Thyroglobulin
• A very sensitive marker of recurrence of thyroid cancer.
• Secreted by the thyroid tissue.
• After total thyroidectomy and RAI ablation, the levels of Tg should be
<0.27 micrograms/L.
• Measurement of Tg levels could be made difficult in the presence of
TgAb, which should be checked.
• Coming off thyroid hormones or giving recombinant TSH increases the
sensitivity of Tg to detect recurrence, but this may not affect survival rates.