What is MIBG?
MIBG, called meta-iodobenzylguanidine, is a chemical that started as a blood pressure medicine. It was found to be preferentially picked up by neural crest cells which give rise to, among other things, parts of your adrenal glands. Neural crest cells can also give rise to a type of cancer called neuroblastoma. Neuroblastomas are in a class of tumors (called neuro-endocrine tumors) that will take up MIBG and can respond to treatment with MIBG.
How is MIBG treatment used?
Roughly 80-85% of neuroblastomas will absorb MIBG. There are really 2 ways in which MIBG treatment is used. In both methods, the MIBG chemical is attached to an iodine molecule that has been made radioactive. The radioactivity can be either a low-dose or a high-dose.
The low-dose radioactive form of MIBG (called I-123 MIBG) is used for x-rays that pinpoint the location of the main neuroblastoma tumor as well as to see if it has spread to other areas of the body like the bones, bone marrow, liver, lymph nodes, lungs, or brain.
The high-dose radioactive form of MIBG (called I-131 MIBG ) is used for treatment. I-131 MIBG is a very effective medication when used to treat neuroblastoma that has responded well to traditional treatments. Once the radioactive MIBG molecule has been picked up by the neuroblastoma cell the radiation will typically kill the cancerous cell in much the same way that radiation beams are used to kill breast, lung or brain tumors. The advantage to MIBG is that the radiation does not affect normal tissues to a great degree as it does given in the more traditional “external beam” method. Basically, it’s a way of targeting radiation therapy specifically to tumor cells by taking advantage of the fact that MIBG is not absorbed or used by any other cells in the body.
What are the long-term effects/risks of treatment with MIBG?
- Low function thyroid gland,
- Difficulty making blood cells for a period of time
- Rare different types of cancer
- Rare, but brief swelling of the salivary glands
Any side effects that you would see with radiation therapy are possible with MIBG therapy too. There are several common side effects. The thyroid gland takes up iodine. It can work poorly or stop working altogether after I-131 treatment, even despite medications that we give to protect the thyroid gland from this. In patients who may have tumor cells inside their bones (a place called the bone marrow – where most of your blood cells are made), radiation in the bone marrow can cause it to make blood cells more slowly, making it very difficult for their bone marrow to recover as it would in other treatment options.
Since we aren’t the only ones doing this, what makes us special?
We treat the whole family– period. We don’t forget that the patient beneath the sheets is still a young child. Children receiving therapy with I-131 MIBG must remain in a special room for 3 to 5 days. As such these kids and their families have very special and very unique needs. Our team of physicians, nurses, psychologists, social workers, child life specialists, music therapists, radiation safety specialists, and administrators are experts at tailoring your child’s and family’s treatment experience to meet your unique needs. View images of our MIBG Room.
Is there an age requirement?
No. We match how we treat our patients to their level of maturity.
After deciding that I am interested in treatment with MIBG for my child what comes next?
We will review your child’s medical history, any x-ray and lab studies that have been done recently, and discuss your child’s case with your local medical team. In this way we can best determine if treatment with MIBG is the best option for your child, and if so, how to make your child’s experience here a successful one. This happens about 3-4 weeks before receiving the MIBG treatment. You and your child will also meet, face to face, with our entire team two weeks before treatment to ensure that all of your needs can be met and that your child can handle the many sometimes difficult aspects of MIBG treatment.
What happens during treatment?
Your child will be admitted the day before treatment to get used to the MIBG room and for our nurses to get to know him or her better. On the morning that MIBG is given, a urinary catheter will be placed to drain any urine that might contain radioactivity after the MIBG is given. This catheter will stay in place for approximately 3 – 4 days. Medicines to control nausea and to protect the thyroid gland will be started. I-131 MIBG will then be given through an IV over about two hours. Your child will be monitored very closely for side effects during and for several hours after the infusion. These would include some nausea as well as a temporary rise in blood pressure. He or she will remain in our special MIBG room for approximately 3 – 5 days while the radiation dose wears off.
Is staff in the room at this time?
There will be staff watching your child throughout the entire procedure. The staff will be in and out of the room during this time. The staff includes nurses, physicians, radiation safety specialists, and child life specialists.
Is the MIBG room designed to be like any other room or is it completely different?
This room is unique and meets specific safety standards to ensure the best care for the patient and their family, as well as ensure your safety and that of the team taking care of your child. The room is the size of 2 hospital rooms and includes a large room which serves as a “suite” for the parents. Around your child’s bed are placed several lead shields designed to protect you and your child’s team from any radiation that may be coming from your child during treatment. Everything the patient needs is in the room, even a private bathroom. The room is configured so that there’s ample room for nurses and other medical staff to work. The parents will be able to sleep in the attached suite. There is also audio/visual equipment that you can control from outside the room if you want to put in games or movies for your child or change the channel for them. There will be day and night time video monitoring and audio monitoring as well as two way communication between your sleeping area and your child’s room if there are concerns.