title: Propensity-score matched pair comparison of whole brain with simultaneous in-field boost radiotherapy and stereotactic radiosurgery.
abstract: OBJECTIVE
  To compare lesional stereotactic radiosurgery to whole brain (WBRT) radiotherapy with simultaneous in-field boost for brain metastases in terms of overall survival.
  
  
  METHODS
  A retrospective review was performed on two institutional databases of 500 patients diagnosed with brain metastatic disease who received either stereotactic radiosurgery (SRS, n = 381) or whole brain with simultaneous in-field boost radiotherapy (SIB, n = 119), between 2002 and 2011. Propensity-score matching was utilized to obtain two groups with similar known prognostic factor characteristics. Kaplan-Meier and univariable/multivariable Cox modeling were conducted to assess the treatment impact on overall survival (OS).
  
  
  RESULTS
  Propensity-score matching created a matched cohort of 178 patients (89 SRS/SIB) with similar baseline characteristics. Multivariable analysis demonstrated that presence/absence of systemic metastases, patient age, tumor volume, and presence/absence of active primary were found to be more predictive of OS than treatment assignment (p = 0.38). SIB was associated with reduced intracranial failure likely due to the WBRT component of the treatment (HR 0.36, p<0.001).
  
  
  CONCLUSIONS
  Adjusting for other predictive factors, treatment with either SRS or SIB did not result in any statistically significant difference in OS; however, observed intracranial failure was different due to the use of WBRT in the SIB cohort.
authors.affiliation: London Health Sciences Centre, London, Canada. george.rodrigues@lhsc.on.ca
authors.forename: George
authors.initials: G
authors.lastname: Rodrigues
authors.forename: Jaap
authors.initials: J
authors.lastname: Zindler
authors.forename: Andrew
authors.initials: A
authors.lastname: Warner
authors.forename: Glenn
authors.initials: G
authors.lastname: Bauman
authors.forename: Suresh
authors.initials: S
authors.lastname: Senan
authors.forename: Frank
authors.initials: F
authors.lastname: Lagerwaard
mesh_terms: D001932:Brain Neoplasms / Q000401:mortality / Q000532:radiotherapy / Q000556:secondary* / Q000601:surgery; D016371:Cranial Irradiation; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D016016:Proportional Hazards Models; D016634:Radiosurgery; D012189:Retrospective Studies