title: GliaSite brachytherapy boost as part of initial treatment of glioblastoma multiforme: a retrospective multi-institutional pilot study.
abstract: OBJECTIVE
  To report on a retrospective analysis of the cumulative experience from eight institutions using the GliaSite Radiotherapy System as a brachytherapy boost in the initial management of glioblastoma multiforme.
  
  
  METHODS
  Eight institutions provided data on 20 patients with histologically proven glioblastoma multiforme with a median age of 59 years (range, 39-76) and median Karnofsky performance scale of 80 (range, 50-100). After maximal surgical debulking, patients were treated with GliaSite brachytherapy to a median dose of 50 Gy, followed by external beam radiotherapy to a median dose of 60 Gy (range, 46-60 Gy), for a cumulative dose escalation of 110 Gy (range, 84-130 Gy).
  
  
  RESULTS
  The average survival for this study population was 11.4 months (range, 4-29). When the patients' survival was compared with that of historical controls according to their Radiation Therapy Oncology Group recursive partitioning analysis class, the average survival was increased by 3 months (95% confidence interval, 0.23-4.9) corresponding to a 43% increase (p = 0.033). Three patients (14%) experienced Radiation Therapy Oncology Group Grade 3 central nervous system toxicity. Of the treatment failures, 50% were >2 cm from the edge of the balloon.
  
  
  CONCLUSIONS
  The results of this analysis have demonstrated that dose escalation (>100 Gy) with GliaSite is well tolerated and associated with minimal toxicity. Local control improved with the use of GliaSite brachytherapy. The putative survival advantage seen in this study needs to be interpreted with caution; nevertheless, the data provide sufficient justification to investigate the potential role of radiation dose escalation in conjunction with GliaSite in the initial treatment of glioblastoma multiforme.
authors.affiliation: Department of Radiation Oncology, University of Arizona, Tucson, AZ, USA.
authors.forename: James
authors.initials: J
authors.lastname: Welsh
authors.forename: Abhay
authors.initials: A
authors.lastname: Sanan
authors.forename: Arash J
authors.initials: AJ
authors.lastname: Gabayan
authors.forename: Sylvan B
authors.initials: SB
authors.lastname: Green
authors.forename: Robert
authors.initials: R
authors.lastname: Lustig
authors.forename: Stuart
authors.initials: S
authors.lastname: Burri
authors.forename: Edmund
authors.initials: E
authors.lastname: Kwong
authors.forename: Baldassarre
authors.initials: B
authors.lastname: Stea
mesh_terms: D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000295:instrumentation* / Q000379:methods; D001932:Brain Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D005909:Glioblastoma / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D016019:Survival Analysis