MIBG Scan

What is an MIBG scan?

An MIBG scan is a nuclear imaging test that can help healthcare providers diagnose and assess certain types of tumors. Nuclear imaging tests use a small amount of radioactive material that is absorbed by tissue in your body.

An MIBG scan uses a radioactive substance called iodine meta-iodobenzylguanidine (MIBG) as a tracer in your bloodstream. A special camera detects the tracer and takes images inside your body.

It’s also called:

• Iobenguane scan.
• Metaiodobenzylguanidine scan.
• MIBG scintigraphy.
• MIBG scintiscan.

What is an MIBG scan used for?

Healthcare providers use MIBG scans to diagnose specific tumors that start in hormone-producing neuroendocrine cells, such as:

• Carcinoid tumors (neuroendocrine tumors).
• Neuroblastoma, a rare cancer that develops in nerve cells, usually in children younger than 5.
• Medullary thyroid carcinoma, a type of thyroid tumor.
• Pheochromocytoma, a tumor in your adrenal glands or other body parts.

Providers may also use MIBG scans to assess whether cancer has spread or if treatment is working.

Who performs MIBG scintigraphy?

MIBG scanning is often performed by radiologists. They’re medical doctors who specialize in diagnosing and treating conditions using imaging technology. The tests are usually done in the nuclear medicine department of a hospital.

How does MIBG imaging work?

Neuroendocrine cells throughout your body absorb MIBG. A special camera can then detect the tracer and produce images. A medical specialist can analyze whether the images appear normal or abnormal.

How do I prepare for an MIBG scan?

Your healthcare provider will ask you to take a medication containing iodine (sometimes called Lugol’s solution) the day before the test. The medication helps protect your thyroid from the radioactive substance. You may need to take it for a couple of days afterward as well.

What should I avoid before an MIBG scan?

Before an MIBG scan, your doctor may ask you to stop taking certain drugs that can interfere with the test, including:

• ACE inhibitors.
• Allergy and cold medications.
• Amiodarone for arrhythmia.
• Antidepressants.
• Calcium channel blockers.
• Opioids.

Tell your healthcare provider about all the medications you take, including prescription and over-the-counter. They’ll explain which ones you should stop taking, and for how long, before an MIBG scintiscan.

What can I expect during an MIBG test?

MIBG scintigraphy is done in stages over several days:

1. A healthcare provider injects the tracer into a vein in your arm or hand.
2. The tracer needs about 24 hours to circulate throughout your body.
3. The next day, you’ll come back for your first scan.
4. Your healthcare team will ask you to remove all jewelry and clothes and wear a hospital gown.
5. You’ll lie very still on a table under a scanner, which will move around and take pictures inside your body.
6. Most people have to return the next day or over the next several days for repeat scans.

How long does MIBG scanning take?

An MIBG test usually involves two to four visits. Each scan takes an hour or two.

What can I expect after MIBG scans?

MIBG scintigraphy is an outpatient procedure. You should be able to go home the same day after each scan.

It will take a few days for the radioactive substance to exit your body. Drink plenty of fluids to help flush it out through your pee and poop. Wash your hands well after going to the bathroom to clean any traces of MIBG from your hands.

If you’re currently breastfeeding, plan to use formula for at least a full day after the injection.

What are the risks of an MIBG scintiscan?

MIBG scans are very safe. There’s a small risk of increased blood pressure after the tracer injection. But blood pressure almost always returns to normal within a day or two. Your healthcare provider may ask you to stay in the office for 30 minutes after the injection to check your blood pressure.

The radioactive tracer can harm a developing fetus, so the test may not be right for pregnant people.

How soon will MIBG results be available?

After the final scan, it usually takes a couple of days to get results. A radiologist will analyze the images, looking for spots where the tracer collected, which may indicate a tumor. They’ll write a report for the healthcare provider who ordered the test. The healthcare provider will discuss the results with you and recommend next steps.

How accurate is an MIBG scan?

The results of an MIBG scan are relatively reliable, with about 85% accuracy.

A note from Cleveland Clinic

If your healthcare provider suspects that you have a neuroendocrine tumor, they may order an MIBG scan. A special camera takes pictures inside your body after your provider injects a radioactive substance (tracer) into your bloodstream. Neuroendocrine cells absorb the tracer, which can be seen in the images.