Targeting cancer - Side effects of radiation therapy

Follow-up care

You will have regular check-up after your treatment for thyroid cancer. It is important to keep up with follow-up meetings, to make sure that if the cancer comes back, it is caught and treated as early as possible. If you have any concerns between visits, you should contact your doctor.

At your follow-up visit, your doctor will perform a physical examination (e.g. feel your neck). Depending on the type of thyroid cancer, and the risk of cancer returning, your doctor will recommend scans and blood tests. 
The blood tests monitor the thyroid hormones and tumour markers that can indicate if the cancer has come back (recurred). The scans help to find where any cancer has returned.
You may have the following tests and scans: 
Blood tests
  • Thyroid hormones and TSH are measured as needed, to check you are on the right dose of thyroid hormone replacement and to monitor thyroid stimulating hormone (TSH). The dose of thyroid hormone may be adjusted for your needs, including changes with age.

  • TSH is monitored for TSH suppression or lowering. TSH suppression aims to reduce the risk of cancer coming back, and is used particularly for patients with a higher risk of recurrence.

  • Thyroglobulin. If you have been treated for papillary or follicular cancer, blood tests will be done for thyroglobulin, which is a tumour marker protein made by thyroid cells. Levels are very low if the thyroid gland has been removed and may rise if the cancer comes back. Anti-thyroglobulin antibodies may also be measured.

  • Sometimes the doctor may decide to measure stimulated thyroglobulin, as the test can be more accurate. The doctor would give you instructions about any changes in your medication needed before this test.

  • Calcitonin and a tumour marker protein called carcinoembryonic antigen (CEA) will be measured for patients treated for medullary thyroid cancer. Levels may rise if the cancer comes back.

Neck ultrasound
  • An ultrasound of the neck is used to check the area where the thyroid was removed to see if there is any cancer growing in the thyroid bed. It is also used to check your lymph glands around the neck.

Radioistope scan
  • A radioisotope scan is used to check of there are any cancer cells in your body.  A small amount of radioactive liquid (eg iodine-131) is injected into a vein and after about 20 minutes you will lie under a gamma camera machine.

  • You may need to change your medications before a radioisotope scan to help the cancer cells take up the radioactive iodine and make the test more accurate. Your doctor would give you instructions on any changes needed.

  • The scan measures how much radioactivity has been taken up by the thyroid and also helps to see if the cancer has spread.

  • The scan is painless and has few side effects. You will not be radioactive after the scan.

CT, PET or other scans
  • You may have a CT or PET scan if cancer cells are found elsewhere in your body or if further testing is needed.

  • CT or MRI scans are not used routinely. They may be used when the blood tumour markers suggest the cancer has come back, but it has not shown up on the ultrasound or radioisotope scan. These scans may also assist in planning any further surgery.

Diet and nutrition

It is important for people with thyroid cancer to stay well-nourished and to avoid unplanned weight loss.  If you can’t eat or drink enough, you may become malnourished or begin to lose weight.  In this case, your healthcare team may consider feeding you through a tube for a period.
Maintaining good nutrition is important to help:

  • ensure you get through treatment

  • reduce your risk of infection

  •  recover more quickly

  • keep your strength and energy levels up

What can I do to help my diet and nutrition?

To help your body recover from surgery, you need to be well nourished. You can keep well-nourished and hydrated during and after your treatment by:

  • eating a diet high in protein and calories (energy)

  • eating small meals or snacks, more frequently

  • drinking nourishing fluids, such as milk, milkshakes, smoothies or juice .  Your dietitian may also recommend nutritional supplement drinks which are high in protein and energy.

You may need to make changes to the types of food you eat. If you have a sore throat, you may want to avoid foods that irritate, such as citrus or vinegar, and hard foods, such as chips or toast.  Try to swallow gently and to eat small amounts of healthy, nutritious food.

For patients preparing to have radioactive iodine treatment
For about 2 weeks before treatment, you will need to avoid foods high in iodine such as seafood, iodised salt, some dairy food and any food coloured pink with the additive E127. You need to have a low iodine diet because too much iodine in your body can stop the treatment working so well. Your health care team will provide you with advice on the foods to avoid.

Visit the Cancer Council website for further information about diet and nutrition.