title: A practical approach to assess clinical planning tradeoffs in the design of individualized IMRT treatment plans.
abstract: OBJECTIVE
  To investigate the tradeoffs between organ at risk sparing and tumour coverage for IMRT treatment of lung tumours, and to develop a tool for clinical use to graphically represent these tradeoffs.
  
  
  METHODS
  For 5 patients with inoperable non-small cell lung cancer (NSCLC) different IMRT plans were generated using a standard TPS. The plans were automatically generated for a range of IMRT settings (weights and dose levels of the objective functions) and were systematically evaluated, focusing on the tradeoffs between organ at risk (OAR) dose and target coverage. A method to analyze and visualize planning tradeoffs was developed and evaluated.
  
  
  RESULTS
  Lung and oesophagus were identified as the critical organs at risk for NSCLC, the sparing of which strongly influences PTV coverage. Systematically analyzing the tradeoffs between these organs revealed that the sparing of these organs was approximately linearly related to PTV coverage parameters. Using this property, a tool was developed to graphically present the tradeoffs between the sparing of these organs at risk and the PTV coverage. The tool is an effective method to visualize the tradeoffs.
  
  
  CONCLUSIONS
  A tool was developed to assist IMRT plan design and selection. The clear presentation of the tradeoffs between OAR dose and coverage facilitates the optimization process and offers additional information to the clinician for a patient specific choice of the optimal IMRT plan.
authors.affiliation: Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, The Netherlands. R.Monshouwer@rther.umcn.nl
authors.forename: René
authors.initials: R
authors.lastname: Monshouwer
authors.forename: Aswin L
authors.initials: AL
authors.lastname: Hoffmann
authors.forename: Martina
authors.initials: M
authors.lastname: Kunze-Busch
authors.forename: Johan
authors.initials: J
authors.lastname: Bussink
authors.forename: Johannes H A M
authors.initials: JH
authors.lastname: Kaanders
authors.forename: Henk
authors.initials: H
authors.lastname: Huizenga
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000532:radiotherapy*; D004947:Esophagus / Q000528:radiation effects; D006801:Humans; D008168:Lung / Q000528:radiation effects; D008175:Lung Neoplasms / Q000532:radiotherapy*; D058958:Organs at Risk / Q000528:radiation effects; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D047368:Tumor Burden