Radioiodine for Thyroid Cancer and Thyrotoxicosis
Thyrotoxicosis
Radioiodine (I-131) is a form of iodine that is radioactive. It is administered as a small capsule to swallow, although it may be given as a drink. Most of the iodine is absorbed by the thyroid gland and the radioactivity ‘slows down’ the thyroid gland’s production of certain hormones. Any radioiodine that is not absorbed by the thyroid passes out of the body in the urine during the first few days after treatment.
If you are referred for radioiodine treatment you will be given two appointments to attend the Nuclear Medicine department, usually on consecutive Fridays. At your first Friday appointment you will have a scan of your thyroid gland. This involves receiving a small injection into your arm of radioactive liquid which locates in the thyroid. Twenty minutes after the injection you will be positioned in front the gamma camera to take images of your thyroid. You will then be asked to wait for a while until the scan has been processed.
The Nuclear Medicine consultant will see you after the scan to discuss the results and, if appropriate, to prescribe radioiodine treatment. If you are prescribed treatment then you will be asked to stop taking anti-thyroid tablets. Also, the precautions that will be necessary for the first few weeks following the treatment will be discussed with you. NMP team will confirm the date and time when you should come back to receive the radioiodine treatment. This will usually be the following Friday. Please note that you may be in the department for up to 3 hours at your first appointment.
For more information see Related Documents section (File NM4.doc)
or follow this link
Royal College of Physicians: Radioiodine in the Management of Benign Thyroid Disease, 2007.
Thyroid Cancer
Radioactive iodine (131I) is a type of radiation treatment delivered to the body internally to target thyroid cells. In some cases of thyroid cancer, radioiodine is prescribed after thyroid surgery to ablate any thyroid tissue that could not be removed. If you are referred for this treatment you will be admitted to a comfortable and fully equipped designated suite on F5, Oncology ward at QAH. The treatment is given as a single iodine capsule, which is swallowed. However, if you are unable to swallow capsules, it may be possible to drink some liquid instead.
When you swallow the capsule, its outer coating dissolves and you absorb the iodine into your bloodstream. As the blood circulates around your body, any thyroid cells readily absorb the radioactive iodine in the same way as non-radioactive iodine is absorbed from the diet. The uptake of iodine in the body is strictly limited to thyroid cells, which means that the radiation is targeted to where it is needed.
For several days after you swallow the capsule, you will be radioactive. The radioactivity will treat any cancerous thyroid cells remaining in your body. Any radioiodine that is not absorbed by your thyroid will pass out of your body when you use the toilet. The regulations governing radiation state that we need to limit the radiation dose received by people who do not need it. Patients are therefore required to remain in hospital while NMP staff monitors residue level of radioiodine in your body in regular interval and then will allow you to go home, if the remaining level of radioiodine has reduced to a certain level.
When you leave the hospital the radiation level will be a much lower than during your stay. However, there will still be some restrictions that you need to follow. Duration of the restrictions depends on your level of radiation when you leave the hospital. You will be given a written sheet with all the details and the staff from the Nuclear Medicine Physics Department will advise you in more detail before you leave the ward.
For more information see Related Documents section (File NM5.doc)
or follow these links
and
ThyCa: Thyroid Cancer Survivors’ Association, Inc (including low iodine recipes)
