Young Kwok MD, Presenter: Nothing to Disclose

To report the long-term experience with gamma knife stereotactic radiosurgery (GK-SRS) in the management of breast cancer patients with brain metastasis.

From 1995 to 2005, 75 patients with a total of 162 brain lesions were treated with GK-SRS at the University of Maryland. The median follow-up, age, and KPS were 13.6 months (0.4-75.7 months), 53.5 years (23-81 years), and 90 (40-100), respectively. The median number of lesions treated with GK-SRS was 2 (1-8 lesions).Whole brain radiation therapy (WBRT) was administered to 53 (70.7%) patients. The median WBRT dose was 37.5 Gy (30.0-45.0 Gy). The factors included in the univariate and multivariate analyses for intracranial progression free survival (PFS) and overall survival (OS) were age, Karnofsky Performance Status (KPS), estrogen receptor status, Her-2-neu status, number of intracranial lesions, and RTOG RPA class.

Median PFS and OS from GK-SRS were 5.3 months (0.4-33.2 months) and 8.1 months (0.4-75.7 months), respectively. The 6, 12, and 24 month actuarial PFS were 47.8%, 24.9%, and 9.6% respectively. The 6, 12, and 24 month actuarial OS were 60.7%, 39.1%, and 18.1% respectively. The tumor local control after WBRT and GK-SRS was 87.7%. Eleven percent of patients experienced radiation necrosis. Forty-seven (62.7%) patients had neurological symptoms prior to gamma knife treatment. Of these, 16 (34%) patients experienced significant symptomatic improvement or resolution. Univariate and multivariate analysis did not reveal any significant prognostic factor in question associated with PFS or OS.

This large study demonstrates that GK-SRS can provide significant symptomatic relief with acceptable complication rates. However, despite aggressive intracranial therapy, patients experienced survival that is significantly worse than reported in the literature for metastatic breast cancer patients without brain metastasis. Therefore, more research is required to improve the survival of breast cancer patients with this poor prognostic feature.

Kwok, Y, Long-term Outcome of Breast Cancer Patients with Brain Metastasis Treated with Gamma Knife Stereotactic Radiosurgery.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/8001914.html