Endogenous TSH levels at the time of 131I ablation do not influence ablation success, recurrence-free survival or differentiated thyroid cancer-related mortality

Purpose Based on a single older study it is established dogma that TSH levels should be ≥30 mU/l at the time of postoperative 131I ablation in differentiated thyroid cancer (DTC) patients. We sought to determine whether endogenous TSH levels, i.e. after levothyroxine withdrawal, at the time of ablation influence ablation success rates, recurrence-free survival and DTC-related mortality.