[Hypothyroidism after combined surgical and radiotherapy treatment of cancer of the ORL area]. / Hypothyroïdie après traitement combiné de chirurgie et radiothérapie pour cancer de la sphère ORL.

INTRODUCTION: Hypothyroidism is a well described complication of head and neck cancer treatment, but routine testing of thyroid function is generally not done. The combination of surgery and radiotherapy seems to increase the risk of thyroid hypofunction. METHODS: Thyroid function was measured in 82 patients treated for head and neck cancer (different types of surgical resection combined with pre- or postoperative radiotherapy). The treatment was undertaken 1 to 220 months before measurement of THS and T4. RESULTS: 43 out of the 82 patients (52%) had abnormal thyroid tests. Hormonal replacement was necessary in 20/43 cases (24%). More than 85% of patients treated by total laryngectomy or pharyngo-laryngectomy, associated with hemithyroidectomy or not, had hypothyroidism and replacement therapy was necessary in more than half of these patients. For the other types of surgery the incidence of hypothyroidism was 32% with 10% of patients needing substitution. DISCUSSION: A high percentage of patients treated by surgery and radiotherapy develop hypothyroidism. In our experience, routine thyroid function testing is necessary in this group.