Postoperative radiosurgery of pituitary adenomas.

From 1984-1990, 52 patients with pituitary adenomas had postoperative radiosurgery for incomplete surgical removal or regrowth of the tumor. The atraumatic Greitz-Bergström fixation head device was adopted for the stereotactic procedure and irradiation was performed with a linear accelerator. Because of the variability of the tumor response, a 10-20 Gy single dose was directed at 1-2 targets and radiosurgery repeated if the result was unsatisfactory. The median radiation dose was 30 Gy. No adverse effects occurred. Regression of pretreatment symptoms caused by tumor mass was observed in 67% of patients. GH and PRL activity decreased in 20 patients, was stable in 11 and increased in 2 prolactinomas. CT studies showed disappearance of the tumor in 4 patients and shrinkage in 36. Postoperative radiosurgery is a valuable method of treatment whenever pituitary surgery has been incomplete.