Graves' Ophthalmopathy Following External Neck Irradiation for Nonthyroidal Neoplastic Disease

Abstract

Seven patients have been observed who developed Graves' ophthalmopathy 18 to 84 months following X-irradiation to the neck for nonthyroidal neoplastic disease. In none was there evidence of thyroid disease prior to neck irradiation. The primary neoplasms included Hodgkin's disease and carcinomas of the nasopharynx, breast and larynx. Most patients received unilateral or asymmetrical thyroid gland irradiation in doses under 5000 rads. Thyroid scanning or scintigraphy demonstrated residual functioning thyroid tissue in all the patients. The diagnosis of Graves' disease was established by clinical and laboratory parameters, including serum long-acting thyroid stimulator and serum antithyroid antibodies. Four patients developed hyperthyroidism and ophthalmopathy concurrently, while 3 developed ophthalmopathy alone. HL-A typing for histocompatibility antigens revealed that none of 5 Caucasian patients tested was type HL-A8, an antigen present in about 50% of Caucasian patients who apparently develop Graves' disease spontaneously. These results suggest that thyroidal injury may be an important factor in the etiology of radiationassociated Graves' disease and that the patients herein reported may be genetically different from the latter group.