Primary hypothyroidism as a complication after treatment of tumours of the head and neck

Abstract

In 100 successive patients treated for tumour in the head and neck region, the function of the thyroid gland was evaluated during follow-up by determination of the serum levels of thyroid stimulating hormone and thyroxine. Radiation therapy alone did not lead to hypothyroidism, 4 patients had no dysfunction after laryngectomy for recurrent tumour after irradiation. Ten of 17 (59%) patients treated with irradiation and surgery including hemithyroidectomy and with a follow-up period of more than one year developed functional disturbance; in the absence of hemithyroidectomy one of 10. In patients who underwent hemithyroidectomy and developed hypothyroidism, the interval between surgery and postoperative irradiation was shorter than in those who did not develop functional disturbance (31 versus 49 days).