title: Evaluation of volumetric modulated arc therapy (VMAT) with Oncentra MasterPlan® for the treatment of head and neck cancer.
abstract: BACKGROUND
  Several comparison studies have shown the capability of VMAT to achieve similar or better plan quality as IMRT, while reducing the treatment time. The experience of VMAT in a multi vendor environment is limited. We compared the plan quality and performance of VMAT to IMRT and we investigate the effects of varying various user-selectable parameters.
  
  
  METHODS
  IMRT, single arc VMAT and dual arc VMAT were compared for four different head-and-neck tumors. For VMAT, the effect of varying gantry angle spacing and treatment time on the plan quality was investigated. A comparison of monitor units and treatment time was performed.
  
  
  RESULTS
  IMRT and dual arc VMAT achieved a similar plan quality, while single arc could not provide an acceptable plan quality. Increasing the number of control points does not improve the plan quality. Dual arc VMAT delivery time is about 30% of IMRT delivery time.
  
  
  CONCLUSIONS
  Dual arc VMAT is a fast and accurate technique for the treatment of head and neck cancer. It applies similar number of MUs as IMRT, but the treatment time is strongly reduced, maintaining similar or better dose conformity to the PTV and OAR sparing.
authors.affiliation: Department of Radiotherapy, Regensburg University Medical Center, Regensburg, Germany. judith.alvarez-moret@klinik.uni-regensburg.de
authors.forename: Judith
authors.initials: J
authors.lastname: Alvarez-Moret
authors.forename: Fabian
authors.initials: F
authors.lastname: Pohl
authors.forename: Oliver
authors.initials: O
authors.lastname: Koelbl
authors.forename: Barbara
authors.initials: B
authors.lastname: Dobler
mesh_terms: D000465:Algorithms; D002277:Carcinoma / Q000532:radiotherapy*; D005240:Feasibility Studies; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D007089:Image Enhancement; D011874:Radiometry; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000295:instrumentation / Q000379:methods*; D013997:Time Factors