Differentiated forms of Thyroid Cancer (e.g. Papillary and Follicular) can be treated with radioiodine (radioactive 131Iodine (131I)) which, after entering the bloodstream through ingestion, targets only the thyroid cells in the body. This form of radiation treatment can be referred to as “radioiodine therapy”.
At QAH, differentiated thyroid cancers are initially treated by total or near total thyroidectomy surgery followed up with radioiodine therapy used as an adjuvant treatment. The radioiodine therapy is to improve the outcome of the overall treatment and so decrease the chances of a relapse in thyroid cancer. If relapse does occur, radioiodine therapy will be
used as the primary treatment of the residual/recurrent thyroid tissues and cells.
If you are prescribed radioiodine therapy for the treatment of thyroid cancer, you will be admitted to the designated therapy suite on F5, Oncology ward at QAH. The treatment is given in the form of an iodine capsule which is swallowed. The capsule is smooth and is approximately the size of a Paracetamol. However, if you are unable to swallow capsules, it may be possible to drink the radioiodine in the form of a liquid instead.
When you swallow the capsule, its outer coating dissolves and the radioactive iodine is absorbed into your bloodstream. As the blood circulates around your body, any thyroid cells will 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 the radiation is targeted to only where it is needed.
For several weeks 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 any remaining thyroid cells will pass out of your body through all bodily fluids (predominantly urine). 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 therapy suite while Nuclear Medicine Physics staff monitor the residual levels of radioiodine within your body at regular intervals.
When they are low enough, you will be allowed to go home.
When you leave the hospital, your radiation levels will be a much lower than during your stay. However, there will still be some restrictions that you need to follow including restrictions on the contact and interactions that are had with others. You will be given a written sheet with details of all the restrictions and the Nuclear Medicine Physics staff will advise you in more detail before you leave the ward.
To undergo this treatment, you will be required to go on a low iodine diet for 2 weeks prior to treatment. Also, for 2 hours before and after administration you will not be allowed to consume any food. This is to allow the radioiodine administered to work as effectively as possible.
As you will be radioactive, there will be some restrictions that you have to follow upon leaving the ward. These are dependant on the activity that you are prescribed and will be given to you before the treatment date so that you can
prepare in advance.