Thyroid function 10-18 years after mantle field irradiation for Hodgkin's disease

Thyroid function was measured in 81 patients who had been curatively irradiated on a mantle field for Hodgkin's disease 10-18 years ago. 47 patients (58%) had elevated levels of thyroid stimulating hormone, indicating hypofunction of the thyroid gland, compared with 4.6% of controls (hospital visitors) matched for age and sex. The mean free thyroxine index (FTI) was significantly lower in patients than in controls, but all FTI values were still normal. Age at the time of irradiation, sex, time since irradiation and administration of chemotherapy were not significant factors in the development of thyroid dysfunction. A life-long awareness of the possibility of insidiously developing myxedema in these patients is strongly advocated.