Iodine treatment for thyroid cancer uses radioactive iodine to specifically target thyroid cells. It can be very effective in treating certain types of thyroid cancer, but there are some risks to consider.

Thyroid cancer is a cancer that develops in the thyroid gland. Your thyroid is a butterfly-shaped gland in your neck. It produces the hormones that control important bodily functions, such as temperature, heart rate, and metabolism.

Thyroid cancer is often very treatable with surgery, radiation, and chemotherapy. A unique treatment option for thyroid cancer is iodine treatment. It combines iodine with high doses of radiation to deliver radiation directly to your thyroid gland, killing cancer cells.

The thyroid gland absorbs any iodine that enters your body. Radioactive iodine treatment uses iodine that contains high doses of radiation. Your thyroid gland absorbs the iodine, and the radiation destroys cancer cells and other thyroid cells.

Since your thyroid gland absorbs the iodine, the radiation has only minor effects on the rest of your body.

This treatment is used to destroy any thyroid cancer that’s not removed during surgery, or any cancer that has spread into the neck and lymph nodes.

In recent years, radioactive iodine treatment has become part of the standard treatment for papillary and follicular thyroid cancers that have begun to spread.

It’s not typically used for early stage thyroid cancers. Small thyroid tumors can often be completely removed with surgery, making further treatment unnecessary.

For iodine treatment to be most effective, doctors recommend boosting your levels of thyroid stimulating hormone (TSH) before you start.

If your thyroid gland has been removed, you can raise your TSH levels by doing the following:

  • Stop taking any thyroid hormone pills for a few weeks before treatment. This will result in low thyroid levels, triggering your pituitary gland to release more TSH. The condition will be temporary, but you might experience symptoms such as weight gain, fatigue, muscle aches, constipation, and depression.
  • Get an injection of thyrotropin. It can make withholding thyroid hormone for a long period unnecessary. This drug is given for 2 days, with iodine treatment starting on the third day.
  • Following a low iodine diet for 1 or 2 weeks before treatment. This means avoiding foods with iodized salt and red dye #3, as well as seafood, eggs, soy, and dairy.

Typically, only one round of iodine treatment is needed. Treatment typically takes place in the radiology unit of a hospital or other medical facility.

Many people receive iodine radiation treatment as an outpatient procedure. They are able to go home on the same day. However, if you receive a very high dose, you might need to stay in the hospital overnight.

Your iodine treatment itself can be in capsule or liquid form. Often, only a single treatment is needed.

For all forms of iodine treatment, anyone who came with you to your appointment, or who is visiting you at the hospital, will be asked to leave the room. This is done to prevent exposing the person to unnecessary radiation.

After treatment

Following treatment, your body will be radioactive. To not affect others, it is important to isolate yourself for the first few days.

Immediately after treatment, healthcare professionals will measure the radiation levels in your body. They will ask you to stay in the treatment room for at least 1 to 2 hours. You won’t be able to have any visitors at this time. However, you can read, use any devices you have with you, like a tablet or phone, watch television, or nap.

If your treatment is done as an outpatient procedure, you can go home after this 1- to 2-hour window passes. Before you leave, you’ll make an appointment for a follow-up nuclear scan within 3 to 5 days.

It’s important to either drive yourself home or to have a ride arranged. You can’t take any form of public transportation on the day of your iodine treatment.

Once you’re home, drink plenty of liquid for the next few days. This will help your body excrete any remaining radiation through your urine, sweat, and bowel movements.

It’s best to urinate and move your bowels quickly every time you feel the urge to clear radiation from your system.

Thyroid cancer treatment

There are many treatment options for thyroid cancer in addition to iodine radiation therapy. These include:

  • Surgery: Surgery to remove the thyroid tumor, the entire thyroid, and any affected lymph nodes is often the first step in treatment.
  • Radiation: Radiation is used to kill cancer cells and shrink tumors.
  • Chemotherapy: Chemotherapy helps stop the spread of cancer and kills cancer cells.
  • Hormone therapy: If the thyroid gland has been removed, high doses of thyroid hormone (levothyroxine) can help keep TSH levels low, possibly slowing the growth of cancer cells.
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Iodine treatment is an effective treatment for thyroid cancer. However, there are known risks. The risks associated with this treatment include:

Rarely, more serious side effects can occur, such as male fertility issues and a slightly increased risk of certain cancers. Cancers that have been linked to iodine radiation treatment in very cases include:

The prognosis, or outlook, for thyroid cancer is typically positive.

Thyroid cancer is highly treatable. Many common forms have survival rates of nearly 100% when detected early. The stage at diagnosis and type of thyroid cancer can affect your outlook.

Iodine radiation treatment is a standard treatment for thyroid cancers that can’t be completely removed with surgery.

Radioactive iodine is absorbed by the thyroid gland, allowing for the delivery of high doses of radiation without harm to the rest of the body.

Most people only need one round of iodine treatment. Radioactive iodine can be taken as a capsule, liquid, or injection. Treatments can often be done on an outpatient basis.

After treatment, you’ll need to be isolated for a few hours, and your body will continue to expel radiation for a few days. You’ll need to avoid crowded places and direct contact with others during this time.