Thyroid Cancer Treatment Follow-up - Thyroglobulin (Tg) Test

This test measures the level of thyroglobulin (Tg) protein in the blood. Tg is a protein produced by the follicular cells in the thyroid gland and is used in the synthesis of the hormones T3 and T4. After total thyroidectomy (surgical removal and radioactive iodine treatment) as a cancer treatment, its blood level should drop to an undetectable level. An elevated level thereafter is a sensitive indicator of residual or recurrent thyroid tissue (recurrence), either benign or malignant.