The role of systemic disease status in treatment outcomes for patients with newly diagnosed brain oligometastases and treated with stereotactic radiosurgery alone

ObjectiveThe role of adjuvant whole-brain radiation therapy in the treatment of oligometastatic brain disease with stereotactic radiosurgery (SRS) is not clearly defined. Many clinicians use a systemic disease status factor to determine whether SRS alone is sufficient; however, data is limited to support this approach.MethodsWe conducted a retrospective review of patients with newly diagnosed brain metastases treated at our institution between 2005 and 2010 and identified 169 patients who were treated with SRS alone.ResultsThe overall median survival was 11.8 months (90 % CI [10.1, 14.7]) and the overall median time to brain recurrence was 7.1 months. We have observed that the primary disease status at the time of initial diagnosis is associated with worse overall survival (hazard ratio (HR) 1.7, p = 0.005), after adjusting for recursive partitioning analysis (RPA) classification, number of lesions, performance status, and prior surgery. Primary disease status is also associated with higher likelihood of CNS disease recurrence (HR 1.8, p = 0.01), after adjusting for pathology of primary disease, age, RPA classification, and number of lesions.ConclusionThese results might help clinicians with proper selection and counseling of patients regarding treatment modalities for patients with newly diagnosed brain metastases.