Alterations in serum thyrotropin (TSH) and thyroid function following radiotherapy in patients with malignant lymphoma.

ABSTRACT Seventy-seven of 174 patients (44%) with lymphomas who had lymphangiography and who received high-dose bilateral neck irradiation developed elevated serum TSH concentrations. Many of the elevations were recorded during the first post-treatment year. Elevated serum TSH values were observed with a higher frequency in treated patients under 20 yr of age. In untreated (X-irradiation) Hodgkin's disease, serum TSH levels were normal. Similarly, normal values were seen in patients whose field of irradiation did not include the neck. Nineteen patients developed radiation-induced pericarditis; 16 of the 19 had elevated serum TSH levels and 9 were clinically hypothyroid. Twenty-five patients (11%) developed clinical hypothyroidism and/or showed evidence of thyroid hypofunction by laboratory test other than serum TSH. The post-treatment incidence of abnormally high serum TSH levels was lower in a group of patients with tumors involving the neck region who received irradiation without prior lymphangiography,...