Radioiodine is a radioactive form of iodine. Iodine is part of each of our diets and is needed for the thyroid gland to work normally.
The thyroid gland controls the speed (metabolic rate) at which our body works.
Like ordinary iodine, radioiodine is taken up by any thyroid cells left after your thyroid operation. The radioactive form of iodine is used to destroy any remaining thyroid cells.
The doctor will discuss different treatment options with you when you attend your out-patient appointment. You can ask any questions you have. We will ask you to sign a consent form if you decide you want the treatment.
If you are advised to have radioiodine therapy you will need to be admitted to the isotope cubicle.
This is a single room with a bathroom on the Princess Margaret Ward. This room has been specially adapted because of the high dose of radiation involved in the treatment. The treatment dose of radioiodine is usually given as a capsule.
Many patients do not experience any side effects with radioiodine. However the following side effects can occur;
I have been told I will need to stop my thyroid tablets before my radioiodine, why is this?
Thyroid hormone tablets interfere with the radioiodine treatment. We will ask you to stop taking these tablets before and during your treatment to make sure the thyroid cells left in your body take up the radioiodine. These tablets include T4 (thyroxine) and T3 (Tri-iodothyronine).
You may feel tired or weak when not taking these tablets. This is normal and the effects will disappear once you start taking them again. Some people may also notice some of the following: dry skin, low mood, tearfulness, constipation, feeling cold, loss of appetite
You will usually start taking your tablets again on the day you leave the ward.
We encourage you to drink plenty of fluids, as this will help clear the radioactivity from your body more quickly. The doctor will ask you to cut down on certain foods that contain iodine for 7 days before you receive your radioiodine. Your doctor will discuss this with you in clinic. We will give you a diet sheet to help.
You will be seen by the ward doctor, a nurse and a physicist. They will take some details from you, then take you to the isotope cubicle. The physicist will come to the cubicle and give you the radioiodine treatment capsule.
After an hour the physicist will come back to the cubicle to measure the level of radiation inside of you. We will ask you to lie on the bed while a special monitor inside the cubicle does the measurement. This will be repeated each day. The measurement does not hurt you and does not take long.
Most people are in hospital for 2-4 days. Whilst you are in the cubicle we will ask you to drink as much as possible. This helps flush the remaining radioactivity out of your body. Once the radioactivity level in your body is low enough you will be able to go home.
Does anything else need to be done before I go home?
Before you go home you will be taken to the Nuclear Medicine department for a scan. We will ask you to shower and change into some clothing that you have not worn during your stay in the cubicle.
The scan is in 2 parts. Each part takes about 30 minutes and looks at where the radioiodine has gone into your body. You have to follow some instructions after leaving hospital, but we will explain these to you.
You need to wash it separately from everyone else’s when you go home or leave it in the cubicle for us to dispose of for you.
You can have visitors but unfortunately children, pregnant women or breast-feeding women cannot visit you whilst in the isolation cubicle.
Other visitors will not be allowed to come into your cubicle but you can speak to them via a phone in your room and another in the corridor. You will be able to see each other through a special window whilst you are talking. All visitors must speak to the ward staff before they visit.
You should also bring enough money to pay for any newspapers or phone calls you may wish to make. The money for any newspapers will be collected before you go into the cubicle.
You can take money into the isotope cubicle for any phone calls you might wish to make. There is a telephone in your room which will take incoming calls. We will give you the extension number when you come in. Your family and friends will be able to contact you via the main switchboard on 029 2061 5888 then ask for your extension number.
You can take a mobile phone into the isotope cubicle. You will need to put it inside a plastic bag before using it in the cubicle.
As well as the usual furniture, the isotope cubicle has the following facilities:
Please do not bring your own electrical items into the hospital if possible. This is because we have to check them for safety.
No. We will ask if you are pregnant before we give you the radioiodine capsule. If there is any doubt then we will ask you to take a pregnancy test.
You will need to avoid becoming pregnant for 6 months after your radioiodine treatment.
No. You will need to stop breast-feeding before we can give you the treatment.
You will be advised to avoid fathering a child for 4 months after your treatment.
We try and keep unnecessary radiation exposure to others to a minimum. We will advise you on how to achieve this with your family and friends.
Staff will not stay with you for any longer than is necessary to attend to your needs. We will wear gloves and other special clothing if we have to come into your room whilst you are in hospital.
You will have a clinic appointment a few weeks after your treatment. The doctor will discuss the scan that you had whilst you were an in-patient.
Some patients will need further treatment doses of radioactive iodine. The doctor will discuss any need for more treatment with you in out-patients.
8-12 months after your treatment, your doctor may ask you to visit the Nuclear Medicine department as an out-patient.
On the selected Monday, you will have a blood test. The physicist from the Nuclear Medicine department will then give you the radioiodine capsule in the department. The amount of radioiodine we give you is much less than the amount you received for your treatment. We will explain everything to you and will also give you a letter explaining the things you need to do afterwards.
We usually ask you to come back to the Nuclear Medicine department 3 days later. At this visit you will have a scan and we will measure the amount of radioactivity in the area of the thyroid gland. This simply involves you lying down on a bed for the scan and sitting on a chair for the neck measurement.
The doctor will ring you when he or she has seen the results. The doctor will then decide whether you need to have further radioiodine treatment as an in-patient. If this is recommended, we will usually ask you to come into hospital the following week.
We hope you have found this leaflet helpful. If you have any questions or want further information, please phone the Nuclear Medicine department on 029 2031 6237 or 029 2031 6238.
Velindre Cancer Centre,
Velindre Road, Whitchurch, Cardiff, CF14 2TL
This leaflet was written by health professionals. The information contained in this leaflet is evidence based. It is reviewed and updated every 2 years.
Written December 2003
Reviewed November 2012