The quality of the Tg and TgAb methods selected by the laboratory will impact the clinical management of DTC patients. Since no current Tg or TgAb method is per­fect, it is important for physicians managing patients with DTC to understand the technical limitations of these tests and carefully select the laboratory to per­form the tests. The use of quality Tg and TgAb assays improves the overall cost-effectiveness of management of DTC patients by minimizing costly imaging proce­dures. Even when high quality serum Tg and TgAb test results are available, the values have to be interpreted relative to the characteristics of the assays used and the patient-specific physiological factors that control Tg secretion.