I-131 MIBG therapy is a treatment that uses a radioactive medicine to target and kill cancer cells. It is used to treat neuroblastoma and some other neuroendocrine tumors.
MIBG stands for metaiodobenzylguanidine. It is a liquid absorbed by neuroendocrine tumor cells. MIBG is combined with radioactive iodine (I-131), which kills cancer cells.
I-131MIBG therapy is most often used for high-risk neuroblastoma. It is not approved by the FDA and may be offered as part of a clinical trial. Patients get I-131 MIBG therapy when standard treatments alone are not enough or if cancer comes back after treatment. MIBG therapy is often used along with chemotherapy or other therapies.
The I-131 MIBG medicine is given as a liquid into a vein (infusion). Because the therapy involves radiation, patients and family caregivers stay in the hospital in a specially designed hospital suite for a few days after treatment.
MIBG therapy is different from an MIBG scan. An MIBG scan is an imaging test that uses a lower dose of a radioactive tracer to take pictures of neuroblastoma and other neuroendocrine tumors. Read more about MIBG scans.
A nuclear pharmacist combines MIBG with radioactive iodine (I-131). The MIBG carries the radioactive iodine to the neuroblastoma tumor. The tumor absorbs the MIBG medicine, and the radioactive iodine kills the cancer cells. Because MIBG targets cancer cells, it lessens damage to nearby healthy cells.
Each child’s treatment is personalized based on their disease and health. Your child gets the most effective dose to destroy cancer that they can safely receive.
Radiation Safety After I-131 MIBG Therapy
Before MIBG treatment, your child will be admitted to the hospital. After the medicine is given, radiation can leave your child’s body through urine (pee), stool (poop), sweat, saliva (spit), blood, and vomit. Your child will stay in the hospital for several days after treatment. During that time, special precautions are needed to protect others from radiation. These include:
- The patient and their family caregiver will stay in a special set of hospital rooms.
- Caregivers should limit time spent in the patient room as much as possible and follow the radiation safety guidelines provided.
- All caregivers must wear protective gear (gown, gloves, mask, and shoe covers) when providing patient care.
- A special device (dosimeter) will be used to monitor radiation levels.
Your care team will review safety instructions with you and teach you how to care for your child after I-131 MIBG therapy.
Preparing for MIBG treatment
Your care team will explain what to expect and review safety instructions. You will review and sign a caregiver agreement before your child is admitted to the hospital.
Before therapy begins, your child will be admitted to the hospital. One adult family caregiver must stay at the hospital with your child. It can be helpful to plan for more than one caregiver so that you can take turns. Pregnant women should avoid all patient contact until the radiation levels are safe.
Your child and their caregiver will stay in a specially designed group of rooms. These rooms have safety features to prevent radiation from the MIBG treatment from harming others.
Your child will be in the patient room and at a distance from others for most of their hospital stay. Health care providers and family caregivers will be in the patient room for brief periods to provide treatment and care. Parents and family caregivers can see and talk with their child at any time from the parent room.
A child life specialist and other care team members can help prepare you and your child for MIBG treatment and explain MIBG therapy in age-appropriate ways. To prepare your child, it can help to talk about and plan for:
- Staying in the hospital and keeping a distance from others for a few days
- Sleeping alone in their own bed
- Games and activities they might want to do during their stay
Planning ahead can help keep your child more comfortable and entertained during their hospital stay.
Planning for medicines
Before treatment, tell your care team about any medicines, vitamins, or supplements your child takes. Bring all of your child’s medications with you so you have them when you leave the hospital.
Many medicines can affect how MIBG works. A few common medicines may include:
Your care team will discuss your child’s medicines with you and let you know if some medicines should be stopped before MIBG therapy. Your care team will go over this information with you. Do not stop giving your child any medicines unless your care team tells you to do so.
What to bring to the hospital
Your child will not be able to leave their room during their stay for MIBG therapy. You may bring the following items to the hospital for your child:
- Toys and games
- Movies
- Books or other activities
- Favorite snacks, foods, or drinks
- Eyeglasses if needed (patients can not wear contacts)
Pack items that can be left behind after use or wrapped in plastic for safety. Do not bring favorite pillows, blankets, or stuffed animals. For safety reasons, all non-disposable items used in the patient room will be stored at the hospital for a few months until the radiation safety team clears them. Do not bring personal, sentimental, or irreplaceable items with you for this therapy.
Caregivers should pack closed-toe shoes, comfortable clothing, medications, entertainment, and personal care items. Caregivers who wear glasses or contacts must wear a face shield or goggles while in the patient room.
Stem cell infusion
The radiation from MIBG therapy can damage the bone marrow and temporarily decrease the body’s ability to make new blood cells. To help treat this side effect, your child’s stem cells will be collected from the blood or bone marrow before MIBG therapy begins. After the treatment, the stored stem cells will be given back by infusion to help the bone marrow recover and make healthy blood cells.
Potassium iodide medicine
Potassium iodide is a medicine used to protect the thyroid gland from radioactive iodine. Your child will start taking potassium iodide drops the morning MIBG therapy begins. The medicine stops the thyroid from absorbing the harmful radioactive iodine. Your child will continue the medicine for several weeks after the MIBG infusion.
IV placement
If your child does not already have an IV or central line, the care team will place an IV for the MIBG infusion.
Urinary catheter
Your child will have a urinary catheter, a small tube that drains your child’s bladder of urine (pee). The urine will be collected in a special container. The catheter stays in place while your child is in the hospital.
Most of the radiation will leave your child’s body through their urine. Having a catheter helps limit radiation exposure from using the bathroom and handling body fluids.
