Introduction: Stereotactic radiosurgery has demonstrated significant cognitive and overall survival benefit in a select group of patients with brain metastases when compared to whole brain radiation therapy (WBRT). We analyzed our initial experience using gamma knife radiosurgery (GKRS) as both an upfront modality and a postoperative adjunct in patients with brain metastases to determine safety, feasibility, and clinical impact in the community-based cancer center setting.
Methods: Recursive partitioning analysis (RPA) class I and II patients treated with GKRS for both solitary and multiple brain metastases from known solid primary sites were enrolled in a prospective clinical database from November 2011 through February 2014. Retrospective data analysis was performed to determine safety, overall survival, time to local progression, and freedom from WBRT.
Results: A total of 182 lesions in 63 patients (21% RPA class I, 79% RPA class II) were treated with GKRS during the study period. GKRS was used as a stand-alone therapy in 167 lesions (92%). Eighty four percent of our patients harbored 1-3 lesions. Common pathologies included lung (41%), breast (21%), and kidney (11%). Median overall survival was 12.3 months (95% CI: 8.1-16.5). Tumor control rates were 94% and 82% at 6- and 12-months, respectively. Freedom from WBRT was maintained in 90%, 79%, and 71% of patients at 6-, 12-, and 18-months respectively. Grade 3 toxicities were observed in 4 of 182 treatments (2.2%).
Conclusions: GKRS is safe and effective as both an initial and adjuvant treatment strategy for RPA class I and II brain metastases patients. Overall survival rates in our patient population are similar to those demonstrated in recent randomized clinical trials comparing radiosurgery alone to radiosurgery plus WBRT . This strategy can be effectively implemented and should be considered as a primary treatment paradigm in community-based cancer centers.
Patient Care: If this paradigm of treatment is more widely adopted, we anticipate improved overall survival and functional outcome in RPA class I and II patients harboring Brian metastases.
Learning Objectives: By the conclusion of this session, participants should be able to:
1) understand the utility of Gamma Knife Radiosurgery as a stand-alone treatment for multiple brain metastases.
2) realize the potential benefit on overall survival of GKRS alone in this patient population
3) consider the utility of implementing this treatment paradigm in the community setting.