Radioiodine I-131 for Diagnosing and Treatment of Thyroid Diseases

Abstract

Iodine is essential for proper function of the thyroid gland, which uses it to make the thyroid hormones. The thyroid is equipped with an active system called “Na+ /Ithyroid symporter pump” for moving iodine into its cells. Because the ability of thyroid cells to take up radioiodine I-131 or RAI exactly like iodine, it has been used by medical professionals to diagnose and treat various thyroid diseases. RAI that is not concentrated in the thyroid gland is eliminated from the body through sweat and urine. However, I -131 has unique beta and gamma emitting properties with a half-life of about eight days; the beta radiation can be used in high dose for destruction of thyroid nodules and for elimination of remaining thyroid tissue after surgery for the treatment of Grave's disease and differentiate thyroid cancer, and the gamma radiation allows for imaging and uptake measurement.