Background: To determine time of onset and risk of hypothyroidism after total laryngectomy (TL) with and without (hemi)thyroidectomy in relation to treatment regimen, that is, preoperative radiotherapy (RT-TL), postoperative radiotherapy (TL-RT), and postoperative re-irradiation (RT-TL-RT).
Methods: Retrospective review of 128 patients treated by RT-TL (51 patients), TL-RT (55 patients), and RT-TL-RT (22 patients). Risk of hypothyroidism was determined by multivariable Cox regression analysis and euthyroid survival was calculated using Kaplan-Meier method.
Results: Hypothyroidism developed in 69 (54%) patients. The median onset of hypothyroidism was later (P < .01) and the risk of hypothyroidism was lower (hazard ratio 0.49; P = .014) in the TL-RT group compared to both other treatment regimens. Euthyroid survival did not differ between the treatment regimens. Two years euthyroid survival was 24% with and 61% without (hemi)thyroidectomy (P < .001).
Conclusions: Patients treated with TL-RT have later onset of hypothyroidism. Higher risk for hypothyroidism is associated with salvage TL after radiotherapy and (hemi)thyroidectomy.
Keywords: hemithyroidectomy; hypothyroidism; radiotherapy; total laryngectomy.
© 2019 The Authors. Head & Neck published by Wiley Periodicals, Inc.