Thyroid Remnant Radioiodine Ablation with Recombinant Human Thyrotropin

Initial treatment for most patients with differentiated thyroid cancer seeks to eliminate the entire primary tumor, to obtain sufficient material to properly stage the tumor, and to prepare the patient for a comprehensive surveillance program [1]. This often includes a total thyroidectomy and radioactive iodine (RAI) remnant ablation (RRA). The goal of RRA is to eliminate not only normal thyroid cells but also to destroy any residual microscopic thyroid carcinoma that may remain following total thyroidectomy and appropriate lymph node dissection. RAI uptake into thyroid cells is enhanced by a preparatory low-iodine diet and elevated levels of thyrotropin (TSH). For the past 40–50 years, endogenous TSH production was stimulated by several weeks of a hypothyroid state induced by thyroid hormone withdrawal (THW) prior to RAI. However, moderate to severe hypothyroid symptoms significantly reduce the quality of life for many patients and delay the clearance of radioiodine from the whole body.