XXXX following treatment for head and neck cancer.

@entity1 @entity1375 @entity1955 @entity1374
One hundred ninety-six head and neck @entity1 were studied to determine the effects of radiation therapy and surgery on thyroid function. Serum thyroid-stimulating hormone (TSH) levels were obtained as a screening test for @entity1375 . Elevated TSH levels were found in 57 of the 196 @entity1 (29.1%). The highest incidence of abnormal TSH values (66%) occurred in the group treated with combination radiation therapy and surgery, including partial thyroidectomy. TSH levels rose early in the posttreatment period with 60% of the abnormal values occurring within the first three posttreatment years. Posttreatment @entity1374 was twice as common in @entity1 (48.6%) as in @entity1 (25.4%). When serum @entity1955 levels by radioimmunoassay (T4RIA) were correlated with the elevated serum TSH levels, a similar pattern was seen with 65% of the @entity1 in Group 3 having a decreased T4RIA level indicating @entity1375 . Pretreatment levels of thyroid function including thyroid antibody studies should be established for all @entity1 . Serial TSH levels should be done every three months during the first three posttreatment years and semiannually thereafter as long as the @entity1 will return for follow-up care. All @entity1 treated with combination radiation therapy and surgery who develop elevated TSH levels should be treated with thyroid replacement therapy. @entity1 receiving radiation therapy alone should receive replacement thyroid therapy if they develop a depressed T4RIA value or a pattern of gradually increasing TSH levels.
