Detecting hypothyroidism after treatment for laryngeal or hypopharyngeal carcinomas: a nationwide survey in The Netherlands.

A survey to evaluate the management of thyroid function testing was performed in the major institutions treating head and neck cancer in The Netherlands. In July 2006, a questionnaire considering laboratory tests, selection of patients, scheme and treatment of hypothyroidism was sent to physicians who treat head and neck cancer patients in 19 hospitals in the Netherlands including all eight head and neck centers of the Dutch Head and Neck Oncology Cooperative Group (Nederlandse Werkgroep Hoofd-Halstumoren; NWHHT). Thirty-two of thirty-nine (84%) questionnaires were returned. Twenty-four (75%) physicians tested only when symptoms were mentioned, 42% tested all patients treated with different treatment modalities (radiotherapy, chemotherapy or surgery). Most physicians screened annually (32%) or every 6 months (24%) on hypothyroidism. All physicians screened for TSH, 18 physicians (69%) tested free T4 as well. Fifty-eight percent of physicians referred their patients to another department for supplementation therapy when thyroid function is tested abnormal. Twenty physicians (65%) would appreciate guidelines on screening although 75% are aware of the guidelines of the Dutch Head and Neck Oncology Cooperative Group. There is a need for more clear and detailed guidelines in which recommendations on patients' selection, intervals and laboratory measurements of screening for hypothyroidism and its treatment are provided.