title: Design and evaluation of a Monte Carlo based model of an orthovoltage treatment system.
abstract: The aim of this study was to develop a flexible framework of an orthovoltage treatment system capable of calculating and visualizing dose distributions in different phantoms and CT datasets. The framework provides a complete set of various filters, applicators and x-ray energies and therefore can be adapted to varying studies or be used for educational purposes. A dedicated user friendly graphical interface was developed allowing for easy setup of the simulation parameters and visualization of the results. For the Monte Carlo simulations the EGSnrc Monte Carlo code package was used. Building the geometry was accomplished with the help of the EGSnrc C++ class library. The deposited dose was calculated according to the KERMA approximation using the track-length estimator. The validation against measurements showed a good agreement within 4-5% deviation, down to depths of 20% of the depth dose maximum. Furthermore, to show its capabilities, the validated model was used to calculate the dose distribution on two CT datasets. Typical Monte Carlo calculation time for these simulations was about 10 minutes achieving an average statistical uncertainty of 2% on a standard PC. However, this calculation time depends strongly on the used CT dataset, tube potential, filter material/thickness and applicator size.
authors.affiliation: Institute of Medical Physics and Radiation Protection - IMPS University of Applied Sciences, Gießen, Germany. Electronic address: petar.penchev@kmub.thm.de.
authors.forename: Petar
authors.initials: P
authors.lastname: Penchev
authors.affiliation: Institute of Medical Physics and Radiation Protection - IMPS University of Applied Sciences, Gießen, Germany.
authors.forename: Ulf
authors.initials: U
authors.lastname: Mäder
authors.affiliation: Institute of Medical Physics and Radiation Protection - IMPS University of Applied Sciences, Gießen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Fiebich
authors.affiliation: Institute of Medical Physics and Radiation Protection - IMPS University of Applied Sciences, Gießen, Germany; University Hospital Marburg, Department of Radiotherapy and Radiation Oncology, Philipps-University, Marburg, Germany.
authors.forename: Klemens
authors.initials: K
authors.lastname: Zink
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D015233:Models, Statistical; D009010:Monte Carlo Method; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D020266:Radiotherapy, Conformal / Q000295:instrumentation* / Q000379:methods*; D012542:Scattering, Radiation
keywords: Dosisberechnung; Monte Carlo simulations; Monte-Carlo-Simulation; Orthovolttherapie; dose calculation; orthovoltage radiation therapy