title: A multiplan treatment-planning framework: a paradigm shift for intensity-modulated radiotherapy.
abstract: OBJECTIVE
  To describe a multiplan intensity-modulated radiotherapy (IMRT) planning framework, and to describe a decision support system (DSS) for ranking multiple plans and modeling the planning surface.
  
  
  METHODS
  One hundred twenty-five plans were generated sequentially for a head-and-neck case and a pelvic case by varying the dose-volume constraints on each of the organs at risk (OARs). A DSS was used to rank plans according to dose-volume histogram (DVH) values, as well as equivalent uniform dose (EUD) values. Two methods for ranking treatment plans were evaluated: composite criteria and pre-emptive selection. The planning surface determined by the results was modeled using quadratic functions.
  
  
  RESULTS
  The DSS provided an easy-to-use interface for the comparison of multiple plan features. Plan ranking resulted in the identification of one to three "optimal" plans. The planning surface models had good predictive capability with respect to both DVH values and EUD values and generally, errors of <6%. Models generated by minimizing the maximum relative error had significantly lower relative errors than models obtained by minimizing the sum of squared errors. Using the quadratic model, plan properties for one OAR were determined as a function of the other OAR constraint settings. The modeled plan surface can then be used to understand the interdependence of competing planning objectives.
  
  
  CONCLUSIONS
  The DSS can be used to aid the planner in the selection of the most desirable plan. The collection of quadratic models constructed from the plan data to predict DVH and EUD values generally showed excellent agreement with the actual plan values.
authors.affiliation: Computer Sciences Department, University of Wisconsin, Madison, WI, USA.
authors.forename: Robert R
authors.initials: RR
authors.lastname: Meyer
authors.forename: Hao H
authors.initials: HH
authors.lastname: Zhang
authors.forename: Laura
authors.initials: L
authors.lastname: Goadrich
authors.forename: Daryl P
authors.initials: DP
authors.lastname: Nazareth
authors.forename: Leyuan
authors.initials: L
authors.lastname: Shi
authors.forename: Warren D
authors.initials: WD
authors.lastname: D'Souza
mesh_terms: D003661:Decision Support Techniques; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D010386:Pelvic Neoplasms / Q000532:radiotherapy*; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*