Treatments and Services

I-131-MIBG Therapy

What is I-131-MIBG therapy?

I-131-MIBG therapy is a type of radiation therapy used to kill cancer cells in children with certain kinds of cancer. It's a way to get radiation inside your child's body to target cancer cells wherever they are.

The medicine is a clear fluid that looks like water. Your child receives this treatment by infusion through a thin tube into a vein. The fluid contains I-131 and MIBG. I-131 is a kind of radioactive iodine. This is what gives off radiation to destroy the cancer. When it is attached to MIBG (another chemical), it brings the radiation into the tumor.

Once inside the cancer cells, the iodine gives off particles of radiation (beta radiation) that travel outward about half an inch in all directions. This kills the cancer cells and the cells around them.

Who may be helped by I-131-MIBG therapy?
I-131-MIBG therapy is used to treat neuroblastoma and some tumors of the adrenal glands (pheochromacytoma).

Radiation works well against neuroblastoma. But neuroblastoma may spread to many places in a child's body. So the most common way of giving radiation – sending a beam of radiation toward 1 spot – is not always useful. I-131-MIBG therapy is a way to get radiation to neuroblastoma cells all around the inside of your child's body through the bloodstream.

This is a newer option, so usually it is offered only through research studies (clinical trials).

At Seattle Children’s, I-131-MIBG therapy may be an option for children with high-risk neuroblastoma in these ways:
- Our doctors have worked with the research groups Children’s Oncology Group and New Approaches to Neuroblastoma Therapy to make I-131-MIBG available for children with disease that does not respond well to treatment (refractory) or that has come back (recurrent).
- A clinical trial for children who are newly diagnosed with high-risk neuroblastoma.
In the future, I-131-MIBG therapy may be used as part of treating all children with high-risk neuroblastoma. Before this can happen, scientists need more research results to tell whether standard treatment plus I-131-MIBG therapy may work at least as well as standard treatment alone.

What's special about I-131-MIBG therapy at Seattle Children's?

Seattle Children's is the only hospital in the Pacific Northwest and 1 of only 20 centers in the country that offer I-131-MIBG therapy for children. It's part of our commitment to bring the best and newest treatments to all children with cancer.

We take great care to treat your child safely while keeping your family, other patients and the hospital staff safe. Seattle Children’s has special rooms, equipment, and a full team of healthcare providers with special training to offer this treatment.

What to Expect

We treat your child at our hospital campus in Seattle. The I-131-MIBG fluid is slowly pumped through a tube into your child's vein so it can travel through their body via their bloodstream. It takes about 2 hours. The tube is called an intravenous (IV) line or central line.

After the infusion, you and your child stay in the hospital for about a week. For 5 to 7 days, your child's body fluids (like pee, sweat and spit) will give off radiation that could harm others. Our team follows special plans to care for your child while making sure to contain the radiation.

Parents are key members of the care team. During the week after the infusion, you will need to provide some of your child's care. Before treatment starts, the team will give you detailed training about what you will need to do. We work closely with you during your child's hospital stay.

These guides prepare you to help care for your child during treatment in the hospital and at home:

I-131 MIBG Treatment Booklet (PDF)
Going Home After MIBG Treatment (PDF)