Follow up

Once your treatment is completed, you will have regular check-ups and tests. These will probably continue for several years. If you have any problems, or notice any new symptoms between appointments, let your doctor know as soon as possible.

Thyroglobulin

Thyroglobulin is a protein that is normally made only by the healthy thyroid gland but can also be produced by papillary or follicular thyroid cancer cells. Levels of thyroglobulin can be detected in the blood.

When the thyroid gland has been removed and radioactive iodine given to destroy any remaining cancer cells, there should be no thyroglobulin being produced, unless there are still residual cancer cells. This makes the thyroglobulin blood test a useful way of detecting any remaining papillary or follicular cancer cells. The blood test is often repeated every 6-12 months.

You may also have radioactive iodine scans (the same as the thyroid radioisotope scan) from time to time, to check whether any thyroid cancer cells remain in your body.

Before a thyroglobulin blood test or a radioactive iodine scan you will need to stop taking your thyroid hormone replacement tablets. If you are taking thyroxine (T4) you will need to stop taking it 4-6 weeks before the scan. If you are taking triiodothyronine (T3) the tablets will need to be stopped 2-3 weeks before. This is done so that the body will produce enough thyroid-stimulating hormone (TSH) to make the tests as accurate as possible. TSH makes any thyroid cells, or thyroid cancer cells, that may be left in your body produce thyroglobulin and absorb radioactive iodine.

Stopping the hormone replacement tablets will mean that your levels of thyroid hormones will get lower. As a result you will begin to develop the symptoms of hypothyroidism, such as depression, weight gain, forgetfulness, decreased concentration and tiredness (see page 8). This may affect your ability to drive or operate machinery. Once the tests are completed you can start taking your tablets again. The symptoms should begin to reduce as the level of thyroid hormones increases in your bloodstream.

To overcome the problems of withdrawing from your hormone replacement treatment, it may be possible to be treated with recombinant human TSH (or rhTSH). This new, synthetic drug is similar to the TSH produced in your body. If you are given rhTSH you do not need to stop taking your thyroid hormone replacement tablets, and will not develop the symptoms of hypothyroidism.

The drug rhTSH is given as an injection, usually into the muscle in your buttocks. You will usually be given two injections, 24 hours apart. On the next day, if you are having a scan, you can be given the radioactive iodine, and the scan will be done 48-72 hours later. The thyroglobulin blood test is done 72 hours after your second injection of rhTSH.

There are very few side effects to rhTSH. Some people have nausea (feeling sick), vomiting (being sick), headaches and weakness. Also, rhTSH is not suitable for everyone, and your doctor can tell you if you are able to have this treatment.

For people whose treatment is over apart from regular check-ups CancerBACUP’s section What now? gives useful advice on how to keep healthy and adjust to life after cancer.