After initial treatment for thyroid cancer, it is essential that you periodically follow-up with your doctor. Your doctor may recommend you receive a physical examination and full evaluation every 6 months or yearly. The frequency of your follow-up visits may depend on the type of thyroid cancer originally treated, its size and tumor classification.
According to the American Thyroid Association (ATA), the outcome for patients may be excellent, especially for patients:
The ATA indicates that "patients over 45 years of age or those with larger or more aggressive tumors" have a very good prognosis (outcome) but a higher risk for cancer to return. In addition, the ATA states, "The prognosis is not quite as good in patients whose cancer cannot be completely removed with surgery or destroyed with radioactive iodine treatment."1 Even if the prognosis is not very good, many patients live a long time and are monitored more frequently by their doctor.
Follow-up care, also called monitoring usually involves staying current with changes in your medical history (eg, medications, new non-thyroid related diagnoses), physical examination of the neck and ultrasound.
If your surgery required a thyroidectomy, you take a thyroid hormone replacement medication (eg, levothyroxine) daily. Blood tests allow your doctor to monitor the effectiveness of your medication by checking your TSH level (thyroid-stimulating hormone). S/he may adjust your medication from time to time so you don't become hypothyroid and experience signs or symptoms of hypothyroidism.
If you were treated for papillary or follicular thyroid cancer
Your annual blood work may include a test to measure thyroglobulin (Tg)—a protein thyroid cells produce. If you underwent thyroidectomy and radioactive iodine therapy (RAI) (radioiodine remnant ablation), your body should not be able to produce thyroglobulin. If the protein is found in the blood test, it could mean thyroid cancer has returned. Some patients have thyroglobulin antibodies (anti-Tg), so other testing may be necessary.
If you were treated for medullary thyroid cancer
The blood test will check your level of calcitonin; an amino acid. Medullary thyroid cancer originates from the parafollicular cells—or C cells in the thyroid that produce calcitonin. Monitoring for potential recurrence of medullary thyroid cancer may include a neck ultrasound and imaging (eg, CT scan, MRI).
Whole-Body Scan with RAI
Depending on many factors, including your risk for papillary or follicular thyroid cancer recurrence, your doctor may order a whole-body scan (WBC) with a radioactive iodine tracer. This test helps to detect thyroid cells that could indicate recurrence of thyroid cancer. Before the WBC, you and your doctor have the choice of either withholding (stopping) your thyroid medication (eg, levothyroxine) or administering Thyrogen® injections. It is necessary to follow the low-iodine diet for about 2 weeks before the scan. This is necessary to help deplete your body of thyroid hormone enabling any thyroid cells to take up radioactive iodine.
Other Imaging Tests
If you were treated for anaplastic thyroid cancer, your doctor will order one or more of the following imaging tests of your neck and chest.
• CT Scan (computed tomography) with or without contrast dye
• MRI (magnetic resonance imaging) with or without contrast dye
• PET Scan (positron emission tomography)
Bridget Brady, MD, FACS is the first fellowship-trained endocrine surgeon in Austin, Texas. She has a passion for and expertise in disease of the thyroid, parathyroid, and adrenal glands. Dr. Brady has performed thousands of thyroidectomies and parathryoidectomies with a focus on minimally invasive techniques to optimize patients' medical and cosmetic outcomes.
1. American Thyroid Association. Thyroid Cancer FAQs. http://www.thyroid.org/thyroid-cancer/. Accessed July 5, 2016.