Follow-up of differentiated thyroid cancer.

The aim of post-surgical follow-up for differentiated thyroid carcinoma is the early identification of the small proportion of patients who have residual disease or develop a recurrence. When total thyroidectomy and radioiodine ablation have been the initial treatment, three powerful tools are available for the follow-up: basal and TSH-stimulated serum thyroglobulin (Tg) measurement, iodine-131 whole body scan (WBS) and neck ultrasound. Serum Tg measurement is the most sensitive and specific marker of differentiated thyroid cancer. Undetectable serum Tg levels are found in the large majority of disease-free patients, while elevated concentrations of serum Tg are associated with the presence of residual or metastatic thyroid tissue. In the last case, WBS under TSH stimulation (either after withdrawal of L-thyroxine therapy or after recombinant human TSH stimulation) and neck ultrasound are the most informative tests for the detection of distant or local metastases, respectively, that require more appropriate treatment (surgery and/or radioiodine therapy). Using this strategy, most patients will achieve definitive cure and will have a normal quality of life.