Thyrotoxicosis occurs when the thyroid gland produces too much thyroid hormone.
Radioiodine treatment uses a form of iodine that is radioactive. The iodine is taken up by the thyroid gland and the radioactivity 'slows down' the thyroid's production of certain hormones.
Your doctor will have explained that there are different types of treatment for thyrotoxicosis. Radioiodine has been suggested as a suitable treatment for you.
Most of the radioiodine will go to your thyroid. The rest will pass from your body in your urine.
The radioiodine is normally given in the form of a capsule. If you cannot swallow capsules, then it may be possible to arrange for you to have the radioiodine in the form of a small drink.
No, you should feel no immediate after-effects except possibly a slightly sore throat.
If your tablets are for controlling your thyrotoxicosis, then you may need to stop these for some time. You will be told how long to stop them for by your hospital doctor during your clinic visit or in your appointment letter before your treatment. Otherwise there should be no need to stop any other tablets.
No. We will ask women aged between 12 and 55 years of age if there is any possibility you may be 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 stop breast-feeding before we can give you the treatment.
50 years experience of using radioiodine has shown no effect on the health of children of patients who have had this treatment. However, female patients should avoid pregnancy for at least 6 months after radioiodine treatment. Male patients will be asked to avoid fathering children for four months after radioiodine treatment.
You will probably need to take some time off work. This will depend on the amount of radioiodine you receive and, possibly, on the type of work you do.
For example if you are working with children or pregnant women you may need to be off work longer. If your work involves the use of photographic film again you may need more time off.
You will be advised of the actual time you need to take off work. This will either be during your hospital clinic visit or when you are in the Nuclear Medicine Department.
Here is a rough guide to the time off work you may need:
No, but you will be told to follow some simple rules to reduce the risks to them. The length of time you will have to follow these rules depends on the amount of radioiodine your hospital doctor has prescribed. The exact length of time will be discussed with you before you receive your radioiodine.
You will be advised to:
These precautions usually apply for between 11 and 16 days. Again you will be advised about this.
You will also be asked to avoid prolonged close contact with children and pregnant women for between 21 and 27 days.
Yes, you will see either the doctor who saw you in hospital or your GP. You will need a blood test to check the effect of the treatment on your thyroid.
Usually, one treatment is enough. Sometimes however two or three treatments are needed. The blood tests will help decide exactly how many you need.
No, except that your thyroid gland may become under-active. This could happen within a few weeks or many years after treatment. The blood tests which check your thyroid will pick this up.
You will be given tablets called 'Thyroxine' which usually have no side effects.
If you have any other questions, please ask when you come to the hospital. We want you to understand what the treatment involves.
For further information, please contact the Nuclear Medicine Department on:
029 2031 6237 or 029 2031 6236
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.