Resecting the dominant lesion: Patient outcomes after surgery and radiosurgery vs stand-alone radiosurgery in the setting of multiple brain metastases.

ABSTRACT

BACKGROUND: Brain metastases are the most common central nervous system (CNS) tumors, occurring in 300,000 people per year in the US. While there are immediate local benefits to surgical resection for dominant lesions, including reduction of tumor burden and edema, the survival benefits of surgical resection, over radiosurgery, remains unclear. METHODS: The University of Pennsylvania Health System database was retrospectively reviewed for patients presenting with multiple brain metastases from 1/1/16-8/31/18 with one dominant lesion > 2 cm in diameter, who underwent initial treatment with either resection of the dominant lesion or Gamma Knife radiosurgery (GKS). Inclusion criteria were age > 18, > 1 brain metastasis, and presence of a dominant lesion (>2 cm). We analyzed factors associated with mortality. RESULTS: 129 patients were identified (surgery=84, GKS=45). The median number of intracranial metastases was 3 (IQR 2-5). The median diameter of the largest lesion was 31 mm (IQR 25-38) in the surgery group vs 21 mm (IQR 20-24) in the GKS group (p < 0.001). Mortality did not differ between surgery and GKS patients (69.1% vs 77.8%, p = 0.292). In a multivariate survival analysis, there was no difference in mortality between the surgery and GKS cohorts (aHR 1.35, 95% CI 0.74-2.45 p = 0.32). Pre-operative KPS (aHR 0.97, 95% CI 0.95-0.99, p = 0.004), CNS radiotherapy (aHR 0.33, 95% CI 0.19-0.56 p < 0.001), chemotherapy (aHR 0.27, 95% CI 0.15-0.47, p < 0.001), and immunotherapy (aHR 0.41, 95% CI 0.25-0.68, p = 0.001) were associated with decreased mortality. CONCLUSION: In our institution, patients with multiple brain metastases and one symptomatic dominant lesion demonstrated similar survival after GKS when compared with up-front surgical resection of the dominant lesion.