MIBG Scan

What is a MIBG scan?

MIBG stands for meta-iodobenzylguanidine. It is a molecule absorbed by some types of tumors, particularly neuroblastoma.

An MIBG scan is a test that helps locate and diagnose tumors. It can show neuroblastoma inside the body. This test can show when cancer has spread to the bone and other organs. It can also show when cancer responds to therapy.

How an MIBG scan works

The test takes place over 2 days. Your child does not have to be admitted into the hospital for the test.

On the first day

• Your child will get a tracer injection. The injection includes MIBG combined with a small amount of radioactive iodine. Neuroblastoma cells should absorb the tracer and show up when scanned the next day.
• You and your child can return home (or to patient housing).
• You will wait 24 hours to allow time for the tracer to move to tumor sites.

On the second day

• You and your child will return to the center for the scan.
• Your child will lie very still on a table during the test. The test can last 1–2 hours, depending on your child’s height.
• The care team secures your child with soft safety belts. The table slowly moves through a machine called a scanner.
• The scan uses a gamma camera that takes pictures of areas that absorbed tracer. Doctors look for bright spots. The bright spots may indicate cancer.
• An MIBG scan does not hurt. But a child who finds it hard to stay still might need sedation. If your child moves during the test, the scan will blur and must be repeated.
• After the test, your child may leave and resume normal activities, unless they are sedated. Patients who are sedated must recover from anesthesia.

Before the MIBG scan

• Check insurance. If you have private insurance , check with your provider to find out how much of the test’s cost will be covered. They can also tell you how much you will need to pay.
• Ask questions. Talk with your care team about any concerns.
• Explain the test to your child. Make sure your child knows the reason for the MIBG scan. You may want to ask a child life specialist to help.
• Take prescribed medicine to protect thyroid. The doctor may prescribe potassium iodide drops to take before the injection until the day after the scan. The drops protect your child's thyroid gland from absorbing any radioactive iodine.

How to prepare for an MIBG scan

Tell your child’s treatment team about:

• Allergies
• Other medical conditions
• Medicines (even over-the-counter ones), vitamins, and herbs
• Any chance of pregnancy

What to expect the day of the injection

Arrive a few minutes early to check in. You may be asked to sign a consent form. It states that you understand the benefits and risks of the scan and agree to have the test.

When your child is called back, a nurse or nuclear medicine technologist will greet you and explain what will happen. A child life specialist may be there as well.

A nurse or technologist will inject the tracer through an IV. After the injection, the IV will be removed. Then you and your child may leave the area and resume normal activities.

Pregnant women should not have direct contact with the patient for 12 hours after the MIBG injection, or until instructed by the nuclear medicine staff.

What to expect during the scan

Your child should wear loose, comfortable clothing and leave jewelry and metal objects at home. Your child may need to wear a hospital gown.

Arrive a few minutes early to check in. When your child is called, the staff will again greet you and explain what will happen. A child life specialist may be there as well.

Your child will lie on the scanner table. A gamma camera will take pictures that will help the doctors see if there is cancer and if it has spread to bones or other parts of the body.

Receiving the results of an MIBG scan
A nuclear medicine physician will look at the scan. This doctor will prepare a report and share it with the doctor who ordered the test.

Your child’s oncologist will share the results with you.