[Clinical evaluation of radiotherapy for endocrine ophthalmopathy]

Ten patients with severe endocrine ophthalmopathy were treated by radiotherapy at Hyogo Medical Center for Adults from May 1984 to February 1988. All but one of the patients had poorly responded to previous systemic or topical corticosteroid therapy. The target of the radiotherapy was both retrobulbar tissues. The radiation field used was about 4 x 4 cm, excluding the pituitary gland and the brain, and was angled 5 degrees posteriorly to avoid the contralateral lens. A total of 2000 cGy was given to each patient over a 2 week-period. Eight of the ten patients showed some response, with 5 of them (50%) having a good to excellent response. Treatment was more effective for soft tissue changes, proptosis and keratopathy, while myopathy was less responsive. As for the duration of the eye signs and symptoms, those of a shorter duration (less then 12 months) responded better. It was also noted that the degree of the eye muscle enlargement on the pre-treatment orbital CT scan was directly correlated to the results of the treatment. Although three of the patients experienced transient headache, there were no serious acute reactions or long term complications. In conclusion, retrobulbar radiotherapy is a well-tolerated, safe and effective treatment for severe endocrine ophthalmopathy.