Low Dose Radio-iodine
Therapy for
Thyrotoxicosis

What is Radio-iodine?

Iodine is a natural element found in food. Iodine from the food consumed concentrates in the thyroid gland. Radio-iodine (I131) is a special form of iodine that emits radiation. This radiation is useful in treating the overactive thyroid gland.

What is a Thyroid gland?

Thyroid is a gland that produces hormones which is responsible in regulating all the body functions. Thyroid hormones affect heart rate, skin, bowel activity, brain and other organs. The thyroid gland is situated in front of the wind pipe in the neck.

What is Thyrotoxicosis?

Thyrotoxicosis is a condition where the body produces too much thyroxine (T4) and triiodothyronine (T3), the thyroid hormones. The healthy thyroid gland is small and cannot be felt. When overactive the thyroid is often enlarged and is called goitre. There are many types of thyrotoxicosis, the most common is Graves' Disease. Graves' disease is a condition where the immune system produces an antibody that stimulates the thyroid to produce too much thyroid hormone.

Why do I need Low Dose Radio-iodine Therapy?

You have a condition called thyrotoxicosis. This means your thyroid gland is overactive, producing too much thyroid hormone. Symptoms of an overactive thyroid include tremor, excessive sweating, palpitations and weight loss. Some patients have no symptoms, but if it is not properly treated, your health may be affected in the future. Radio-iodine therapy is a permanent way to resolve thyrotoxicosis. It is also used to shrink goiter.

How does Radio-iodine Therapy work?

Radio-iodine concentrates in the thyroid gland in the same way as normal iodine, and works by attacking and destroying the overactive thyroid tissue. The small dose of radiation stops it from producing excessive thyroid hormones.

Is Radio-iodine Therapy dangerous?

No. The amount of radiation used is small and does not cause cancer. This type of therapy has been used all over the world for about seventy years and is a well accepted and effective way of managing an overactive or enlarged thyroid gland.

What should I do before receiving Low Dose Radio-iodine Therapy?

An iodine-rich diet reduces the effectiveness of treatment as the iodine in the food competes with the radio-iodine to concentrate in the thyroid gland. Maintain a low iodine diet for 1 week prior to treatment with radio-iodine.
If you are female of childbearing age make sure you are not pregnant.
You will need to discontinue your thyroid medications such as Propylthiouracil or Carbimazole for about one week before and after the therapy (the exact duration will be determined by your endocrinologist).

How is Low dose Radio-iodine Therapy given?

Your endocrinologist will fix an appointment on your behalf. Food should not be ingested in the two hours before therapy. Radio-iodine will be administered to you orally either in the form of colorless liquid or tasteless capsule along with some water to drink. You will be asked to rest in the room for 1 hour after the treatment. Do not eat or drink anything during this time. This will help your body to absorb radio-iodine more quickly.

Will I feel ill afterwards?

No. Most patients have no side effects from the treatment. Occasionally, there is a mild ache in the neck area for a few days.

What are the precautions to be taken after Low Dose Radio-iodine Therapy?

After treatment with radio-iodine, most of the iodine will leave the body through natural excretion processes. Hence it is important that you keep yourself well hydrated. However, some of the iodine will stay inside your body, which means that you in turn can irradiate other people who are physically close to you.
IT IS YOUR RESPONSIBILITY TO PROTECT RELATIVES, FRIENDS COLEAGUES AND OTHERS FROM UNNECESSARY RADIATION THAT YOU ARE EMITTING.

The following are the list of precautions to be taken for 7 days post therapy:

Avoid prolonged contact with others especially pregnant and small children. Keep 2 meters distance.
Sleep alone.
Avoid immediate return to work especially if your job involves proximity with other people.
Avoid going to crowded places and public transport.
Flush the toilet twice after use.
Maintain personal hygiene and immediately clean up if there is any spillage of bodily fluids.
Wash utensils and clothes separately.
Stop breast feeding completely post therapy as radio-iodine is excreted through breast milk.
Avoid pregnancy or fathering children for 6 months post therapy.