How does the Iodine 131 treatment cure hyperthyroidism in my cat?
Iodine 131 emits beta particles that kill cells instantly. The beta particles can only penetrate distances of one to two millimeters. The only organ in the body that uses iodine is the thyroid gland. The tumor cells are destroyed as they trap radioactive iodine. Normal thyroid tissue has become dormant due to suppression by the pituitary gland. Since the normal thyroid tissue is dormant, only the tumor cells take up the iodine 131. Destruction of the tumor cells allows the normal thyroid tissue to return to normal function over several months. Back to top ^ What are the expected results of the treatment? More than 95% of cats given a single dose of iodine 131 will return to normal thyroid function within three months of treatment. Some cases can take longer to return to normal thyroid function. A small percentage of cats treated with iodine 131 will not be cured with one dose. These cats may have a thyroid carcinoma. Carcinomas often do not respond to one dose of iodine 131. Cats with
