%0 Generic
%A Dörner, Edgardo
%D 2012
%F heidok:14320
%K Medical physics  General theory and mathematical aspects  Monte Carlo methods  Collimation  Simulation    
%R 10.11588/heidok.00014320
%T Development and Validation of a Multi-Leaf Collimator Component Module Using a Modified EGSnrc Platform for Monte Carlo Simulations
%U https://archiv.ub.uni-heidelberg.de/volltextserver/14320/
%X A new component module (CM) named MMLC was developed for the Monte Carlo code BEAMnrc. It models the geometry and the dosimetrical characteristics of the add-on miniature multileaf collimator ModuLeaf (MRC Systems GmbH, Heidelberg, Germany, now part of Siemens, Erlangen, Germany). The new component module is partly based on the existing CM called DYNVMLC. The development was performed using a modified EGSnrc platform which enables to work in the Microsoft Visual Studio environment.  In order to validate the new CM, the PRIMUS linac with 6 MV x-rays (Siemens OCS, Concord, California, USA) equipped with the ModuLeaf mini MLC was modeled. Validation was performed by two methods: (a) a ray-tracing method to check the correct geometry of the MLC, and (b) a comparison of calculated and measured results of the following dosimetrical parameters: output factors, dose profiles, field edge position, penumbra, MLC interleaf leakage and transmission values. An excellent agreement was found for all parameters. It was in particular also found that the relationship between leaf position and field edge depending on the shape of leaf ends can be investigated with a higher accuracy by this new calculation tool than by measurements further demonstrating the usefulness of the new CM.