*4.3. Treatment*

All patients underwent total thyroidectomy with or without lymphadenectomy. Surgery was followed by (adjuvant) initial radioactive iodine therapy [29]. Prior to RAI therapy, patients were stimulated with recombinant human TSH (rhTSH, Thyrogen®, Sanofi Genzyme, Cambridge, MA, United States) i. m. on two consecutive days or underwent hormone withdrawal prior to RAI therapy to achieve TSH levels ≥ 30μU/mL according to current guideline recommendations [11]. The administered radioiodine activity depended on the tumor stage as well as on the time of inclusion and ranged from 2.0 to 7.4 GBq I-131 (54–200 mCi).
