Thyroid-stimulating hormone levels after radiotherapy and combined therapy for head and neck cancer

Sixty-eight patients were studied prospectively with serial thyroid-stimulating hormone (TSH) levels after radiotherapy for head and neck neoplasms. Overall, 57% of the patients developed elevated TSH levels. Excluding patients with less than 2 years follow-up, 85% developed an elevated TSH. Ninety-two percent of patients treated with partial thyroidectomy and radiotherapy developed an elevated TSH. Most TSH elevations occurred within 1 year of treatment. The dose of radiotherapy used and the performance of hemithyroidectomy were related to the development of elevated TSH levels (p less than 0.05). The performance of radical neck dissection, gender, hyperfractionated radiotherapy and the use of chemotherapy were not related to the development of an elevated TSH (p greater than 0.05).