Nuclear Medicine

In this Article

What is Nuclear Medicine?

Nuclear medicine uses radiation to diagnose and treat certain conditions. A radioactive tracer, or radiotracer, is injected into your body or sometimes inhaled or swallowed. The radiotracer has a little bit of radioactive material combined with something else. The other ingredient depends on what the doctor is testing. Learn more about nuclear medicine.

Nuclear medicine for diagnosis

When used to diagnose a condition, nuclear medicine gives doctors a way to see what is happening in your body. A radioactive tracer, or radiotracer, is injected into the body or sometimes inhaled or swallowed. The radiotracer contains a little bit of radioactive material combined with another ingredient, which differs depending on what the doctor is testing.

The radiotracer goes to the part of the body your doctor wants to learn more about. Then, the doctor uses a scanner like a PET or SPECT scan to find the radiation — the energy coming from your body — to see what is happening.

For example, nuclear medicine can show how your blood is flowing, where the blood flow is blocked, and where a lot of blood is flowing. It can also show how quickly a part of your body is using glucose (sugar) for energy. Cancer cells use glucose faster than other cells, so this might show where cancer cells are.

Nuclear medicine for treatment

Nuclear medicine can be used to treat a disease by placing small amounts of radioactive iodine or other substances in specific locations within the body. The radiation cells shrink or kill cancer cells in that specific area. Examples of diseases treated this way are hyperthyroidism and some blood cancers and lymphomas. Nuclear medicine can also be used to reduce the pain of bone cancer.

What are the Risks and/or Side Effects?

The amount of radiation you get (and the risk involved) from nuclear medicine is about the same as you get from a chest x-ray or CT scan.

Nuclear medicine uses small doses of radiation. Radiation can increase your risk of cancer. But when you need the test, the risk for such a small dose of radiation is worth the benefit you get from diagnosing or treating your illness. So the risks of nuclear medicine are similar to those of an x-ray or CT scan. The doctor will keep the radiation as low as possible to do the test or give your treatment.

Radiation from these tests may not be safe for those who are pregnant or breastfeeding. Talk with your doctor about the risks for you and your baby.

Most people do not have side effects from these procedures and can go back to their normal activities when the test is over.

What are the Benefits?

Nuclear medicine is one of the few ways for a doctor to understand what is happening in your body. Sometimes it is the only way. This information helps your doctor give you the right treatment.

A diagnostic test that uses nuclear medicine is not invasive (no surgery needed) or painful and is relatively easy for you.

How Do I Prepare?

Your doctor will tell you what you can eat or drink and what to avoid before the test.

Be sure to tell the doctor about any medicines you take (including prescriptions, over-the-counter medicines, inhalers, patches, vitamins or herbal remedies) and any allergies you have.

How is it Done or Administered?

Nuclear medicine is usually done in a hospital but as an outpatient.

Depending on the test, the radiotracer will be injected or inhaled or swallowed. Sometimes the scan can be done right after getting the radiotracer. However, some people may have to come back in several hours or even several days.

You may go inside a machine for the scan. Tell the person who is doing the scan if you are claustrophobic (afraid to be in small spaces). Sometimes the scan is done with a small, hand-held device that the doctor passes over the part of the body being tested. Either way, getting good images requires that you must hold very still while the scan is happening.

The person doing the scan may check the images before letting you go to make sure all the images are good.

When Will I Know the Results?

You will get the results of the test once the nuclear medicine doctor and doctor who is treating you have had a chance to look at the images and interpret them. It may take several days.

What are Follow-up Requirements and Options?

Your follow up will depend on the results of the test. The doctor who is treating you will tell you about follow-up requirements and options when you get the test results.

What Should I Expect During Recovery?

  • Nuclear medicine used to diagnose a condition. Unless your doctor tells you otherwise, you should be able to do your normal activities after the test.
  • Nuclear medicine used to treat a condition. Recovery from treatment with nuclear medicine depends on the illness and the specific treatment. Ask your doctor what to expect from your treatment.