[Verification and application of the voxel-based Monte Carlo (VMC++) electron dose module of Oncentra MasterPlan].
PURPOSE, MATERIAL AND METHODS: The dose calculation accuracy of the voxel-based Monte Carlo (VMC++) electron dose module of Oncentra MasterPlan (Nucletron B.V., Veenendaal, The Netherlands) was verified by measurements in homogeneous water phantoms.


RESULTS
Measured and calculated dose maxima on the central beam axis (calculations with 10,000-20,000 incident electron histories per cm(2)) agree well using standard applicator configurations as well as individually shaped inserts. Profile scans with higher electron energies (>/= 15 MeV) reveal differences up to 5% especially in the penumbra region. Depth dose curves agree best in the vicinity of maximum depths. In the buildup region energy-dependent differences up to 5% in both directions could be observed. In the decay region of depth dose curves calculated doses were up to 10% higher than measured values.


CONCLUSIONS
Good VMC++ accuracy combined with moderate computing times of 1-15 min per beam satisfy all clinical needs. VMC++ allows, for the first time, accurate routine dose evaluations of radiation therapy with electrons. Adequate positioning of the dose reference point is essential. Even small displacements may significantly influence the calculation of monitor units.
Scherf
Christian
C
Klinik und Poliklinik für Strahlentherapie, Klinikum der Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, 60590, Frankfurt/Main, Deutschland. christian.scherf@kgu.de
Scherer
Josef
J
Bogner
Ludwig
L
D000465:Algorithms; D003198:Computer Simulation; D004583:Electrons / Q000627:therapeutic use*; D008954:Models, Biological; D009010:Monte Carlo Method; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012984:Software