Final answer:
Radioiodine (I-131) Therapy is used as an alternative treatment for large thyroids or when thyroid cancer is a concern. It works by leveraging the iodine-absorbing properties of the thyroid gland to target and destroy abnormal thyroid tissue or cancer cells with radioactive iodine.
Step-by-step explanation:
When thyroids are very large or when cancer is a concern, a common treatment option is Radioiodine (I-131) Therapy. This type of therapy involves using a radioactive isotope of iodine. Because the thyroid gland uses iodine to produce hormones and tends to absorb iodine from the bloodstream, radioactive iodine can be used effectively to treat an overactive thyroid or thyroid cancer. The thyroid cells, particularly cancerous cells, concentrate the iodine, which allows the radioactive material to destroy excess thyroid tissue or thyroid cancer cells. This treatment is also used for imaging the thyroid gland for diagnostic purposes.
Radiopharmaceuticals, such as radioactive iodine, can achieve a favorable therapeutic ratio by being localized in target tissues, such as cancerous cells in the thyroid. These compounds can also be attached to antibodies to target specific cancerous tissues, an approach that aids in localizing the radiation to abnormal tissue.