Whole Body Scan

Another test that checks for the return or spread of thyroid cancer is called a whole body scan (WBS). To prepare for a WBS, you will be asked to swallow a capsule or liquid that contains a very small amount of radioactive iodine (RAI). This will be absorbed by any remaining thyroid cells in your body. You will then be asked to return for the scan in about 48 hours. This involves lying down under a large camera that scans for x-rays being emitted by any remaining radioactive iodine that may have been captured in your body. If any thyroid or thyroid cancer cells are present, they may show up as spots on the x-ray film. However, if only microscopic thyroid cancer cells are present in the body, they are not always visible on the scan.

How can you improve the sensitivity of a WBS?

In order to improve the sensitivity of a WBS, the test must be able to detect even small amounts of thyroid cells. With thyroid stimulating hormone (TSH) in your bloodstream, any thyroid cells that are present in your body will be stimulated to absorb more radioactive iodine, making it more likely that the WBS will detect them.

There are currently two options to increase TSH levels in your bloodstream:

  • Stop taking thyroid replacement hormones. This approach enhances the accuracy of the test, however, it will induce hypothyroidism, a condition that can potentially have a negative impact on your daily life. Visit the Hypothyroidism section to learn more.


  • Receive Thyrogen®, (thyrotropin alfa for injection), a version of TSH manufactured by biotechnology that is similar to the TSH that your body naturally produces. Thyrogen enhances the accuracy of the WBS test without inducing hypothyroidism because you can continue to take your thyroid hormone therapy. Thyrogen must be prescribed by your doctor. Go to About Thyrogen for more information.

Other tests

In addition to Tg testing and a whole body scan, doctors may recommend an ultrasound of the neck or other, more sophisticated imaging tests such as a positive emission tomography (PET) scan to see if any cancer has returned or spread. Ultrasound is being used more frequently to detect recurrence of cancer in the lymph glands of the neck.


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.