Thyroglobulin assays in the postoperative management of differentiated thyroid cancer

Carcinoma of the thyroid gland is the most common endocrine malignancy managed by the head and neck surgeon. Accepted therapy for differentiated macroscopic (greater than 1 to 1.5 cm) lesions is total or near-total thyroidectomy, followed by radioactive iodine treatment. Followup care usually consists of annual total body scan to rule out the presence of metastatic disease. Thyroglobulin, which is elaborated only by thyroid cells, either normal or metastatic, serves as a tumor marker when all functioning tissue has been ablated. The routine use of thyroglobulin assays obviates the expense and inconvenience of an annual scan. This article reviews the usefulness and limitations of serum radioimmune assays in the postoperative management of differentiated thyroid cancer. We also present several representative cases treated at our institution.