Thymus irradiation for myasthenia gravis.

Twenty-eight patients with progressive myasthenia gravis without thymoma received treatment of 3000 rads (30 Gy) to the anterior mediastinum, and a followup was conducted for five to 18 years. Twenty-four patients had generalized myasthenia, and four had ocular myasthenia gravis. Twenty patients with generalized myasthenia survived the several month post-treatment period and improved, but four died during that period. The improvement lasted a median of 1.5 years, and older patients had longer remissions than younger patients. The four patients who had ocular myasthenia did not change after treatment. Mediastinal irradiation produces a temporary remission in generalized myasthenia.