title: Comparison of intensity modulated radiotherapy (IMRT) with intensity modulated particle therapy (IMPT) using fixed beams or an ion gantry for the treatment of patients with skull base meningiomas.
abstract: BACKGROUND
  To examine the potential improvement in treatment planning for patients with skull base meningioma using IMRT compared to carbon ion or proton beams with and without a gantry.
  
  
  METHODS
  Five patients originally treated with photon IMRT were selected for the study. Ion beams were chosen using a horizontal beam or an ion gantry. Intensity controlled raster scanning and the intensity modulated particle therapy mode were used for plan optimization. The evaluation included analysis of dose-volume histograms of the target volumes and organs at risk.
  
  
  RESULTS
  In comparison with carbon and proton beams only with horizontal beams, carbon ion treatment plans could spare the OARs more and concentrated on the target volumes more than proton and photon IMRT treatment plans. Using only a horizontal fixed beam, satisfactory plans could be achieved for skull base tumors.
  
  
  CONCLUSIONS
  The results of the case studies showed that using IMPT has the potential to overcome the lack of a gantry for skull base tumors. Carbon ion plans offered slightly better dose distributions than proton plans, but the differences were not clinically significant with established dose prescription concepts.
authors.affiliation: Department of Radiology, Nagoya City University Hospital, Nagoya, Japan.
authors.forename: Katsura
authors.initials: K
authors.lastname: Kosaki
authors.forename: Swantje
authors.initials: S
authors.lastname: Ecker
authors.forename: Daniel
authors.initials: D
authors.lastname: Habermehl
authors.forename: Stefan
authors.initials: S
authors.lastname: Rieken
authors.forename: Oliver
authors.initials: O
authors.lastname: Jäkel
authors.forename: Klaus
authors.initials: K
authors.lastname: Herfarth
authors.forename: Jürgen
authors.initials: J
authors.lastname: Debus
authors.forename: Stephanie E
authors.initials: SE
authors.lastname: Combs
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002244:Carbon / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007477:Ions / Q000627:therapeutic use; D008297:Male; D008577:Meningeal Neoplasms / Q000532:radiotherapy*; D008579:Meningioma / Q000532:radiotherapy*; D008875:Middle Aged; D058958:Organs at Risk / Q000528:radiation effects; D061766:Proton Therapy; D011829:Radiation Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D019292:Skull Base Neoplasms / Q000532:radiotherapy*
chemical_list: D007477:Ions; D002244:Carbon