We know: nuclear medicine is an intimidating name for a medical procedure. However, this non-invasive technology helps us identify diseases in their earliest stages when we can more likely treat them successfully. Nuclear medicine procedures also help us assess how well you are responding to treatment for a disease, such as cancer.
Nuclear medicine uses small amounts of a radioactive material (called a radiotracer), which we inject into your veins. When the radiotracer accumulates in the area of interest, it gives off a small amount of energy in the form of gamma rays. We use special types of cameras to view these rays. Nuclear medicine is about looking at physiological processes in the body, rather than the anatomical structure.
A disease such as cancer begins with microscopic cellular changes. It takes time for these cellular changes to become large enough to be detectable on an imaging test, which is part of the reason we don’t detect many cancers until they are advanced. However, these areas of high chemical or metabolic activity absorb the radiotracer—even if they are small — so, they show up on a scan. Using nuclear medicine sometimes eliminates the need for an invasive procedure, such as a biopsy.
We commonly use nuclear medicine to detect cancer, heart disease (for example, to detect blockages in the coronary arteries), brain disorders (such as Alzheimer’s or Parkinson’s disease) and disorders of the lungs, bone, kidney or thyroid. However, we can use nuclear medicine for just about any part of the body.
Tell your doctor about all medications you are taking prior to your procedure.
What happens during a nuclear medicine procedure?
We’ll ask you not to eat (not even gum) for four to six hours prior to your procedure and to only drink water so you don’t alter the distribution of the tracer. After you arrive, we’ll administer the radiotracer, usually by way of an injection (you can also swallow it or inhale it as a gas). It generally takes 30 minutes to an hour to distribute throughout your body. If you’re undergoing a CT scan, we may also ask you to drink a contrast material. Then we’ll conduct one of the following scans. Be sure to stay still during the scan so we get a good image. The scan takes 15 minutes to an hour.
The tube in a PET, CT or PET/CT scanner is narrow. Talk to your doctor If you’re claustrophobic or anxious about the procedure. He or she may prescribe medicine to help you relax.