title: Prognostic factors for survival and radiation necrosis after stereotactic radiosurgery alone or in combination with whole brain radiation therapy for 1-3 cerebral metastases.
abstract: BACKGROUND
  In the present study factors affecting survival and toxicity in cerebral metastasized patients treated with stereotactic radiosurgery (SRS) were analyzed with special focus on radiation necrosis.
  
  
  METHODS
  340 patients with 1-3 cerebral metastases having been treated with SRS were retrospectively analyzed. Radiation necrosis was diagnosed by MRI und PET imaging. Univariate and multivariate analysis using a Cox proportional hazards regression model and log-rank test were performed to determine the prognostic value of treatment-related and individual factors for outcome and SRS-related complications.
  
  
  RESULTS
  Median overall survival was 282 days and median follow-up 721 days. 44% of patients received WBRT during the course of disease. Concerning univariate analysis a significant difference in overall survival was found for Karnofsky Performance Status (KPS ≤ 70: 122 days; KPS > 70: 342 days), for RPA (recursive partitioning analysis) class (RPA class I: 1800 days; RPA class II: 281 days; RPA class III: 130 days), irradiated volume (≤2.5 ml: 354 days; > 2.5 ml: 234 days), prescribed dose (≤18 Gy: 235 days; > 18 Gy: 351 days), gender (male: 235 days; female: 327 days) and whole brain radiotherapy (+WBRT: 341 days/-WBRT: 231 days). In multivariate analysis significance was confirmed for KPS, RPA class and gender. MRI and clinical symptoms suggested radiation necrosis in 21 patients after SRS +/- whole brain radiotherapy (WBRT). In five patients clinically relevant radiation necrosis was confirmed by PET imaging.
  
  
  CONCLUSIONS
  SRS alone or in combination with WBRT represents a feasible option as initial treatment for patients with brain metastases; however a significant subset of patients may develop neurological complications. Performance status, RPA class and gender were identified to predict improved survival in cerebral metastasized patients.
authors.forename: Lars Hendrik
authors.initials: LH
authors.lastname: Schüttrumpf
authors.forename: Maximilian
authors.initials: M
authors.lastname: Niyazi
authors.forename: Silke Birgit
authors.initials: SB
authors.lastname: Nachbichler
authors.forename: Farkhad
authors.initials: F
authors.lastname: Manapov
authors.forename: Nathalie
authors.initials: N
authors.lastname: Jansen
authors.forename: Axel
authors.initials: A
authors.lastname: Siefert
authors.affiliation: Department of Radiation Oncology, University of Munich, Marchioninistr 15, Munich 81377, Germany. claus.belka@med.uni-muenchen.de.
authors.forename: Claus
authors.initials: C
authors.lastname: Belka
mesh_terms: D000368:Aged; D001932:Brain Neoplasms / Q000401:mortality* / Q000532:radiotherapy / Q000556:secondary / Q000601:surgery; D003131:Combined Modality Therapy; D016371:Cranial Irradiation / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D009367:Neoplasm Staging; D009369:Neoplasms / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D011379:Prognosis; D011832:Radiation Injuries / Q000209:etiology / Q000401:mortality*; D016634:Radiosurgery / Q000009:adverse effects*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*; D012189:Retrospective Studies; D015996:Survival Rate