Stereotactic radiosurgery for brain metastases from breast cancer

Background: Stereotactic radiosurgery is an alternative to resection or to radiotherapy alone for patients with brain metastases. Outcomes after radiosurgery for patients with brain metastases specifically from breast cancer have not been defined. Methods: We retrospectively studied survival and tumor control for all patients with brain metastases from boast cancer who underwent gamma knife stereotactic radiosurgery at the University of Pittsburgh. Univariate and multivariate analyses were used to determine which prognostic factors significantly affected survival. Results: Thirty patients underwent radiosurgery between 1990 and 1997. A total of 58 metastases were treated. The median length of survival for all patients was 13 months from radiosurgery and 18 months from diagnosis of brain metastases. The tumor control rate on follow-up imaging was 93%. On multivariate analysis, the only factor that correlated with longer survival was the absence of multiple brain metastases. Age, presence of systemic disease, previous whole brain radiation, location, and total tumor volume did not significantly affect survival. Four patients had tumors with evidence of radiation-induced edema after radiosurgery but did not require resection. Two patients underwent delayed resection for tumor growth after radiosurgery. Conclusions: Stereotactic radiosurgery is an effective treatment for brain metastases from breast cancer and is associated with a low complication rate.