Stereotactic radiosurgery for pituitary metastases

Abstract

Background: We evaluated the role of Gamma Knife SRS in the multidisciplinary management of metastatic cancer to the pituitary gland.

Methods: We retrospectively reviewed records of 18 consecutive pituitary metastasis patients who underwent Gamma Knife SRS during a 21-year experience. The median patient age was 57.6 years (range, 27.0-81.1 years). There were 5 patients who had initial surgical resection of their pituitary metastasis, 5 who had fractionated radiation, and 7 who had CT before SRS. The median radiosurgery target volume was 3.5 mL (range, 0.2-18.0 mL), and the median marginal dose was 13.0 Gy (range, 9-18 Gy).

Results: The overall survival after SRS at 3, 6, and 12 months, respectively, was 66%, 36%, and 18%. The median survival after SRS was 5.2 months. The progression-free survival after SRS was 100% and 66.7% at 6 and 12 months, respectively. The only factor associated with an improved overall survival was younger age at presentation. Diabetes insipidus improved in 3 (42.9%) of 7 patients. Neurological symptoms or signs improved in 4 (50.0%) of 8 patients. Three (16.7%) patients developed new neurological deficits due to tumor progression despite SRS.

Conclusion: Development of a pituitary metastasis is an ominous finding in the context of systemic cancer. Stereotactic radiosurgery is an effective palliative approach for most patients with pituitary metastasis.