However, even though thyroid cancer has a very good prognosis and most patients stay healthy after overcoming the disease, a recurrence (so-called relapse) cannot be ruled out.
Follow-up examinations are scheduled at regular intervals and the time period between these follow-ups will become longer over time, especially when there are no symptoms of recurrence and your doctor considers your risk of recurrence to be low. Your doctor will take into account the stage of your cancer at the time of diagnosis, the nature of your initial treatment and any follow up test results to assess your risk of recurrence over time.
You will be seen by your doctor after surgery to evaluate your initial treatment. This is to make sure that your cancer has been successfully treated and to check the dose of your hormone replacement. This can involve a number of tests and investigations, including;
- Palpation of the neck
- Ultrasound of your neck
- Blood tests
- If your blood tests show high hormone levels, your doctor may request X-rays, CT or MRI scans
Calcitonin is a hormone produced by the C cells in the thyroid, and it is particularly important for regulating bone health. During surgery, the whole thyroid, including calcitonin-producing C cells, is removed. As a result, after surgery, calcitonin should be undetectable in the blood. As medullary thyroid cancer causes levels of calcitonin to rise, monitoring blood levels after surgery can be a useful way to tell if your cancer has come back or has got worse. Testing for calcitonin involves having a blood sample taken and tested in the lab.
Carcinoembryonic antigen (CEA) is a set of proteins which are involved in cell adhesion, and which are secreted by the C cells. In a number of cancers, including medullary thyroid cancer, the level of CEA can increase and it is therefore used as a routine marker along with calcitonin levels, to monitor the disease. It involves having a blood sample taken and tested in the lab.
Calcium levels are monitored following thyroidectomy to evaluate the health of your bones. If you experience any symptoms or you have persistently prolonged hypocalcaemia (low calcium levels), treatment with oral calcium and calcitriol is indicated.
This is a sensitive way to find any recurrent of thyroid cancer in the neck. It involves moving an instrument along your neck; it is not painful and does not involve and radiation exposure.
Whole body scan (scintigraphy)
Whole-body scanning is a diagnostic imaging technique which uses a special camera to create a physical picture of possible cancer cells in your body after you have swallowed a low dose of RAI. This can be done as part of your follow-up and is very similar to ablation itself. Except it involves much lower activities of radioactive iodine, and, thus, there’s no need to stay in the isolation ward.
Similar to when you had your ablation, the higher the TSH levels in the blood, the better any remaining cells will take up iodine. Therefore, you will need to either stop taking your thyroid hormone tablets for two to six weeks beforehand, or receive two injections of rhTSH.
Two days after ingestion of the low activity RAI, the whole-body scan is performed. Any visible areas of concentrated radiation show that you still have active thyroid cells. If this happens, your doctor will then perform further tests or wants to provide additional treatment with radioactive iodine.
Whole body scan is usually combined with stimulated Tg blood test.
If your doctor suspects your cancer may have spread, a CT/MRI scan or chest X-ray may be performed.
Your thyroid hormone tablets are an important part of living with thyroid cancer and you will need regular blood tests to check your dose is right. The dose of thyroid hormone you need is different for every patient, and it can change as you get older. You should talk with your doctor about what signs to look for that may mean it is time to adjust your dose.
Calcium and vitamin D
You may need extra calcium or vitamin D to maintain bone health. These are taken in tablet form every day. Your doctor will monitor how long you need to take these for.