For Caregivers

What Is MIBG?

I-131 MIBG is a drug that is used to treat neuroblastoma. It is a clear liquid, made of two materials: metaiodobenzylguanidine, or MIBG, and I-131, a radioactive material. The MIBG carries the radioactive I-131 specifically to your child’s tumors, where it targets the cancer cells over many weeks.

MIBG treatment process

Before infusion

  • Before your child receives MIBG he or she will be given oral potassium iodide (also referred to as “SSKI”). This protects the thyroid from I-131. Your child will continue to take this for a total of six weeks after MIBG treatment.
  • Many patients will receive a bladder catheter to drain urine and reduce radiation exposure to the bladder. Younger children may also receive an IV medication to keep them calm while they have the catheter in place, and oral medicine to prevent bladder spasms while the catheter is in place. The medical team will talk to you about this if it is necessary for your child.
  • Your child will also receive an IV anti-nausea medication, such as Zofran, before the MIBG treatment starts.

During infusion


Your child will receive MIBG slowly using an infusion pump like the one shown above. The pump sends the I-131 MIBG into the bloodstream through an IV or central line. The process takes about two hours, and is not painful. Your child’s blood pressure and heart rate will be checked every 15 minutes during the infusion. Occasionally, a patient’s blood pressure goes up a bit, requiring medicine for a few days.

Inside your child’s body

Once the radioactive material enters the bloodstream, it travels to the cancer cells in your child’s body. A significant amount of the radioactive material is filtered into the kidneys, and passed out of the body through your child’s urine over several days. Your child may have a bladder catheter, if he or she is too young to urinate every two hours in the toilet. Some of the radioactive material will leave your child’s body through sweat, saliva and feces.

Outside your child’s body

The radiation leaving your child’s body in the days following treatment is what makes MIBG so different from other cancer treatments. Because MIBG is radioactive, it’s handled very carefully. We take many precautions to ensure your safety, and the safety of other patients and staff, while your child is treated. To limit radiation exposure to others, you will be the primary caregiver for your child, who will stay in a special room at the hospital until the radiation has gone down to a safe level. This usually takes 2 to 5 days.