title: Standard fractionation intensity modulated radiation therapy (IMRT) of primary and recurrent glioblastoma multiforme.
abstract: BACKGROUND
  Intensity-modulated radiation therapy (IMRT) affords unparalleled capacity to deliver conformal radiation doses to tumors in the central nervous system. However, to date, there are few reported outcomes from using IMRT, either alone or as a boost technique, for standard fractionation radiotherapy for glioblastoma multiforme (GBM).
  
  
  METHODS
  Forty-two patients were treated with IMRT alone (72%) or as a boost (28%) after 3-dimensional conformal radiation therapy (3D-CRT). Thirty-three patients with primary disease and 9 patients with recurrent tumors were included. Thirty-four patients (81%) had surgery, with gross tumor resection in 13 patients (36%); 22 patients (53%) received chemo-radiotherapy. The median total radiation dose for all patients was 60 Gy with a range from 30.6 to 74 Gy. Standard fractions of 1.8 Gy/day to 2.0 Gy/day were utilized.
  
  
  RESULTS
  Median survival was 8.7 months, with 37 patients (88%) deceased at last contact. Nonparametric analysis showed no survival difference in IMRT-boost vs. IMRT-only groups.
  
  
  CONCLUSIONS
  While technically feasible, preliminary results suggest delivering standard radiation doses by IMRT did not improve survival outcomes in this series compared to historical controls. In light of this lack of a survival benefit and the costs associated with use of IMRT, future prospective trials are needed to evaluate non-survival endpoints such as quality of life and functional preservation. Short of such evidence, the use of IMRT for treatment of GBM needs to be carefully rationalized.
authors.affiliation: Department of Radiation Oncology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA. fullercd@uthscsa.edu
authors.forename: Clifton D
authors.initials: CD
authors.lastname: Fuller
authors.forename: Mehee
authors.initials: M
authors.lastname: Choi
authors.forename: Britta
authors.initials: B
authors.lastname: Forthuber
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Wang
authors.forename: Nancy
authors.initials: N
authors.lastname: Rajagiriyil
authors.forename: Bill J
authors.initials: BJ
authors.lastname: Salter
authors.forename: Martin
authors.initials: M
authors.lastname: Fuss
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D002490:Central Nervous System / Q000528:radiation effects*; D019583:Dose Fractionation, Radiation; D005260:Female; D005909:Glioblastoma / Q000401:mortality / Q000532:radiotherapy*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012008:Recurrence; D016896:Treatment Outcome