What is a gallium scan?

A gallium scan is a medical imaging test. Your healthcare provider may recommend it to look for and help treat certain health conditions. It's a type of nuclear medicine scan.

Nuclear medicine uses radioactive materials to create images of the body. These materials make radiation. Radiation is a kind of energy. Special machines are able to detect this energy. With this information, they can form an image of your body.

A gallium scan uses gallium citrate. It’s a drug that has very small amounts of radioactive gallium. A day or two before your scan, your healthcare provider injects the gallium citrate into a vein in your arm. The gallium then travels all over your body. It builds up in any cells that are actively dividing, such as cancer cells. It also binds to cells and proteins involved in inflammation in your body.

When you get the actual gallium scan, you'll lie on your back on a scanner table for about an hour. A special camera can then detect where the gallium has built up in your body. It can then form an image to show where the cells of your body are reproducing the most. The scan might give your healthcare provider information about cancer, infection, or inflammation in your body.

Why might I need a gallium scan?

A gallium scan identifies the cells that are dividing most quickly in your body. It can help detect some cancer cells. It can also help show cells that are rapidly reproducing or responding to an infection somewhere in your body.

People with lymphoma (cancer of the lymph system) may need gallium scans. The scans can help show how much the disease has spread. They can also show how effective chemotherapy or another treatment is.

Healthcare providers don’t use this test to detect cancer as often as they once did. That’s because newer imaging techniques, like positron emission tomography (PET), are now available. Gallium scans don’t detect all forms of cancer. But they can still be helpful in tracking some types.

You also might need a gallium scan to diagnose or track the course of the following conditions:

• A fever without a known cause

• Certain lung infections

• Infection of the bone (osteomyelitis)

• Inflammation of the lungs (sarcoidosis)

• Lung damage from certain drugs

What are the risks of a gallium scan?

A gallium scan is a very safe procedure. But it does have some risks. These include:

• Allergic reaction, which rarely might cause trouble breathing

• Rash

• Nausea

Your risks might differ depending on your age and other medical conditions. Talk with your healthcare provider about any concerns. Pregnant women should avoid the scan if possible. It may not be safe for the developing child.

The scan uses a small amount of radiation. Although large amounts of radiation can increase your risk of cancer, the exposure from a gallium scan is very small. It’s less than what is used for many types of X-rays. Your body naturally clears the gallium from your system over several days. The radioactive material isn't a danger to anyone around you. You also don’t need to take any special precautions.

How do I get ready for a gallium scan?

Before you get the gallium citrate injection, your healthcare provider will review your health history. Be sure to talk about:

• Any recent symptoms

• Medicine allergies

• Any prescription medicines

• Any over-the-counter medicines you're taking, especially those that contain bismuth

Tell your healthcare provider if you might be pregnant, or if you're breastfeeding. You'll be asked if you have had any recent medical tests that use barium, such as a barium swallow exam or CT scan.

You typically go to the nuclear medicine department at a scheduled time to get the injection of gallium citrate. You'll likely get the injection in a vein in your arm. It may sting a little. You can then go home and resume your normal activities. Tell your healthcare provider if you have any reactions to the injection, such as prolonged nausea.

Your healthcare provider will let you know if you need to make any changes to your normal medicines, diet, or activities. You might need to take a laxative for several nights before your scheduled scan. You also might need to have an enema a couple hours before your exam. It may help to get a better image.

What happens during a gallium scan?

It's important to carefully follow your healthcare provider’s instructions about when to return for the gallium scan itself. It might be several hours to a few days later, depending on the reason for your scan. You need to have your scan at exactly the right time. Don’t miss it unless it's an emergency. Reschedule as soon as possible, if needed.

Your healthcare provider can tell you what will happen during your scan. In general, you might expect the following:

• You’ll need to empty your bladder beforehand. You will also have to remove any metal jewelry or objects.

• You won't need sedation for your scan. If you're very nervous, you might receive a medicine to help you relax. The scan itself will be painless.

• The scanning machine may look like a firm bed with an overhead camera. Your healthcare provider will position you underneath this camera.

• You’ll need to lie very still during the scan, which might last about an hour. Staying still will help provide a clear picture.

• As you lie on your back, the scanner will move above you. It will take pictures over the length of your body.

What happens after a gallium scan?

You usually can go home right away and resume all your normal activities. The scan itself shouldn't cause any side effects. The gallium will leave your body over the next several days. Your healthcare provider might give you more instructions. For example, drinking extra water may help flush out the gallium.

A healthcare provider specializing in reading these scans will need to view and interpret the images. That person will send the results to your primary healthcare provider. The image will look like a grey outline of your body with certain darker areas.

The results of your scan may help your healthcare provider create a treatment plan for you. You might need another scan to see how your treatment has progressed.

Next steps

Before you agree to the test or procedure, make sure you know:

• The name of the test or procedure

• The reason you are having the test or procedure

• What results to expect and what they mean

• The risks and benefits of the test or procedure

• What the possible side effects or complications are

• When and where you are to have the test or procedure

• Who will do the test or procedure and what that person’s qualifications are

• What would happen if you did not have the test or procedure

• Any alternative tests or procedures to think about

• When and how you will get the results

• Who to call after the test or procedure if you have questions or problems

• How much you will have to pay for the test or procedure