title: Linac radiosurgery versus whole brain radiotherapy for brain metastases. A survival comparison based on the RTOG recursive partitioning analysis.
abstract: OBJECTIVE
  For patients with inoperable brain metastases, whole brain radiotherapy (WBRT) has been the standard treatment for decades. Radiosurgery is an effective alternative strategy, but has failed to show a substantial survival benefit so far. The prognostic factors derived from the RTOG recursive partitioning analysis (RPA) provide a framework that allows a nonrandomized comparison of the two modalities.
  
  
  METHODS
  From 1991 to 1998, 117 patients with one to three previously untreated cerebral metastases underwent single-dose linac radiosurgery (median dose 20 Gy) without adjuvant WBRT. After radiosurgery, 26/117 patients (22%) had salvage WBRT, radiosurgery or neurosurgical resection of recurrent (4/117) and/or new (24/117) metastases. Survival of these patients was compared to a historical group of 138 patients with one to three lesions treated by WBRT (30-36 Gy/3-Gy fractions) from 1978 to 1991; only nine of these patients (7%) had salvage WBRT. All patients were classified into the three RPA prognostic classes based on age, performance score, and presence of extracranial tumor manifestations.
  
  
  RESULTS
  In RPA class I (Karnofsky performance score > or = 70, primary tumor controlled, no other metastases, age < 65 years), radiosurgery resulted in a median survival of 25.4 months (n = 23, confidence interval [CI] 5.8-45.0) which was significantly longer than for WBRT (n = 9, 4.7 months, CI 3.8-5.5; p < 0.0001). In RPA class III (Karnofsky performance score < 70), no significant difference in survival between radiosurgery (n = 20, 4.2 months, CI 3.2-5.3) and WBRT (n = 68, 2.5 months, CI 2.2-2.8) was found. In RPA class II (all other patients), radiosurgery produced a small, but significant survival advantage (radiosurgery: n = 74, 5.9 months, CI 3.2-8.5, WBRT: n = 61, 4.1 months, CI 3.4-4.9; p < 0.04).
  
  
  CONCLUSIONS
  Radiosurgery in patients with one to three cerebral metastases results in a substantial survival benefit only in younger patients with a low systemic tumor burden when compared to WBRT alone. It cannot be excluded that this effect is partially caused by the available salvage options after radiosurgery.
authors.affiliation: Department of Radiation Oncology, University of Cologne, Germany. Martin.Kocher@medizin.uni-koeln.de
authors.forename: Martin
authors.initials: M
authors.lastname: Kocher
authors.forename: Mohammad
authors.initials: M
authors.lastname: Maarouf
authors.forename: Mark
authors.initials: M
authors.lastname: Bendel
authors.forename: Juergen
authors.initials: J
authors.lastname: Voges
authors.forename: Rolf-Peter
authors.initials: RP
authors.lastname: Müller
authors.forename: Volker
authors.initials: V
authors.lastname: Sturm
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000401:mortality* / Q000532:radiotherapy* / Q000556:secondary; D018572:Disease-Free Survival; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009382:Neoplasms, Unknown Primary / Q000401:mortality* / Q000532:radiotherapy*; D011379:Prognosis; D016634:Radiosurgery / Q000706:statistics & numerical data*; D020266:Radiotherapy, Conformal / Q000706:statistics & numerical data*; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D016879:Salvage Therapy / Q000706:statistics & numerical data*; D013534:Survival; D016019:Survival Analysis; D016896:Treatment Outcome