Treatment of acromegaly with megavoltage radiation therapy

From 1956 to 1972, 22 previously untreated patients with acromegaly received high dose (average equivalent dose 5700 rad in 5.66 weeks) megavohage (4-4.8 MeV) irradiation at Stanford, 3 post-operatively and 19 as the only intended treatment. Two patients required surgical intervention for deteriorating vision 3 months after initial treatment by irradiation alone, but received no additional treatment. Four patients (18.2%) have died 5-11 years after treatment, 2 of suicide and 2 of cerebrovascular accidents. Eight patients (36%) experienced improvement of their soft tissue acromegalic features whereas the remainder, including the 4 who died, had shown no progression of disease with follow-up ranging from 20 months to almost 18 years. Radiation-induced hormone deficiencies were limited to a need for thyroid in one of 11 patients initially euthyroid and a subsequent need for testosterone in 2 of 6 men approximately 4 years after treatment. Considerations in the treatment of patients with acromegaly and plans for a limited controlled study at Stanford are presented.