Myxoedema After Deep X-ray Therapy to the Neck

Abstract

Five women suffering from malignant disease not arising from the thyroid gland developed myxoedema after therapeutic irradiation of the neck. The intervals between completion of radiotherapy and the diagnosis of myxoedema were 3 months, 5 months, 12 months (two patients), and 36 months respectively, and in all cases the thyroid gland was directly irradiated. The development of myxoedema, therefore, is believed to be related to radiotherapy. The dose of radiation was far below that necessary to ablate the normal thyroid, and thyroid auto-antibodies in low titre were detected in all the patients. Myxoedema was unlikely, therefore, to have been a direct effect of radiation, and was probably mediated by an autoimmune reaction. The possibility is discussed that the development of thyroid autoimmunity was related to irradiation of the gland. © 1965, British Medical Journal Publishing Group. All rights reserved.