A whole-body iodine scan is a nuclear medicine imaging procedure to look for remaining thyroid tissue and detect whether cancerous cells have spread to other parts of the body. The procedure is usually done on a select group of people who have undergone thyroid surgery or radioactive iodine therapy for differentiated thyroid cancer. Your doctor can examine the results of the scan and decide on the best course of treatment. Dr. Nikunj Jain, Co-Founder and Head of Nuclear Medicine, Molecular Diagnostics and Therapy, speaks about the importance of nuclear medicine investigations and scans for thyroid cancer.
What Is a Whole-Body Iodine Scan?
A whole-body iodine scan is a diagnostic imaging test that uses a tracer containing iodine to look for cancerous cells. The normal thyroid cells as well as the cancerous cells (differentiated) have the unique ability to absorb iodine. A gamma camera detects the radiation given off by the tracer and creates an image of the thyroid area and other parts of the body. The whole-body iodine scan test helps identify iodine-avid thyroid tissues or cancer in other parts of the body apart from the thyroid bed. The scan may not always pick up cancerous tissues, as not all cancer cells have the ability to absorb iodine. Uptake of iodine by itself does not confirm cancer.
Why Is a Whole-Body Iodine Scan Done?
The scan is often done after thyroid surgery to determine if there are any remaining thyroid tissues. The procedure can also help determine whether cancer has spread to other parts of the body or recurred in people who have had cancer earlier. Moreover, it can help evaluate if the treatment with radioactive iodine was successful or not. Your doctor may recommend a Whole-Body Iodine Scan if they believe the findings will impact the patient’s further treatment. The decision to undergo this procedure is based on the kind of cancer, treatment, blood tests, and the likelihood of recurrence for each individual.
How Is a Whole-Body Iodine Scan Performed?
The outpatient procedure is relatively simple and does not require any surgery. First, the nuclear medicine team reviews your medical records, previous reports, and current medications. They might give you a capsule or liquid of the tracer according to the directions. Then, you wait for a few hours or come back the next day or later, as advised. This is required to allow the radioactive tracer to reach the thyroid cells or other parts of the body that can absorb iodine. You will be asked to lie down on a special table while the gamma camera scans your body to capture images of the radioactive tracer. It is essential to remain as still as possible during the scan to avoid smudging of the images. In some cases, additional images might be required to take a closer look at a specific part of the body. The Whole-Body Iodine Scan is free of discomfort; however, the number of visits and the time required are determined by the tracer amount introduced and the facility’s instructions.
What Do Whole-Body Iodine Scan Results Mean?
The images of a whole-body iodine scan are assessed by a nuclear medicine specialist. He/she analyzes the results of the scan in conjunction with the patient’s medical history, blood tests, and other imaging tests. If iodine is detected in the thyroid, it indicates the presence of remaining thyroid tissue after surgery. The detection of iodine in other parts of the body may indicate the spread of cancer. However, it is important to analyze other factors such as the pattern of uptake to arrive at a definitive diagnosis. If a whole-body iodine scan is negative, this means that the doctors conducting the test did not detect any abnormal uptake. However, it is possible that abnormal thyroid tissues may not be detected in the scan, as some cancer cells have lower uptake of iodine. In such a scenario, your doctor may recommend additional tests and scans to confirm whether cancer is present or not. Thyroglobulin blood test, ultrasound scan, CT scan, and MRI are some of the many scans and tests that may be recommended. The results of the scans and tests are reported by the nuclear medicine specialist to the treating doctor, who reviews and decides on the next line of treatment.
Are There Any Risks or Side Effects?
A whole-body iodine scan involves exposing the patient to minute amounts of radiation. Exposure to radiation during the scan is not known to cause any side effects. If you have any questions or concerns about the radiation involved in the procedure, you should speak to your treating doctor or nuclear medicine specialist. After the procedure, you may be given certain instructions to prevent exposing others to radiation. The instructions will depend on the type and amount of tracer introduced into the body. It is essential to abide by the instructions given by the nuclear medicine team to prevent exposing others to radiation.
Conclusion
At Molecular Diagnostics and Therapy, nuclear medicine investigations help evaluate and treat patients with differentiated thyroid cancer. Dr. Nikunj Jain, Co-Founder and Head of Nuclear Medicine, has a comprehensive understanding of the role of nuclear medicine in thyroid cancer. If you have been advised to go through a Whole-Body Iodine Scan, it is essential to communicate with your doctor about your earlier treatment and medications. You must also follow the preparation instructions to ensure that the results of the scan can be used to aid your further treatment.