Thyroid cancer is a malignant tumor originating from the thyroid gland. According to the American Cancer Society, about 52,890 people in the United States are expected to be diagnosed with thyroid cancer in 2021.

Surgery is usually the first-line treatment for thyroid cancer, but in some cases, radioiodine therapy is used to destroy any remaining cancer cells or to treat metastatic thyroid cancer.

What is radioiodine therapy?

Radioiodine therapy, also known as radioactive iodine ablation, is a treatment used to destroy any remaining thyroid cancer cells or thyroid tissue left after surgery.

The basic principle of the therapy is to use radioactive iodine to kill thyroid cancer cells. Radioactive iodine (I-131) is a type of radioactive iodine molecule that emits radiation, which can destroy thyroid cancer cells.

Preparing for radioactive iodine therapy

Prior to undergoing radioactive iodine therapy, patients may be advised to undergo a low-iodine diet for several weeks, avoiding iodine-rich foods such as seafood, dairy products, and iodized salt.

This is because iodine competes with radioactive iodine for absorption in the thyroid gland. Patients may also stop taking thyroid hormone replacement therapy for a period of time, which can help to increase the uptake of radioactive iodine into the thyroid gland.

Patients will also be advised to hydrate well and increase fluid intake to flush out any residual thyroid hormones, which can decrease the effectiveness of the radioactive iodine therapy.

How is radioiodine therapy administered?

Radioactive iodine therapy is administered in the form of a pill or capsule, which is swallowed by the patient. The capsule contains a specific, calculated amount of I-131 that is customized for each patient based on their individual needs.

Once swallowed, the radioactive iodine is absorbed into the bloodstream and taken up by the remaining thyroid tissue or thyroid cancer cells.

What are the side effects of radioactive iodine therapy?

Radioactive iodine therapy is generally well-tolerated, but some patients may experience side effects such as nausea, vomiting, dry mouth, or a metallic taste in the mouth.

Patients may also experience a transient swelling or tenderness of the salivary glands. It is important for patients to remain hydrated and to follow the instructions given by their healthcare provider to minimize these side effects.

Patients should also avoid close contact with others and avoid becoming pregnant or breastfeeding for a period of time after the therapy.

How effective is radioactive iodine therapy?

Radioactive iodine therapy is a highly effective treatment for thyroid cancer and is considered a standard treatment for most patients with papillary and follicular thyroid cancer.

The effectiveness of the therapy depends on several factors, including the stage of the cancer, the level of thyroid tissue or thyroid cancer cells remaining in the body, and the patient’s overall health. In some cases, multiple doses of radioactive iodine may be needed to achieve the desired effect.

Post-treatment surveillance

After radioactive iodine therapy, patients will require periodic monitoring to assess the effectiveness of the therapy and to detect any recurrence of thyroid cancer.

This may include periodic blood tests to measure thyroid hormone levels, regular physical examinations, and imaging studies such as ultrasound or PET scans.

Conclusion

Radioactive iodine therapy is a safe and effective treatment option for most patients with thyroid cancer.

It is important for patients to be well-informed about the therapy and to follow the instructions of their healthcare provider to maximize its effectiveness and minimize any potential side effects.