Iodine is an essential mineral which can be found in our normal daily diet. Iodine is taken up by the thyroid gland because it is an essential element in the normal production of thyroid hormone. Radioiodine (I-131) is a radioactive form of iodine, which has been safely used as an oral medication since the 1960s in both benign (thyrotoxicosis) and malignant thyroid conditions. When radioiodine is swallowed, it is absorbed into the bloodstream and concentrated by the thyroid gland (and differentiated thyroid cancer), where it begins destroying the cells.
Radioiodine is usually taken orally in the form of a capsule that is tasteless and odourless. Your attending Nuclear Medicine doctor will decide on the dosage of radioiodine for your treatment, based on your medical condition. For thyroid cancer, depending on the amount of radioiodine prescribed, you may be admitted to hospital.
Your Nuclear Medicine doctor will need to prepare your body to absorb the radioiodine and require you to stop or take some medication.
You need to avoid iodine-rich food as instructed, as the consumption of such foods may reduce the effectiveness of our therapy.
For female patients, please ensure that you are not pregnant, as the radiation from radioiodine therapy may be harmful to the developing fetus during pregnancy. Please inform your doctor if you are breast feeding.
Avoid crowded places (especially close and prolonged contact with pregnant women and children less than 5 years old) as instructed by your Nuclear Medicine doctor.
You will be advised by the doctor whether to continue anti-thyroid medication (for hyperthyroidism) or to start thyroid hormone after the treatment.
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If you are suspected to have thyrotoxicosis, blood tests and ultrasound or radionuclide thyroid scan may be requested by your doctor.
If you are suspected to have thyroid cancer, a biopsy of the thyroid may be required for the diagnosis. Read about the diagnosis for here >