Stereotactic radiosurgery for hypersecreting pituitary tumors: part of a multimodality approach

Surgical and medical therapies successfully achieve biochemical remission in the majority of patients with secretory pituitary adenomas. Nevertheless, continued hypersecretion after first-line therapy occurs and requires adjunctive therapy to prevent morbidity and premature mortality. For patients in whom medical and surgical therapy have failed, gamma knife surgery (GKS) is performed with the goal of controlling tumor growth and excess growth hormone (GH) production. The authors report their experience with GKS in patients in whom surgical and medical therapies failed.

The neuroendocrine service at the University of Virginia has treated 220 patients with secretory adenomas. The authors evaluated the biochemical results in patients with acromegaly followed for greater than 18 months (64 patients) as well as those with Cushing disease (45 patients), Nelson syndrome (14 patients with adequate follow up [27 overall]), and prolactinomas (19 patients) followed for at least 12 months posttreatment. Biochemical remission occurred in 36% of patients with GH-secreting adenomas, 73% of those with Cushing disease, 14% of those with Nelson syndrome, and 11% of those harboring prolactinomas. Recurrence after biochemical remission was documented in four patients with Cushing disease. New hormonal deficits have occurred in 28% of patients with acromegaly, 31% with Cushing disease, 36% with Nelson syndrome, and 21% with prolactinomas. Minor visual deterioration developed in one patient with Cushing disease.

Gamma knife surgery offers an important treatment modality in patients with secretory adenomas refractory to surgical and medical interventions.