title: The impact of peer review of volume delineation in stereotactic body radiation therapy planning for primary lung cancer: a multicenter quality assurance study.
abstract: BACKGROUND
  Although the value of peer review is increasingly recognized, there is little research documenting its impact in the setting of stereotactic body radiation therapy (SBRT) for lung cancer. This study determines the dosimetric effect of peer review of tumor and normal tissue contouring in lung SBRT planning.
  
  
  METHODS
  Forty anonymized lung SBRT plans were retrospectively evaluated post treatment. Each plan was independently reviewed by two to three radiation oncologists using established institutional guidelines. For each structure, reviewers recorded recommendations for "no change," "minor change," "major change," or "missing contour" and provided a modified or new contour as needed. Dose-volume histograms were analyzed for dosimetric violations.
  
  
  RESULTS
  Among 472 contoured structures evaluated, recommendations from peer review were 107 major change (23%), 176 minor change (37%), 157 no change (33%), and 32 missing (7%). Common major changes involved the skin (n = 20), heart (n = 18), and proximal bronchial tree (n = 15). Dose constraints were not achieved for 25 new or recontoured structures (5%), of which 17 involved the planning target volume (PTV). Among cases with PTV violations, the mean prescription dose coverage to the modified PTVs was 90%, compared with the protocol standard of greater than or equal to 95% coverage. The remaining violations involved the ribs (n = 5), spinal canal (n = 2), and heart (n = 1).
  
  
  CONCLUSIONS
  Peer review of structure contouring resulted in significant changes in lung SBRT plans. Recontouring of several plans revealed violations of dose limits, most often involving inadequate PTV coverage. Peer review, especially of target volume delineation, is warranted to improve consistency and quality in lung SBRT planning.
authors.affiliation: *Department of Radiation Oncology, British Columbia Cancer Agency, Vancouver Centre, Vancouver, British Columbia, Canada; †Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada; ‡Department of Oncology, Saint John Regional Hospital, Saint John, New Brunswick, Canada; §Department of Radiation Oncology, British Columbia Cancer Agency Fraser Valley Centre, Surrey, British Columbia, Canada; ‖Department of Radiation Oncology, British Columbia Cancer Agency Vancouver Island Centre, Victoria, British Columbia, Canada; ¶Department of Radiation Oncology, Cancer Care Manitoba, Winnipeg, Manitoba, Canada; and #British Columbia Cancer Agency Centre for the North, Prince George, British Columbia, Canada.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Lo
authors.forename: Mitchell
authors.initials: M
authors.lastname: Liu
authors.forename: Elisa
authors.initials: E
authors.lastname: Chan
authors.forename: Chad
authors.initials: C
authors.lastname: Lund
authors.forename: Pauline T
authors.initials: PT
authors.lastname: Truong
authors.forename: Shaun
authors.initials: S
authors.lastname: Loewen
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Cao
authors.forename: Devin
authors.initials: D
authors.lastname: Schellenberg
authors.forename: Hannah
authors.initials: H
authors.lastname: Carolan
authors.forename: Tanya
authors.initials: T
authors.lastname: Berrang
authors.forename: Jonn
authors.initials: J
authors.lastname: Wu
authors.forename: Eric
authors.initials: E
authors.lastname: Berthelet
authors.forename: Robert
authors.initials: R
authors.lastname: Olson
mesh_terms: D000465:Algorithms; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology* / Q000601:surgery; D015588:Observer Variation; D058958:Organs at Risk / Q000528:radiation effects; D010380:Peer Review; D011379:Prognosis; D011785:Quality Assurance, Health Care; D016634:Radiosurgery; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated; D012189:Retrospective Studies