Iodine-131

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. 

Benefits of the Treatment

I-131 therapy is a radioactive medication. It has been shown to be an effective treatment for thyroid abnormalities.

Preparing for the Procedure

• 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.

Post Procedure

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.

Side effects of I-131 therapy

Some patients may feel discomfort in the neck, face or gastric for a few days.

Post Procedure

• 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

For more enquiries or to make an appointment, call  (65) 6705 2777. 
 

Reference: 
1. The SNM Practice Guideline for Therapy of Thyroid Disease with 131I 3.0*
2. Journal of Nuclear Medicine, published on Jul 11, 2012