Voice Outcome of Total Thyroidectomy in Comparison With Administration of Recombinant Human TSH

Background and Objectives: The larynx is an end-organ target for hormones, and thyroid hormone may act on the larynx. We objectively compared and analyzed the phonetic characteristics of patients who underwent total thyroidectomy before and after radioiodine therapy (RIT) according to administration of recombinant human TSH (rh-TSH). Subjects and Methods: Ninety-one patients who had undergone a total thyroidectomy participated (50 patients without rh-TSH, 41 patients with rh-TSH). Voice samples were obtained postoperatively (Post-OP), before high-dose RIT (Pre-RIT), and after high-dose RIT (Post-RIT). Frequency-, perturbation-, and noise-related parameters were evaluated for acoustic analysis, and the voice handicap index (VHI) was used for the subjective evaluation. Results: Frequency-related parameters decreased significantly in patients without rh-TSH administration, but not changed at three periods in patients with rh-TSH administration. Pitch perturbation parameters were not changed at each period in two groups, but amplitude perturbation parameters were changed significantly in two groups. The functional scores of the VHI increased significantly at Pre-RIT in two groups and physical scores increased in patients without rh-TSH at Pre-RIT. Conclusion: The hypothyroidism after total thyroidectomy affects phonation significantly. Our results suggest that rh-TSH administration during RIT resulted in improving voice results during RIT in the patients with total thyroidectomy.