Radioactive iodine for thyroid carcinoma is given by

Radioactive iodine (131-I) is a radioactive isotope that is administered orally, in a liquid or capsule form.Thyroid tissue concentrates iodine. For this reason, 131I can be given in order to deliver tumoricidal doses of radioactivitydirectly to thyroid tissue, both benign and malignant. In the setting of thyroid cancer, all normal tissue should be removed (total thyroidectomy) along with any gross neck disease (neck dissection) in order for any residual microscopic disease or distant metastases to receive an optimal dose.(Ref: Practical Management of Thyroid Cancer: A Multidisciplinary ApproachErnest L. Mazzaferri et al, page 22)Bailey and Love 27e pg: 819