What is Iodine-131 Therapy?
Iodine-131 therapy uses radiation to damage thyroid tissue, to treat thyroid cancer or a hyperactive thyroid (thyrotoxicosis). The level of this treatment depends on the thyroid problem present. For the treatment of thyroid cancer, the radiation is used to get rid of any excess thyroid tissue after a thyroidectomy. It can also be used to destroy cancer cells that have metastisised from the thyroid gland to other parts of the body, such as the lymph nodes in the neck. If the thyroid is overactive, the radiation reduces the activity of the thyroid to achieve a normal state.
How Does Iodine-131 Therapy Work?
Iodine is required by the thyroid gland in order to produce the thyroid hormones. Iodine-131 is a radioactive form of Iodine, emitting beta radiation that destroys cancer cells. Usually given as a capsule, the Iodine-131 gets taken up by thyroid cells, the only cells in the body that can absorb Iodine. The radiation emitted damages any cancer cells that may be present, or reduces the overall activity of the thyroid to a normal level.
Is this Treatment Safe?
Iodine-131 therapy has been used for over 70 years and is considered to be a safe treatment. Above certain dosage levels, precautions may need to be taken when around children and the general public. As a cancer therapy treatment, an inpatient hospital stay is required to prevent the radiation exposure to others. This treatment is not to be used while pregnant, as the radiation has the potential to adversely affect the unborn child. Side effects after undergoing this treatment are uncommon but may include a tender throat for several days and very occasionally nausea. Further side effects seen in high-dose thyroid cancer treatments include altered taste and an occasional dry mouth. In very rare cases, side effects of multiple high-dose treatments may include the development of secondary cancers in the bone marrow, kidney, bowel and bladder many years after treatment. These side effects are more common in patients that require multiple high-dose treatments, although this is now uncommon in modern thyroid cancer practice.
When Would I Consider Using this Treatment?
This therapy is one of the most common treatments for the thyroid conditions such as thyroid cancer and thyrotoxicosis. Early stage cancer of the thyroid is usually treated with solely surgery (thyroidectomy). Iodine-131 Therapy is considered for patients with large tumours, used after a thyroidectomy to destroy any remaining cancerous thyroid tissue in the thyroid gland area, or to destroy any tumours that may have spread elsewhere in the body.