title: Patterns of failure after concurrent bevacizumab and hypofractionated stereotactic radiation therapy for recurrent high-grade glioma.
abstract: OBJECTIVE
  Concurrent bevacizumab with hypofractionated stereotactic radiation therapy (HSRT) is safe and effective for the treatment of recurrent high-grade gliomas (HGG). The objective of this study was to characterize the patterns of failure after this treatment regimen.
  
  
  METHODS
  Twenty-four patients with recurrent enhancing HGG were previously treated on an institutional review board-approved protocol of concurrent bevacizumab and reirradiation. Patients received 30 Gy in 5 fractions to the recurrent tumor with HSRT. Brain magnetic resonance imaging (MRI) was performed every 2 cycles, and bevacizumab was continued until clinical or radiographic tumor progression according to the criteria of Macdonald et al. MRI at the time of progression was fused to the HSRT treatment plan, and the location of recurrence was classified on the basis of volume within the 95% isodose line. Outcomes based on patient characteristics, tumor grade, recurrence pattern, and best response to treatment were analyzed by the Kaplan-Meier method.
  
  
  RESULTS
  Twenty-two patients experienced either clinical or radiographic progression. Recurrent tumor was enhancing in 15 (71.4%) and nonenhancing in 6 (28.6%) patients. Eleven patients (52.4%) had recurrence within the radiation field, 5 patients (23.8%) had marginal recurrence, and 5 patients had recurrence outside the radiation field. Pattern of enhancement and location of failure did not correlate with overall survival or progression-free survival. Radiographic response was the only variable to significantly correlate with progression-free survival.
  
  
  CONCLUSIONS
  Despite the promising initial response seen with the addition of HSRT to bevacizumab as salvage treatment for recurrent HGG, approximately half of patients ultimately still experience failure within the radiation field. The rate of local failure with the addition of HSRT seems to be lower than that seen with bevacizumab alone in the salvage setting. Our data underscore the radioresistance of HGG and the need for better salvage treatments.
authors: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York, USA.
authors: Lauren Q
authors: LQ
authors: Shapiro
authors: Kathryn
authors: K
authors: Beal
authors: Anuj
authors: A
authors: Goenka
authors: Sasan
authors: S
authors: Karimi
authors: Fabio M
authors: FM
authors: Iwamoto
authors: Yoshiya
authors: Y
authors: Yamada
authors: Zhigang
authors: Z
authors: Zhang
authors: Andrew B
authors: AB
authors: Lassman
authors: Lauren E
authors: LE
authors: Abrey
authors: Philip H
authors: PH
authors: Gutin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D000068258:Bevacizumab; D001932:Brain Neoplasms / Q000175:diagnosis / Q000517:prevention & control / Q000628:therapy*; D003131:Combined Modality Therapy / Q000379:methods; D018450:Disease Progression; D005260:Female; D005910:Glioma / Q000175:diagnosis / Q000517:prevention & control / Q000628:therapy*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000517:prevention & control / Q000628:therapy*; D016634:Radiosurgery / Q000379:methods*; D012189:Retrospective Studies; D017211:Treatment Failure
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab