title: Radiosurgery for brainstem metastases with and without whole brain radiotherapy: clinical series and literature review.
abstract: OBJECTIVE
  The objective of this study was to investigate outcomes for patients with brainstem metastases treated with stereotactic radiosurgery (SRS).
  
  
  METHODS
  Patients with brainstem metastases treated with SRS between April 2006 and June 2012 were identified from a prospective database. Patient and treatment-related factors were recorded. Kaplan-Meier analysis was used to calculate survival and freedom from local and distant brain progression. Univariate and multivariate Cox regression was used to identify factors important for overall survival.
  
  
  RESULTS
  In total, 44 patients received SRS for 48 brainstem metastases of whom 33 (75 %) also received whole brain radiotherapy (WBRT): 23 patients (52 %) WBRT prior to SRS, 6 (13.6 %) WBRT concurrently with SRS and 4 (9.0 %) WBRT after SRS. Eight patients received a second course of WBRT at further progression. Median target volume was 1.33 cc (range 0.04-12.17) and median prescribed marginal dose was 15 Gy (range 10-22). There were four cases of local failure, and 6-month and 1-year freedom from local failure was 84.6 and 76.9 %, respectively. Median overall survival (OS) was 5.4 months. There were four cases of radionecrosis, 2 (4.8 %) of which were symptomatic. The absence of external beam brain radiotherapy (predominantly WBRT) showed a trend towards improved OS on univariate analysis. Neither local nor distant brain failure significantly impacted OS.
  
  
  CONCLUSIONS
  This retrospective series of patients treated with SRS for brainstem metastases, largely in combination with at least one course of WBRT, demonstrates that this approach is safe and results in good local control. In this cohort, no variables significantly impacted OS, including intracranial control.
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre/University of Toronto, 610 University Avenue, Toronto, ON M5G 2M9 Canada.
authors.forename: Louise
authors.initials: L
authors.lastname: Murray
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre/University of Toronto, 610 University Avenue, Toronto, ON M5G 2M9 Canada.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Menard
authors.affiliation: Division of Neurosurgery, University of Toronto, Toronto Western Hospital, Toronto, ON Canada.
authors.forename: Gelareh
authors.initials: G
authors.lastname: Zadeh
authors.affiliation: Division of Neurosurgery, University of Toronto, Toronto Western Hospital, Toronto, ON Canada.
authors.forename: Karolyn
authors.initials: K
authors.lastname: Au
authors.affiliation: Division of Neurosurgery, University of Toronto, Toronto Western Hospital, Toronto, ON Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Bernstein
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre/University of Toronto, 610 University Avenue, Toronto, ON M5G 2M9 Canada.
authors.forename: Barbara-Ann
authors.initials: BA
authors.lastname: Millar
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre/University of Toronto, 610 University Avenue, Toronto, ON M5G 2M9 Canada.
authors.forename: Normand
authors.initials: N
authors.lastname: Laperriere
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre/University of Toronto, 610 University Avenue, Toronto, ON M5G 2M9 Canada.
authors.forename: Caroline
authors.identifier: 0000-0002-9662-1519
authors.initials: C
authors.lastname: Chung
keywords: Brain metastases; Brainstem metastases; Stereotactic radiosurgery; Whole brain radiotherapy