Radioiodine photo

Radioactive Iodine 131 (I-131)

Why will I receive radioiodine treatment? 
You will receive radioiodine because you and your doctor have agreed that this is the most appropriate treatment for your thyroid cancer. Special precautions will be taken to protect you and the hospital staff caring for you, to prevent or limit the amount of exposure to a radioactive source.  You may have some concerns about feeling isolated or alone during this procedure. This handout will tell you about the special precautions that you and the hospital staff must use during your treatment. It will also give you some instructions to follow when you go home.

Why do I need special care?
Iodine-131 (I-131) is radioactive. Radiation can be measured around your body and I-131 is present in your skin oil and sweat. Whatever touches your skin will pick up a small amount of radiation.  The I-131 leaves your body through your urine primarily. Small amounts of I-131 may also leave through your saliva, sweat and feces. The amount of radioiodine remaining in your thyroid tissue is responsible for the desired medical effect. Radioiodine disappears by itself over a period of time.

How does radioiondine work?
Radioiodine is collected by the thyroid gland. The radiation given off by this form of iodine decreases the function of the thyroid cells and inhibits their ability to grow. This is the desired medical effect of this treatment. Some of the other tissues in your body will receive some incidental radiation. This small amount of radiation has NOT been shown to produce any adverse effect.

How long does radioiodine stay in your body?
The radioiodine from your treatment will remain in your body temporarily.  Most of the radioiodine not collected by your residual thyroid tissue will be eliminated during the first two days after your treatment. The amount that remains in your thyroid tissue is responsible for the desired medical effect. A radiation safety specialist will come to your room one to two times a day to measure your radiation levels. These radiation levels will be less everyday. On discharge from the hospital, a minimal amount of radiation remains in your body and will go away over the next several weeks.

Where will I stay when I have my iodine therapy?
You may be admitted to the hospital. If this is necessary, you will be in a private room with a private bathroom. Special precautions are taken to protect you and the hospital staff caring for you. Most patients, however, are able to return home immediately after administration of the iodine, and will need to follow specific radiation safety precautions at home.

If you are admitted to the hospital, your room will have a protective covering on the floor. There will also be plastic covers on some of the furniture, door handles, light switch, telephone and TV remote. This is to protect others who will use the room after you, and facilitate cleanup. While you are in this special room you will be allowed visitors only for a short time period. You can call your family and friends on the telephone. 

If you are treated as an outpatient, family members should not come closer than six feet from you the first day and three feet the second day. Further precautions will most likely not be necessary after this, but this will be determined by the radiation safety specialists with a specific measurement. At home, please cover items that are frequently shared, such as a TV remote control or computer keyboard or wear disposable gloves.

Your doctors and nurses will come into your room to take care of you. The staff will always be available to you to assist you whenever needed. However, the staff will spend as little time as possible in your room. This will help to limit the staff's exposure to radiation.

How can I reduce radiation exposure to others?

There are three basic principles to remember:

  1. Distance: The greater the distance you are from others, the less radiation they will receive. Try not to remain in close contact with others for longer than is necessary.
  2. Time: Radiation exposure to others depends on how long you remain close to them. You should try to minimize the time spent in close contact with others.
  3. Hygiene: good hygiene minimizes the possibility that other people will be contaminated with the radioiodine that leaves your body. Since most of the radioiodine leaves your body in your urine, good toilet hygiene and careful, thorough washing of your hands will reduce the possibility of contamination.

How do I apply these principles?

In the hospital:

  • Meals will be served on disposable plates with disposable utensils.
  • All trash and linens should be placed in the appropriate receptacles in your room.
  • Flush the toilet three times after you use it.
  • If you feel like you are going to vomit, try to go into the bathroom. Vomit into the toilet. Call your nurse right away.
  • Plan to wear a hospital gown and slippers as you will be confined to your room. Do not bring a suitcase full of personal items.  Anything that is taken into your room will need to be checked by the radiation safety office before it can be removed. This is to keep the radioactive material from going into public areas. Some items may need to be retained if they absorb too much radioactivity from perspiration.

At home:  
Observe the following recommendations for the first week you are home. You can always check with your doctor if you have any questions.

  • Sleep alone for the first few (3 - 4) days. Avoid kissing or sexual intercourse for three to four days after treatment. Do not sleep together for an entire night until a week after treatment.
  • Avoid prolonged physical contact, particularly with children and pregnant women; limit to 15 minutes. Do not resume care of an infant or breastfeeding until your doctor tells you that you can. Stay 3 to 6 feet away from other people, except when contact is necessary.
  • Do not prepare or serve food to other people. Do not wash, dry and put away dishes without using vinyl gloves. Wash your hands with soap and plenty of water each time after you go to the toilet.