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A PET (positron emission tomography) scan shows how organs and tissues work in the body.
PET scans can help doctors diagnose and treat cancer.
They can see and track the activity of cancer and other cells. PET scans can measure:
Sometimes a PET scan is performed at the same time as a computed tomography (CT) scan. A PET-CT scan collects images from both PET and CT scans and combines them.
A PET-CT scan gives doctors information about the function, size, shape, and location of cancer and the areas around it.
The CT scan is first. It creates anatomic pictures of the body’s organs and structures.
Then, the PET scan creates pictures showing metabolic or functional changes in tissues.
A PET-CT scan collects images from both PET and CT scans and combines them.
PET scans can measure the level of glucose, or sugar, in cells.
Before the PET scan, your child will get an injection with a radioactive tracer. It's a form of glucose with a small amount of radioactive material attached.
Cancer cells may grow and divide quickly. So, they absorb much more glucose than normal cells. The radioactive material attached to the glucose molecule causes it to light up on the PET scan.
Every pediatric center is different, but here’s what you can generally expect.
When the machine is turned on your child will see the red laser lights of the scan but will not feel them.
Be sure to talk with your child’s care team. But these general tips can help.
The level of radiation is very small. Your child’s care team will discuss the risks and benefits involved. Patients and families should talk to their care team if they have any concerns.
The radioactive material does not stay in the body long. Through the natural process of radioactive decay, it will lose its radioactivity over time. It may also pass out of the body through urine or stool during the first few hours following the test.
The medical team will likely tell you to be sure your child drinks plenty of water to help flush out the radioactive material.
Even though the amount of radioactivity is very low, you should follow these precautions when caring for your child after the scan:
A physician who has specialized training in nuclear medicine will analyze the images. They will send a report to your child’s doctor. The doctor will go over the information during your child’s next appointment.
Reviewed: January 2022