title: [Determination of the human tissue interaction parameters for Monte Carlo dose calculations in radiotherapy].
abstract: BACKGROUND
  Monte Carlo dose calculation techniques for clinical photon and electron beams potentially predict the dose with an accuracy of better than +/- 2%. However, to achieve this precision, knowledge of the interaction properties in each volume element is essential.
  
  
  METHODS
  In the present paper a method for mass density to total cross section conversion is described. This method is based on a detailed analysis of the interaction data for body tissues (ICRU Report 46) and allows the conversion without knowing the atomic composition.
  
  
  RESULTS
  The analysis resulted in various fit functions allowing the calculation of interaction parameters for arbitrary materials using the corresponding cross sections in water.
  
  
  CONCLUSIONS
  Together with standard procedures to calculate mass densities from a given CT number distribution, the method represents an effective and accurate algorithm to determine photon interaction coefficients, electron stopping powers as well as electron scatter parameters.
authors.affiliation: Abteilung für Medizinische Physik, Universitätsklinikum Tübingen. msfippel@med.uni-tuebingen.de
authors.forename: M
authors.initials: M
authors.lastname: Fippel
authors.forename: F
authors.initials: F
authors.lastname: Nüsslin
mesh_terms: D003661:Decision Support Techniques; D006801:Humans; D009010:Monte Carlo Method; D011879:Radiotherapy Dosage