Recurring cancer
An estimated 5-20% of people with a history of thyroid cancer will experience a return of cancerous cells in their neck. An estimated 10-15% of people will experience a return of cancerous cells in other parts of their body, such as their bones. Cancerous cells can return many years after surgery and radioactive iodine treatment has been completed.
Due to this risk, you will be asked to attend regular check-ups, so that if any cancerous cells do return, they can be quickly treated.
Three routine tests can be used to check for the return of cancerous cells. They are:
- thyroglobulin testing
- ultrasound scan of the neck
- a radioactive iodine scan
These are described below.
Thyroglobulin testing
Thyroglobulin is a protein that is released by a healthy thyroid gland, but it can also be released by cancerous cells.
If you have had your thyroid gland removed, there should be no thryoglobulin present in your blood, unless cancerous cells have returned.
Therefore, regularly testing your blood for thryoglobulin can be an effective way of making sure that any cancerous cells have not returned.
For the first few years after surgery, you will probably require thryoglobulin testing every six months. After this time testing will be required once a year.
‘Stimulated thyroglobulin’ is where a person’s thyroglobulin level is tested while they are not on thyroid hormone treatment, in preparation for an iodine scan or shortly after receiving recombinant human thyroid stimulating hormone (rhTSH). The stimulated thyroglobulin test is more sensitive and therefore more valuable than a thyroglobulin test without the above preparation.
Ultrasound scan
An ultrasound scanner uses high frequency sound waves to create an image of part of the inside of the body. Ultrasound scans can be a useful way of detecting any changes or abnormalities inside your neck that could indicate the recurrence of cancer.
Ultrasound scans are increasingly being used in combination with thyroglobulin testing because research has found that it is an effective method of detecting recurring thyroid cancer.
Radioactive iodine scan
After surgery, you may also be asked to attend a radioactive iodine scanning test. This test involves swallowing a small amount of radioactive iodine before your body is scanned using a special camera. The radioactive iodine may highlight any cancerous thyroid cells that may remain in your body.
The preparation for an iodine scan is similar to having radioactive iodine treatment. You will need to go on a low iodine diet and stop taking your thyroid homrome medication. Alternatively, recombinant human thyroid stimulating hormone (rhTSH) can be used without having to interrupt your thyroid hormone medication. As the dose of radioactive iodine that is used for the scan is miniscule (very small), no precautions, such as keeping your distance from others, are required, However, if you think that you may be pregnant, or if you are breastfeeding, you must let the doctors know before your test.
A radioactive iodine scan is usually carried out six to eight months after surgery. If the test results are negative, further testing is not usually required.
