I-131 MIBG is an iodine-based specialized pharmaceutical drug. The drug contains a form of radioactive iodine called “I-131” and “Meta Iodo Benzyl Guanidine (MIBG)”.
It is a neurotransmitter-like substance that is absorbed by neuroendocrine cells.
When I-131 MIBG accumulates within a tumor, it emits radiation that kills cancer cells.
Iodine-131 Meta-Iodo-Benzyl-Guanidine (I-131 MIBG) is a radiopharmaceutical that is used to diagnose and treat neuroendocrine tumors, a cancerous tumor that develops in the nerve tissue of newborns and toddlers.
Neuroblastomas, paragangliomas, and pheochromocytomas are all neuroendocrine tumors that can be treated using I-131 MIBG.
What is MIBG?
MIBG (Meta-Iodo-Benzyl-Guanidine) is a drug that was first used to treat high blood pressure. It was revealed by neural crest cells, which give rise to portions of your adrenal glands among other things.
Neuroblastoma is a form of cancer that arises from neural crest cells. Neuroblastomas belong to a group of tumors known as neurons-endocrine tumors, which are capable of absorbing MIBG and responding to therapy with it.
MIBG in combination with a larger dose of radioactive iodine is used to treat neuroblastoma. Absorbed by neuroblastoma cells, and it is radioactive enough to destroy them. This treatment is frequently successful in children because it has minimal side effects than other cancer treatments and targets neuroblastoma cells precisely.
How Does The Treatment Work?
A Nuclear Medicine Therapy professional monitors the administration of I-131 MIBG. It’s a procedure that takes place in a hospital.
The radiopharmaceutical is injected into the patient’s system via the bloodstream, and the patient is admitted to the hospital for a few days during and after treatment until the radioactivity in their body has reduced to a safe level for individuals to be around other people.
The radiation that is not absorbed by the cancer cells is excreted by the child’s body through urine. After receiving an I-131 MIBG dose, the patient’s body takes two to five days to reach safe radiation levels. The duration of treatment is regulated by the dose of I-131 MIBG administered, the size of the tumour being treated, and the patient’s kidney function.
How is I-131 MIBG Therapy Administered?
- The administration of I-131 MIBG Therapy is done by following steps:
- The patient is admitted to a special room called the Nuclear Medicine Therapy Room or the Radioisotope Therapy Isolation Room on the day of the therapy.
- The I-131 MIBG is administered over 3 to 4 hours through an IV canula or central venous catheter. Additionally, IV fluids for hydration and other drugs may be administered as necessary.
- The majority of I-131 MIBG accumulates in neuroblastoma cells, and the remaining will be eliminated via the urine. As this urine is radioactive, additional precautions are needed.
- Other biological wastes, such as saliva, are also radioactive. This exposes everyone in the proximity of the patient to radiation.
- Check with your doctor for any precautions or safety measures that may be necessary.
A Customized Isolation Room For Radioisotope Therapy:-
- The patient is admitted to a dedicated high-dose radioisotope therapy isolation room because the caregivers and those attending the patient undergoing the I-131 MIBG Therapy are vulnerable to radiation exposure.
- The isolation room is a custom-built chamber with lead-lined walls and floors. The use of lead decreases the risk of radiation exposure.
- Portable lead sheets are also used to surround the patient’s bed. Caregivers are supposed to remain behind these lead shields throughout all circumstances.
- Urine and other bodily wastes from the patient are similarly radioactive. These discharges are dumped through lead-lined pipes and deposited in a specially constructed deterioration tank that is submerged underground and stored until it is safe to release them into the drains.
- The garbage cans are similarly coated with lead. Soiled linen, diapers, and other garbage are collected daily and transferred to a specialized waste storage facility, where it is kept for three months before being disposed of as normal medical waste.
On a daily basis, a Radiation Safety Officer is responsible for monitoring the radiation levels.
Side Effects of I-131 MIGB Therapy
- The majority of children do not become ill as a result of MIBG treatment and tolerate it well. However, there may be adverse effects, such as:
- The number of red and white blood cells, as well as platelets, produced in the bone marrow decreases. Blood and platelet transfusions may be required, as well as stem cell infusions occasionally.
- Thyroid Gland Function Inhibited
- Tiredness, Weight Gain, and Constipation
- Nausea and Vomiting
- Dry Mouth
- Salivary Gland Irritation
- High Blood Pressure or Low Blood Pressure
- Thinning of Hair
- Bleeding due to low Platelets count
- Infection & Fatigue due to low Red and White Blood Cells
- Loss of Appetite
- Breathing problem due to Infection or lung damage (overactive thyroid gland)
- The child patient receives an injection of bone marrow cells that were obtained prior to MIBG therapy a few weeks following treatment.
Role of Parents Before and After Therapy
Parents will need to play an essential role in providing day-to-day care and assistance as a primary caregiver:
- Assisting the youngster with showering and other hygienic requirements, such as teeth brushing.
- Giving the child all of his or her oral medicine on time
- Supporting the child with his or her bathroom needs.
- The team of doctors and radiation safety professionals will work closely with the parents to assist them in caring for their child.
- At home, your child’s radiation will be reduced but not removed completely. For another week, parents must follow the healthcare team’s advice for being safe around it.
- The healthcare team will discuss with you where your child should sleep and go to the bathroom, as well as who can be in close proximity to your child.
When Can Child Go Home?
Children who receive I-131 MIBG Therapy are typically admitted to the hospital for three to five days, and often longer, until their radiation numbers decrease below a certain limit.
A Radiation Safety Officer (RSO) is assigned to the centre and is in charge of monitoring the radiation levels on a daily basis.
Even if the radiation levels are reduced to a safe level, the child will still have a small amount of radioactivity in his or her body, mandating some simple home safety precautions.
The RSO will give detailed discharge instructions on how to stay safe from radiation at home.
What are the Next Follow-Up Steps After Discharge?
- Following discharge, caregivers must ensure that the kid continues to take the Thyroid Protecting Agent (Lugols Solution) for four weeks as prescribed.
- When the child gets home, a Complete Blood Count (CBC) will be required at least twice a week.
- For a few weeks after the therapy, the youngster will almost certainly require platelet and red blood cell transfusion.
- 9 to 12 weeks after therapy, a follow-up MIBG Scan must be performed.
Conclusion
It’s the first FDA-approved radiopharmaceutical for the treatment of paragangliomas and pheochromocytomas in patients aged 12 and above who have tumors that can’t be removed surgically and have migrated to other parts of the body.
MIBG Therapy (high-dose iodine) is a new type of treatment for resistant high-risk advanced neuroblastoma, a malignant tumor that starts in the nerve tissue of newborns and young children.
