Radioactive Iodine Treatment

Radioactive Iodine (RAI) is often chosen for treatment of hyperthyroidism (overactive thyroid) because of its simplicity: it is given in a single dose. RAI also has minimal or no side effects.

How RAI works?

RAI is similar to the iodine found in foods such as fish, seaweed, and iodized salt, except that it releases an electron, or beta particle, which creates its therapeutic action. The treatment is based on the fact that the thyroid actively accumulates iodine, which it then uses to produce thyroid hormones required for normal bodily functions.

Given as a capsule or dissolved in water, the RAI is absorbed quickly by the stomach and intestines. It is then carried in the bloodstream to the thyroid and taken up by the gland. Here, the RAI disrupts the function of some of the thyroid cells – the more radioactive iodine, the more cells that cease to function. Excessive amounts of thyroid hormones are no longer produced and symptoms of hyperthyroidism begin to disappear.

Side Effects

RAI treatment has few side effects and these occur infrequently:

• Sore throat a few days following RAI treatment
• Swelling of salivary glands
• Mild nausea

Precautions

Some precautions are necessary in order to reduce the radiation families and friends are exposed to, because of the small amount of radiation that emanates from the neck where the RAI is stored for a few days following treatment.

1. Avoid prolonged contact with others, especially children and pregnant women: Always maintain a general distance of one arm’s length between the person treated and others who spend more than two hours next to the patient in any 24-hour period. This applies especially to children and pregnant women. While brief contact with a person after treatment is acceptable, sleeping together, watching television, going to movies, long care or plane trips should be avoided for approximately 11 days after the treatment.
2. Sharing food and utensils Sharing all food and utensils; including glasses, bottles, cans of drinks, water, beer, etc., should be avoided. E.g.: when the treated person is eating an ice cream cone, it should not be licked by anyone else. Dishes and eating utensils of the treated person should be rinsed adequately before being put with those of the rest of the family. Paper plates and plastic utensils should only be used if they are immediately disposed of outside the home. Cooking is fine, as long as the utensil used to taste the food while cooking is not re-used before rinsing.
3. Drink lots of liquids and flush twice: The treated person should drink large amounts of liquids, especially water, to help remove the RAI from the system. Always flush the toilet twice after using it, and be sure to thoroughly clean up any spilt urine. Laundry need not be washed separately unless the treated person has sweated heavily, such as after exercise.
4. No pregnancy or breast-feeding: It is extremely important that women who are breast-feeding stop before the RAI is given, since iodine is concentrated and excreted in breast milk. Pregnant women should not be treated with RAI, and pregnancy should be avoided for six months following treatment.