What is Iodine-131 (I-131) Therapy?
Iodine-131 (I-131) is a form of radioiodine that has been used in radiation therapy to treat thyroid conditions such as hyperthyroidism and thyroid cancer. It is an effective and safe therapy in which radioactive Iodine-131 capsules are swallowed and absorbed into the bloodstream, to destroy thyroid gland cells.
I-131 therapy is an outpatient treatment and no hospital stay is required. It is administered orally in the procedure room at the Nuclear Medicine Suite.
A pre-treatment consultation with a nuclear medicine physician is necessary, during which patients will be briefed on the procedure and treatment dosage.
What are the benefits of Iodine-131 Therapy?
I-131 therapy is a radioactive medication. It has been shown to be an effective treatment for thyroid abnormalities. Here are the main benefits of Iodine-131 therapy:
- Highly targeted treatment: The thyroid naturally absorbs iodine, so Iodine-131 specifically concentrates in thyroid tissue. This allows for precise treatment of thyroid cells while minimizing effects on the rest of the body.
- Effective for Hyperthyroidism: Often used to cure or significantly reduces symptoms of conditions like Graves’ disease or toxic nodular goiter. It helps normalize thyroid hormone levels when other treatments (like medications) are not effective or cause side effects.
- Key Role in Thyroid Cancer Management: Used after thyroid surgery to destroy any remaining thyroid tissue or microscopic cancer cells. This reduces the risk of recurrence and helps improve long-term survival.
- Non-invasive and Convenient: Given as a capsule or liquid, making it easier and less invasive compared to surgery. It typically requires only one treatment, though some patients may need repeat doses.
What happens before Iodine-131 (I-131) Therapy?
- Some medications, food and examinations should be abstained before the treatment, as they can impede iodine take up by the thyroid gland and render the treatment ineffective. Please contact your doctor or Farrer Park Hospital’s Nuclear Medicine Suite to find out more
- You are required to fast for two hours prior to I-131 administration and at least one hour after the dosage has been administered (small quantity of water is allowed)
- Iodinated contrast media during CT scan/Angiogram/IVU, should not be done four weeks prior to the therapy.
What happens after Iodine-131 (I-131) Therapy?
I-131 that has not been taken up by the thyroid will be excreted from the body within a week. This will be done primarily through the urine, but very small amounts may still be present in the saliva, sweat and fecal matter.
Please contact your doctor or Farrer Park Hospital’s Nuclear Medicine Suite if you have further queries.
What are the side effects of Iodine-131 (I-131) Therapy?
Some patients may feel discomfort in the neck, face or gastric for a few days.
What should you do after Iodine-131 (I-131) Therapy?
- Avoid prolonged close contact (at least six feet distance) with pregnant women and young children under the age of five, for at least one week after treatment
- Drink plenty of water after the treatment
- Do not share cups, glasses, plates or other utensils with anyone (including family members) for at least two days
- Practice good personal hygiene and flush the toilet bowl twice after each use. Avoid splashing while urinating to prevent contamination
- Contraception is strongly recommended for at least four months after treatment
- Do not breastfeed your child until the next pregnancy, otherwise stated by your doctor
- Sleep alone in a dedicated room for at least five days
Should you feel unwell after the procedure, contact your doctor immediately or call our 24-HR Medical Urgency Clinic at (65) 6705 2999.
