Remnant Ablation

After thyroid surgery, some patients may require a second step in the initial treatment of thyroid cancer. This step is called thyroid remnant ablation. The thyroid remnant is any remaining thyroid tissue that the surgeon was not able to remove during the thyroidectomy. Thyroid remnant ablation is not recommended for all patients; this will depend upon risk factors such as tumor size.

Thyroid remnant ablation is performed by giving you a dose of radiation in the form of a capsule or liquid. This is called radioactive iodine which targets and destroys any remaining thyroid tissue or cells that may be present in the body. These cells may be normal thyroid cells, cancerous thyroid cells, or both. This procedure is usually done several weeks after the thyroidectomy.

For the radioactive iodine to be taken into the thyroid cells effectively, the patient needs to have an elevated thyroid stimulating hormone (TSH) level. This elevation can be accomplished by taking the patient off their thyroid hormone therapy; however, the patient will then experience the symptoms and effects of hypothyroidism. In December 2007, another option for increasing the TSH levels for purposes of ablation was approved by the FDA. Thyrogen (rhTSH) was approved for use as an adjunct treatment for radioiodine ablation of thyroid tissue remnants in patients who have undergone a near-total or total thyroidectomy for well-differentiated thyroid cancer. Using Thyrogen allows a patient to continue on their thyroid hormone therapy, avoiding the symptoms and effects of hypothyroidism when undergoing remnant ablation. Thyrogen is delivered in 2 injections prior to the thyroid remnant ablation procedure. Both methods of increasing TSH, withholding thyroid hormone therapy or using Thyrogen, have shown comparable success rates in thyroid remnant ablation.[1]

There is currently one option that allows you to stay on your thyroid hormone therapy in preparation for thyroid remnant ablation:

Thyrogen®, (thyrotropin alfa for injection), a version of TSH manufactured by biotechnology that is similar to the TSH that your body naturally produces. Using Thyrogen allows a patient to continue on their thyroid hormone therapy in preparation for thyroid remnant ablation. Thyrogen must be prescribed by your doctor. Go to About Thyrogen for more information


  1. American Thyroid Association Guidelines Taskforce. Management guidelines for patients with thyroid nodules and differentiated thyroid cancer. Thyroid 16 (2): 109-141, 2006. See the ATA Guidelines.



Download these resources to learn more about thyroid cancer and Thyrogen, including how to manage your Thyrogen treatment.


Thyrogen® (thyrotropin alfa for injection) is indicated for use as an additional tool to identify thyroid disease (by testing the blood for a hormone called thyroglobulin), with or without a radiology test using a form of iodine, in the follow up of patients with a certain type of thyroid cancer (known as well differentiated thyroid cancer).

Thyrogen® (thyrotropin alfa for injection) is also indicated for use as a preparation for treatment with a form of iodine to remove left over thyroid tissue in patients who have had surgery to take out the entire thyroid gland for a certain type of thyroid cancer (known as well differentiated thyroid cancer) and who do not have signs of thyroid cancer which has spread to other parts of the body.

Important Safety Information

  • Since Thyrogen was first approved for use, there have been rare reports of events that led to death in patients with several serious health problems; rare reports of central nervous system problems such as stroke and weakness on one side of the body; and rare reports of a quick and painful growth of cancer tumors that have returned to different sites in the body.
  • Before getting Thyrogen, your doctor should talk to you about finding medical help immediately if you have any central nervous system problems after you get Thyrogen. Your doctor may need to treat you with a glucocorticoid (a medication to help prevent an increase in the size of the cancer tumor) if you may have cancer tumors near your windpipe, in your central nervous system, or in your lungs.
  • When Thyrogen is used to help detect thyroid cancer, there is still a chance all—or parts of—your cancer could be missed.
  • In a study of people being prepared for treatment with a form of iodine after thyroid surgery, results were similar between those who received Thyrogen and those who stopped taking their thyroid hormone. Researchers do not know if results would be similar over a longer period of time.
  • Your doctor may take extra steps to care for you during Thyrogen treatment if you have heart disease and large amounts of remaining thyroid tissue after surgery.
  • If you are over 65 years old and did not have your entire thyroid removed during treatment of your cancer, you may be at risk for abnormal heartbeat while receiving Thyrogen. Because of this, you and your doctor will need to carefully consider the risks and benefits of Thyrogen before starting it.
  • In clinical studies, the most common side effects reported were upset stomach, headache, tiredness, throwing up, dizziness, prickling and tingling sensation, weakness, difficulty sleeping, and diarrhea.

Please see full Prescribing Information.