Linear accelerator stereotactic radiosurgery for metastatic brain tumors: 17 years of experience at the University of Florida

OBJECTIVE: To review one of the largest single-institution experiences treating metastatic brain disease with stereotactic radiosurgery. METHODS: We performed a retrospective analysis of 619 patients who underwent linear accelerator-based stereotactic radiosurgery for 1569 brain metastases between May 1989 and February 2006. Patient characteristics and treatment parameters were obtained prospectively. Patients were followed up at regular intervals clinically and with imaging studies to document local control, regional control, and survival. Cox proportional hazards analysis was performed using SAS version 9.1 software (SAS Institute, Cary, NC). RESULTS: Median actuarial survival was 7.9 months. 1- and 2-year actuarial survival probabilities were 0.36 and 0. 14, respectively. Radiation Therapy Oncology Group Recursive Partitioning Analysis Class I or II was associated with improved survival, but the difference between the two was insignificant. Female sex, younger age, higher Karnofsky performance status, controlled primary tumor, absence of systemic metastases, asynchronous presentation of brain metastasis, fewer brain metastases, smaller total volume of brain metastases, surgery prior to radiosurgery, and multiple radiosurgical treatments were also associated with improved survival. Melanoma metastasis was associated with impaired survival. Local control was achieved in 843% of all lesions treated. 1- and 2-year actuarial local control probabilities were 0.82 and 0.72, respectively. Whole brain radiation therapy prior to radiosurgery was associated with improved regional control. CONCLUSIONS: Linear accelerator-based stereotactic radiosurgery is a safe and effective treatment for patients with metastatic brain tumors. Selection of patients who are likely to benefit most from radiosurgery is complex and treatment decisions should be based on the entire clinical picture.