Radiation therapy of pituitary tumors: results in 95 cases

Between 1967 and 1985 95 patients with pituitary adenoma received radiation therapy at the University of California, Los Angeles (UCLA), and the West Los Angeles Veterans' Administration (VA) Medical Center. Seventy of these patients received radiation therapy immediately as adjuvant therapy following incomplete resection, and 25 were irradiated as primary treatment or after surgical failure. The majority of cases (87%) presented clinically with macroadenomas. Two-thirds of the patients were treated with parallel opposed lateral portals to a midline total dose of 50 Gy. The mean follow-up was 7 years (range: 30-250 months). In our series, there is a difference in response by disease subtype. The control rates were 83% (30 of 36) for nonfunctioning adenoma, 60% (nine of 15) for growth-hormone secreting adenoma, 44% (16 of 36) for prolactin secreting adenoma, three of five for Nelson's syndrome, and three of three for Cushing's disease. There was a tendency for a better response rate with a total dose of greater than or equal to 50 Gy for prolactinoma. None of the patients were known to develop brain necrosis or radiation-induced sarcoma. An analysis of these results and a review of the literature is presented here.