Patients with well differentiated thyroid cancer (DTC) need whole-body scintigraphy (WBS) and thyroglobulin (Tg) measurement in order to detect recurrence. Classically, withdrawal from levothyroxine (L-T4) during 4-6 weeks is needed for TSH elevation (> 30mUI/L), to allow iodine uptake and Tg production. As a result, patients become hypothyroid with impaired quality of life and a potential for tumour flare-up. Recombinant hTSH before WBS prevents hypothyroidism but is not yet approved for radioiodine treatment and is an expensive therapy. L-T3 substitution during the first 2-3 weeks of withdrawal is an alternative used empirically to prepare patients; however, no data exists to prove its benefit upon reducing hypothyroidism.