What is an MIBG scan?
Metaiodobenzylguanidine (MIBG) is an agent that is similar to adrenaline and localizes in certain types of tumors in the body called neuroendocrine tumors. MIBG is labeled with a small amount of radioactive material, and pictures can then be made of the distribution of this material after it is injected intravenously. For this procedure, your body is exposed to a small amount of radiation.

When is it used?
An MIBG scan is used when your doctor suspects or has proof of a neuroendocrine tumor. The scan will determine if your tumor accumulates this agent, and, if it does, the distribution of tumor in your body.

What should my health care professional know before I have this test done?

• Are you allergic to x-ray dye (iodinated contrast material)?
• Do you have any other allergies?

How do I prepare for an MIBG scan?
You will be given water or juice containing one drop of iodine to take before the injection of MIBG. You are to continue to take one drop of iodine mixed in water or juice twice a day for six days after the injection. This small amount of iodine causes any radioactivity that comes off the MIBG to be excreted from the body so that there is no accumulation of radioactivity in your thyroid gland.

What happens during the procedure?
If you have not received the iodine drops before coming to nuclear medicine, you will receive them before the injection of the MIBG. The MIBG will be administered through an intravenous injection. You will then be asked to return in one or two days for the pictures to be taken.

For the pictures, you will be placed on an imaging table. The pictures are taken by detectors that will be above and below your body for the procedure. The pictures will take approximately 30 minutes.

What happens after the procedure?
Generally, there are no special measures to take after the procedure. You do not need to have someone with you for the procedure.

What are the benefits of this procedure?
The procedure will help your doctor diagnose your problem. It will tell your doctor whether the agent localizes in an area to suggest that you have a neuroendocrine tumor.

What are the risks associated with this procedure?
You are exposed to radiation, but the amount of radiation that you receive is not considered threatening. Pregnant and lactating women should not have an MIBG scan.

There is a small risk that you may have an allergic reaction to the iodine drops. If you have an allergy to iodine, tell the technologist before the injection of the MIBG. If you develop an allergic reaction to the iodine drops, the drops can be discontinued.

When should I call the doctor?
The results of this examination will be available to your referring physician on the day of the examination.

This article is intended as a resource for patients receiving their cancer care at Duke University Hospital or Duke Clinic. It is not intended to substitute for medical advice from your health care team. If your doctor’s instructions differ from the information in this article, please talk with your doctor before making any changes.

Source: Duke Cancer Patient Education Program / Patient & Family Education Committee 8/00