title: Monte Carlo modeling of the Siemens Optifocus multileaf collimator.
abstract: We have developed a new component module for the BEAMnrc software package, called SMLC, which models the tongue-and-groove structure of the Siemens Optifocus multileaf collimator. The ultimate goal is to perform accurate Monte Carlo simulations of the IMRT treatments carried out with Optifocus. SMLC has been validated by direct geometry checks and by comparing quantitatively the results of simulations performed with it and with the component module VARMLC. Measurements and Monte Carlo simulations of absorbed dose distributions of radiation fields sensitive to the tongue-and-groove effect have been performed to tune the free parameters of SMLC. The measurements cannot be accurately reproduced with VARMLC. Finally, simulations of a typical IMRT field showed that SMLC improves the agreement with experimental measurements with respect to VARMLC in clinically relevant cases.
  87.55. K.
authors: Servicio de Física y Protección Radiológica, Hospital Universitario Lozano Blesa, Av. San Juan Bosco 15, 50009 Zaragoza, Spain. Electronic address: lalienavm@gmail.com.
authors: Victor
authors: V
authors: Laliena
authors: Servicio de Física y Protección Radiológica, Hospital Universitario Lozano Blesa, Av. San Juan Bosco 15, 50009 Zaragoza, Spain.
authors: Alejandro
authors: A
authors: García-Romero
mesh_terms: D006801:Humans; D009010:Monte Carlo Method; D010315:Particle Accelerators; D011874:Radiometry; D050397:Radiotherapy, Intensity-Modulated / Q000295:instrumentation*; D015203:Reproducibility of Results; D012984:Software
keywords: BEAMnrc; IMRT; Monte Carlo; Multileaf collimator; Tongue-and-groove