Radioactive iodine therapy

Radioactive iodine also called radio iodine is an important radioisotopes of iodine discovered in 1938.It has a radioactive decay half-life of about eight days.

There are two radioactive isotopes that are commonly used in patients with thyroid diseases: I-123 (harmless to thyroid cells) and I-131 (destroys thyroid cells).

Radioactive iodine is associated with nuclear energy, medical diagnostic and treatment procedures, and natural gas production. It also plays a major role as a thyroid gland therapy because Iodine in food is absorbed by the body and preferentially concentrated in the thyroid where it is needed for the functioning of that gland.

Radioactive iodine, given in a capsule or liquid form, is absorbed and concentrated by the thyroid gland. 

While radiation can cause thyroid cancer, treatment of hyperthyroidism with radioactive iodine does not increase your chances of getting thyroid cancer, because the radioactive iodine passes out of your body in your urine and saliva within days depending on the dose you received and your age.

 Most people don't feel different after treatment. But a few people may feel a little nauseated.

Radioactive iodine therapy destroys any remaining thyroid tissue or cancer cells that were not removed during surgery.

Persons take radioactive iodine, must follow doctor's instructions to avoid exposing other people to radioactivity. The amount of radiation exposure markedly decreases as the distance from the patient increases. Patients who need to travel in the days after radioactive iodine (I-131) treatment are advised to carry a letter of explanation from their physician. This is because radiation detection devices used at airports or in federal buildings may pick up even very small radiation levels. Details should be discussed with a physician prior to, and at the time of, the radioactive iodine treatment.

A common treatment method for preventing iodine-131 exposure is by saturating the thyroid with regular, non-radioactive iodine-127, as an iodide salt.

The thyroid will absorb very little of the radioactive iodine-131 after it is saturated with non-radioactive iodide, thereby avoiding the radiation from radioiodine.

Side effects of radioactive iodine;

·        Dry mouth sometimes occurs.

·        Tenderness in your neck area.

·        Temporary or permanent decreases in blood cell counts.

·        Fatigue.

·        Sore throat.

·        Swelling and tenderness of the salivary glands.

·        Taste changes.

Radioactive iodine is safe to use in individuals who have had allergic reactions to seafood or X-ray contrast agents, since the reaction is to the compound containing iodine, not the iodine itself.

Most doctors also recommend that the patient follow a low iodine diet for 1 or 2 weeks before treatment. This means avoiding foods that contain iodized salt and red dye #3, as well as dairy products, eggs, seafood, and soy.

( Scheme of the thyroid gland. (Photo credit: Wikipedia)