Clinical Outcome of Stereotactic Radiosurgery for Central Nervous System Metastases From Renal Cell Carcinoma

The best method for treating CNS metastases from renal cell cancer (RCC) is unknown. A retrospective analysis of 166 patients with CNS metastases from RCC treated at Cleveland Clinic between 1996-2010 showed that excellent local control can be obtained with stereotactic radiosurgery, making this a preferred modality for treating patients who have a limited number of CNS metastases. Background: Current treatment modalities for central nervous system (CNS) metastases from renal cell cancer (RCC) include surgical resection, stereotactic radiosurgery (SRS), and whole-brain radiotherapy. Existing studies describing treatment outcomes for CNS metastases include multiple tumor types and thus provide little insight into how RCC CNS metastases respond to these modalities. Materials and Methods: RCC patients with brain metastases treated with SRS at the Cleveland Clinic between 1996 and 2010 were retrospectively identified. Radiosurgery and systemic therapy characteristics were recorded. Patients were followed up radiographically at 1 to 2 months after radiosurgery and every 3 to 6 months thereafter with magnetic resonance imaging scans. Results: Of the 166 patients identified, local control was obtained in 90% of patients. In 38% of patients there were additional distant CNS metastases at a median of 12.8 months (95% CI, 8.5-21.1) after SRS. The median time to progression (either local or distant) was estimated to be 9.9 months (95% CI, 5.9-12.9). Higher (> 2.5) RCC-specific graded prognostic assessment (GPA) score was the only factor examined that was found to be a significant prognostic factor for improved outcome (P = .02); however, there was some suggestion that a single target lesion (P = .07) and age >= 60 years (P = .07) may also be associated with better CNS control. Conclusion: Stereotactic radiosurgery for a limited number of CNS metastases from RCC is associated with excellent local control and is an effective if not preferred treatment modality.