title: Use of benchmark dose-volume histograms for selection of the optimal technique between three-dimensional conformal radiation therapy and intensity-modulated radiation therapy in prostate cancer.
abstract: OBJECTIVE
  The aim of this study was to develop and validate our own benchmark dose-volume histograms (DVHs) of bladder and rectum for both conventional three-dimensional conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT), and to evaluate quantitatively the benefits of using IMRT vs. 3D-CRT in treating localized prostate cancer.
  
  
  METHODS
  During the implementation of IMRT for prostate cancer, our policy was to plan each patient with both 3D-CRT and IMRT. This study included 31 patients with T1b to T2c localized prostate cancer, for whom we completed double-planning using both 3D-CRT and IMRT techniques. The target volumes included prostate, either with or without proximal seminal vesicles. Bladder and rectum DVH data were summarized to obtain an average DVH for each technique and then compared using two-tailed paired t test analysis.
  
  
  RESULTS
  For 3D-CRT our bladder doses were as follows: mean 28.8 Gy, v60 16.4%, v70 10.9%; rectal doses were: mean 39.3 Gy, v60 21.8%, v70 13.6%. IMRT plans resulted in similar mean dose values: bladder 26.4 Gy, rectum 34.9 Gy, but lower values of v70 for the bladder (7.8%) and rectum (9.3%). These benchmark DVHs have resulted in a critical evaluation of our 3D-CRT techniques over time.
  
  
  CONCLUSIONS
  Our institution has developed benchmark DVHs for bladder and rectum based on our clinical experience with 3D-CRT and IMRT. We use these standards as well as differences in individual cases to make decisions on whether patients may benefit from IMRT treatment rather than 3D-CRT.
authors.affiliation: Radiation Oncology, University of California Davis Medical Center, Sacramento, CA 95817, USA.
authors.forename: Chunhui
authors.initials: C
authors.lastname: Luo
authors.forename: Claus Chunli
authors.initials: CC
authors.lastname: Yang
authors.forename: Samir
authors.initials: S
authors.lastname: Narayan
authors.forename: Robin L
authors.initials: RL
authors.lastname: Stern
authors.forename: Julian
authors.initials: J
authors.lastname: Perks
authors.forename: Zelanna
authors.initials: Z
authors.lastname: Goldberg
authors.forename: Janice
authors.initials: J
authors.lastname: Ryu
authors.forename: James A
authors.initials: JA
authors.lastname: Purdy
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Vijayakumar
mesh_terms: D000328:Adult; D000465:Algorithms; D019985:Benchmarking / Q000379:methods; D020000:Decision Support Systems, Clinical; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D020266:Radiotherapy, Conformal / Q000379:methods*