emission Tomography (PET) scan
A PET scan is a whole body scan that uses a small amount of radioactive liquid to take pictures of cancer in the whole body. The amount of radiation you're exposed to is small, and the risk of harm is low.
Your doctor may recommend a PET scan to find cancer in your head and neck, or to see if cancer has spread to other parts of your body
Before a PET scan, you will be given a needle (injection) containing a radioactive sugar (tracer). You will then need to wait between 30 and 90 minutes to let the mixture move around your body.
The radioactive sugar goes to parts of the body that have lots of cells growing, to help show where the cancer is. Because cancer cells absorb more radioactive sugar mixture than healthy cells, cancer cells show up brighter on the PET scan.
Before you have a PET scan, speak with your doctor about the benefits and risks and any other questions you have.
You will be asked to avoid hard exercise for a couple of days and to stop eating a few hours before the PET scan. If you have diabetes, you will need special instructions to get ready for the scan because high blood sugar levels can affect the result of a PET scan.
During the PET scan, you will lie on a table while it moves through the PET machine. It is important to lie still during the scan and not to talk, otherwise normal muscles will show up on the scan. The machine will send pictures to a computer screen. Your doctor can look at the pictures on the computer screen to check for any signs of cancer or if the cancer has spread. It is important to know that other illnesses than cancer, such as infection, can also show up on a PET scan.
A PET scan is painless and usually take about two hours.