Fluids
Your child needs fluids before and after the MIBG therapy. This will help flush out the radioactive iodine from the body.
On the day of the MIBG infusion, your care team will bring the infusion cart into your child’s room. Only essential care team members should be in the room during the infusion. They will wear safety gear and a dosimeter to measure radiation levels. Caregivers can watch from the parent room.
A provider will inject the MIBG medicine through an IV or central line into your child’s bloodstream. The infusion takes 1.5–2 hours. It does not hurt.
Once the infusion is complete, staff will remove the infusion equipment from the room.
Care in the hospital
After the MIBG infusion, your child will stay in the hospital for several days until their radiation levels are low enough to safely go home. During this time, your child will remain in the patient room. The room has lead-lined concrete walls to keep radiation from leaving the room.
Caregivers stay in a parent room next to the patient room. It has a leaded window so caregivers can see their child while being protected from radiation. Patients and caregivers can talk to each other using an intercom system in the rooms.
People enter the patient room through an entry room. It works like a safety zone to help keep everyone safe from radiation. Your care team will give instructions for entry and exit procedures. Before entering the patient room, caregivers and medical staff must:
- Put on radiation safety gear like gowns, gloves, masks, and shoe covers
- Wear a dosimeter (a device that measures radiation levels)
Family caregivers and medical staff will work as a team to provide daily care for your child.
- Nurses will provide more complex care, such as giving IV medicines. They will monitor your child’s blood counts and watch for side effects.
- Family caregivers will help with general patient care such as feeding meals, changing clothes or bed linens, using a bedpan or bedside toilet, brushing teeth, and giving medicines by mouth.
Radiation safety precautions for caregivers
Follow all safety rules as instructed. These rules protect you and others from radiation exposure. Safety guidelines for patient care in the hospital include:
- Limit time spent inside the patient room.
- Wear the provided safety gear and dosimeter to measure your radiation exposure.
- Try to keep at least 6 feet away from your child and stay behind the safety shielding around your child’s bed as much as possible.
- Limit physical contact with your child.
- Do not eat or drink, use the bathroom, or sleep in the patient room.
- Do not bring personal items into the patient room or remove items from the patient room.
Coping with boredom
After MIBG therapy, the biggest challenge is often boredom. Patients must remain in their room and mostly in bed. Quiet activities can help pass the time. Work with your child life specialist and other care team members to plan age-appropriate activities for your child that they can do by themselves. Examples include:
- Playing with toys and games
- Watching movies, listening to music, or reading books
- Playing video games or using a tablet
- Doing crafts, puzzles, or other activities
Side effects of MIBG therapy
Your child may feel tired or sick for a few days. Your child will keep taking potassium iodide drops to protect their thyroid.
Possible short-term side effects include:
MIBG therapy can cause low blood counts 2-3 weeks after therapy. This can lead to symptoms such as fatigue, easy bruising or bleeding, and increased risk of infection. Patients may need a stem cell infusion, blood transfusions, or medicines to treat side effects.
Rare long-term risks of MIBG therapy include thyroid problems, fertility problems, and secondary cancers.
Care at home after MIBG therapy
Your child will stay in the hospital until their radiation levels are low enough to safely go home. This usually takes 3 days or more. Before discharge, your child’s urinary catheter will be removed. After bathing, your child will put on clean clothes. Any clothes or other items will be thrown away or stored at the hospital unless they are cleared by radiation safety staff.
Even after discharge, your child will still have some radiation in their body. Have your child drink lots of fluids to flush radioactive iodine out of the body.
Follow the radiation safety instructions your care team gives you. Safety steps are needed for about 7 days and generally include:
- Avoid close contact: Try to stay at least 3 feet away from your child as much as possible. No hugging, kissing, holding hands, or activities that involve touching or sharing items.
- Safe eating: Have your child use disposable plates, cups, and utensils for eating and drinking.
- No sharing: Do not let your child share games, toys, or personal items.
- Separate sleeping: Do not let your child share a room or sleep in the same bed with another person.
- Bathroom safety: Your child should use a separate bathroom from other family members if possible. After using the bathroom, your child should flush the toilet 2 times. Children should sit to use the toilet and take care to reduce splashing.
- Good hygiene: Be sure your child washes their hands often with soap and water. Have your child bathe daily.
- Avoid public places: Do not take your child to public places or use public transportation.
- Safe handling: Wear gloves when handling items that may have patient body fluids, such as diapers, dirty clothes, or bedding. Wash laundry separately and follow your care team’s instructions.
Your care team will give you specific instructions and let you know when it is safe for your child to be around others, return to school, and do usual activities. This usually happens after about 7 days.
You will receive a radiation safety letter that documents your child's medical condition and treatment in case your child sets off a radiation detector at airports or other places.
Your child will have follow-up appointments to check blood counts and monitor side effects. Your child’s care team will discuss additional tests and treatments that may be needed.
In most cases, your child can return to normal activities 1 to 2 weeks after they go home from the hospital. Your care team will give specific home care instructions after discharge.
When to call your care team
Call the care team right away if your child has:
- A fever of over 100.4°F or other signs of infection such as chills, sweating, or body aches
- Fatigue or weakness that does not get better
- Vomiting or diarrhea that does not stop
- Pain that gets worse or does not go away
- Unusual bleeding or bruising
- Trouble peeing or pooping
- Swelling of the face, feet, or hands
- Any new or unusual symptoms that worry you
Also call your care team if:
- You are not sure how to follow the safety instructions at home
- You have questions about your child’s medicine or care
- You need help with radiation safety precautions (like cleaning, laundry, or limiting contact)
Questions to ask your care team
