Radioactive iodine treatment

Radioactive iodine is a medicine that you take one time. After you swallow it, it is taken up by your thyroid gland. Depending on the dosage used, the radioactivity in the iodine destroys most or all of the tissue in your thyroid gland, but it does not harm any other parts of your body.

While radiation can cause thyroid cancer, treatment of hyperthyroidism with radioactive iodine does not increase your chances of getting thyroid cancer.

Radioactive iodine treatment has been safely used on millions of people for more than 60 years.

Radioactive iodine may be used to treat hyperthyroidism in people who have noncancerous (benign) thyroid nodules that make too much thyroid hormone.

Radioactive iodine is also used if you have your thyroid removed (thyroidectomy) because of thyroid cancer. Radioactive iodine therapy destroys any remaining thyroid tissue or cancer cells that were not removed during surgery.

In almost all cases, your thyroid hormone levels will return to normal or below normal after radioactive iodine treatment. This may take 8 to 12 weeks or longer. If your thyroid hormone level does not go down after 6 months, you may need another dose of radioactive iodine.

If you have thyroid cancer and you are treated with radioactive iodine, it may take from several weeks to many months for your body to get rid of any remaining cancer cells.

Your thyroid nodule is unlikely to grow after being treated with radioactive iodine.

General recommendations

• For a period of time, you will need to keep your distance from other people, especially young children and pregnant women.
• Avoid close contact, kissing, and sexual activity. You may need to sleep in a separate bed from your partner.
• Keep the toilet very clean. Men should urinate sitting down to avoid splashing. Flush the toilet 2 or 3 times after each use. Wash your hands well with soap and lots of water each time you use the toilet.
• Rinse the bathroom sink and tub well after you use them.
• Use separate towels, washcloths, and sheets. Wash these and your personal clothing by themselves. Don't wash them with other people's laundry.
• You may want to use a special plastic trash bag for all your trash, such as bandages, paper or plastic dishes, menstrual pads, tissues, or paper towels. Talk to your treatment facility to see if they will handle the disposal. Or after 80 days, this bag can be thrown out with your other trash.
• Wash your dishes in a dishwasher or by hand. If you use disposable dishes, they must be thrown away in the special plastic trash bag.
• Don't cook for other people. If you must cook, use plastic gloves. Then throw them away in the special plastic trash bag. Don't share cups, dishes, or utensils.

Pregnancy and children

• Your doctor will tell you when it is safe to have sex and become pregnant.
• You should not breastfeed your baby after you have been treated with radioactive iodine. Ask your doctor when it's safe to breastfeed.

Travel

• Don't take public transportation. If you are able, it's best to drive yourself.
• It is important to prepare for any problems you may have at airport security. People who have had radioactive iodine treatment can set off the radiation detection machines in airports for a week to 10 days. Check with local authorities about any steps or permission you may need to travel.
• If you plan to travel on the interstate, you may set off radiation detectors. Most police and transportation workers are aware of medical radiation, but it may help to carry some paperwork from your doctor.