title: Clinical implementation of a Monte Carlo based treatment plan QA platform for validation of Cyberknife and Tomotherapy treatments.
abstract: OBJECTIVE
  The main focus of the current paper is the clinical implementation of a Monte Carlo based platform for treatment plan validation for Tomotherapy and Cyberknife, without adding additional tasks to the dosimetry department.
  
  
  METHODS
  The Monte Carlo platform consists of C++ classes for the actual functionality and a web based GUI that allows accessing the system using a web browser. Calculations are based on BEAMnrc/DOSXYZnrc and/or GATE and are performed automatically after exporting the dicom data from the treatment planning system. For Cyberknife treatments of moving targets, the log files saved during the treatment (position of robot, internal fiducials and external markers) can be used in combination with the 4D planning CT to reconstruct the actually delivered dose. The Monte Carlo platform is also used for calculation on MRI images, using pseudo-CT conversion.
  
  
  RESULTS
  For Tomotherapy treatments we obtain an excellent agreement (within 2%) for almost all cases. However, we have been able to detect a problem regarding the CT Hounsfield units definition of the Toshiba Large Bore CT when using a large reconstruction diameter. For Cyberknife treatments we obtain an excellent agreement with the Monte Carlo algorithm of the treatment planning system. For some extreme cases, when treating small lung lesions in low density lung tissue, small differences are obtained due to the different cut-off energy of the secondary electrons.
  
  
  CONCLUSIONS
  A Monte Carlo based treatment plan validation tool has successfully been implemented in clinical routine and is used to systematically validate all Cyberknife and Tomotherapy plans.
authors.affiliation: Department of Medical Physics, Centre Oscar Lambret and University Lille 1, France. Electronic address: n-reynaert@o-lambret.fr.
authors.forename: N
authors.initials: N
authors.lastname: Reynaert
authors.affiliation: Department of Medical Physics, Centre Oscar Lambret and University Lille 1, France.
authors.forename: B
authors.initials: B
authors.lastname: Demol
authors.affiliation: Department of Medical Physics, Centre Oscar Lambret and University Lille 1, France.
authors.forename: M
authors.initials: M
authors.lastname: Charoy
authors.affiliation: Department of Medical Physics, Centre Oscar Lambret and University Lille 1, France.
authors.forename: S
authors.initials: S
authors.lastname: Bouchoucha
authors.affiliation: Department of Medical Physics, Centre Oscar Lambret and University Lille 1, France.
authors.forename: F
authors.initials: F
authors.lastname: Crop
authors.affiliation: Department of Medical Physics, Centre Oscar Lambret and University Lille 1, France.
authors.forename: A
authors.initials: A
authors.lastname: Wagner
authors.affiliation: Department of Medical Physics, Centre Oscar Lambret and University Lille 1, France.
authors.forename: T
authors.initials: T
authors.lastname: Lacornerie
authors.affiliation: Department of Medical Physics, Centre Oscar Lambret and University Lille 1, France.
authors.forename: F
authors.initials: F
authors.lastname: Dubus
authors.affiliation: Department of Medical Physics, Centre Oscar Lambret and University Lille 1, France.
authors.forename: E
authors.initials: E
authors.lastname: Rault
authors.affiliation: Department of Medical Physics, Centre Oscar Lambret and University Lille 1, France.
authors.forename: P
authors.initials: P
authors.lastname: Comte
authors.affiliation: Department of Medical Physics, Centre Oscar Lambret and University Lille 1, France.
authors.forename: R
authors.initials: R
authors.lastname: Cayez
authors.affiliation: Department of Medical Physics, Centre Oscar Lambret and University Lille 1, France.
authors.forename: C
authors.initials: C
authors.lastname: Boydev
authors.affiliation: Academic Department of Radiation Oncology, Centre Oscar Lambret, and University Lille 2, France.
authors.forename: D
authors.initials: D
authors.lastname: Pasquier
authors.affiliation: Academic Department of Radiation Oncology, Centre Oscar Lambret, and University Lille 2, France.
authors.forename: X
authors.initials: X
authors.lastname: Mirabel
authors.affiliation: Academic Department of Radiation Oncology, Centre Oscar Lambret, and University Lille 2, France.
authors.forename: E
authors.initials: E
authors.lastname: Lartigau
authors.affiliation: Department of Medical Physics, Centre Oscar Lambret and University Lille 1, France.
authors.forename: T
authors.initials: T
authors.lastname: Sarrazin
mesh_terms: D000465:Algorithms; D055592:Biophysical Phenomena; D003198:Computer Simulation; D005260:Female; D056973:Four-Dimensional Computed Tomography; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009010:Monte Carlo Method; D011786:Quality Control; D016634:Radiosurgery / Q000592:standards* / Q000706:statistics & numerical data*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000592:standards* / Q000706:statistics & numerical data*; D050397:Radiotherapy, Intensity-Modulated / Q000592:standards* / Q000706:statistics & numerical data*; D012984:Software
keywords: Delivered dose; Monte Carlo; QA; Treatment planning