Radiation therapy in the treatment of pituitary adenomas

Seventy-eight patients with pituitary adenomas were seen in the Department of Radiation Oncology at Hahnemann University between 1961 and 1986. Most were treated with megavoltage photons with or without prior surgery. In this group, 68 patients were followed: 39 were treated with radiation therapy (RT) alone, and 29 were treated with a combination of surgery and RT (S/RT). Patients were followed for 2 to 20 years. Of 68 patients, (97%) experienced complete response to treatment; 86% of the RT patients remained free of disease at 5 and 10 years. In the S/RT group, 100% and 94% remained free of disease at 5 and 10 years, respectively. Total disease-free survivals at 5 and 10 years were, respectively, 91% and 89%. The majority of the failures occurring in the RT group were with growth hormone-secreting tumors and Cushing's disease. Of the 7 patients that failed or recurred (time to recurrence: 1-16 years posttreatment), 6 have been followed: 4 were treated with surgery, 1 with RT, and 1 with S/RT. All 6 have remained free of disease since salvage, with 2- to 14-year follow-up periods. Serious morbidity and mortality have been reported previously with bitemporal field radiation using kilovoltage and low megavoltage RT. However, there was no temporal lobe necrosis or death in any of the patients in this study.