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.



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

Limitations of Use:

The effect of Thyrogen on long term thyroid cancer outcomes has not been determined.

When Thyrogen is used to help detect thyroid cancer, there is still a chance all or parts of the cancer could be missed.

Thyrogen is also used to help patients prepare for treatment with a form of iodine to remove leftover thyroid tissue in patients who have had surgery to take out the entire thyroid gland for patients with well differentiated thyroid cancer who do not have signs of thyroid cancer which has spread to other parts of the body.

Limitations of Use:

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.


There have been reports of events that led to death in patients who not had surgery to have their thyroid gland removed, and in patients with thyroid cancer cells that have spread to other parts of the body.

Patients over 65 years old with large amounts of leftover thyroid tissue after surgery, or with a history of heart disease, should discuss with their physicians the risks and benefits of Thyrogen.

Thyrogen can be administered in the hospital for patients at risk for complications from Thyrogen administration.

Since Thyrogen was first approved for use, there have been reports of central nervous system problems such as stroke in young women who have a higher chance of having a stroke, and weakness on one side of the body.

Patients should remain hydrated prior to treatment with Thyrogen.

Leftover thyroid tissue after surgery and cancer cells that have spread to other parts of the body can quickly grow and become painful after Thyrogen administration.

Patients with cancer cells near their windpipe, in their central nervous system, or in their lungs may need treatment with a glucocorticoid (a medication to help prevent an increase in the size of the cancer cells before using Thyrogen.)


In clinical studies, the most common side effects reported were nausea and headache.


Pregnant patients: Thyrogen should be given to a pregnant woman only if the doctor thinks there is a clear need for it.

Breastfeeding patients: It is not known whether Thyrogen can appear in human milk. Breastfeeding women should discuss the benefits and risks of Thyrogen with their physician.

Children: Safety and effectiveness in young patients (under the age of 18) have not been established.

Elderly: Studies do not show a difference in the safety and effectiveness of Thyrogen between adult patients less than 65 years and those over 65 years of age.

Patients with kidney disease: Thyrogen exits the body much slower in dialysis patients and can lead to longer high TSH levels.

See full Prescribing Information for more details.