Radioiodine imaging and treatment in thyroid disorders.

The thyroid produces thyroid hormones that regulate metabolism and are essential to proper development and differentiation of the cells in the body. Iodine is an essential element in thyroid hormone synthesis. The thyroid has the ability to concentrate and incorporate iodine into thyroid hormone. Incorporation of iodine is essential to the formation of thyroid hormone. Thyroid disorders may be imaged and treated with radioiodine. Iodine uptake by thyroid follicular cells lends itself to imaging of functional characteristics of the gland. Gamma camera and, increasingly, PET imaging of thyroid disorders permit delineation of thyroid functional status. Iodine uptake also permits treatment, using I-131, of hyperthyroid disease and cancer, for which I-131 is the primary treatment.