title: Monte Carlo simulation of a medical linear accelerator for radiotherapy use.
abstract: A Monte Carlo code MCNPX (Monte Carlo N-particle) was used to model a 25 MV photon beam from a PRIMUS (KD2-Siemens) medical linear electron accelerator at the Centre Antoine Lacassagne in Nice. The entire geometry including the accelerator head and the water phantom was simulated to calculate the dose profile and the relative depth-dose distribution. The measurements were done using an ionisation chamber in water for different square field ranges. The first results show that the mean electron beam energy is not 19 MeV as mentioned by Siemens. The adjustment between the Monte Carlo calculated and measured data is obtained when the mean electron beam energy is approximately 15 MeV. These encouraging results will permit to check calculation data given by the treatment planning system, especially for small fields in high gradient heterogeneous zones, typical for intensity modulated radiation therapy technique.
authors.affiliation: LPES-CRESA, Laboratoire de Physique Electronique des Solides, Centre de Recherche sur les Solides et leurs Applications, EA1174, Université de Nice-Sophia Antipolis, Parc Valrose, 06108 Nice cedex 2, France. bserrano@unice.fr
authors.forename: B
authors.initials: B
authors.lastname: Serrano
authors.forename: A
authors.initials: A
authors.lastname: Hachem
authors.forename: E
authors.initials: E
authors.lastname: Franchisseur
authors.forename: J
authors.initials: J
authors.lastname: Hérault
authors.forename: S
authors.initials: S
authors.lastname: Marcié
authors.forename: A
authors.initials: A
authors.lastname: Costa
authors.forename: R J
authors.initials: RJ
authors.lastname: Bensadoun
authors.forename: J
authors.initials: J
authors.lastname: Barthe
authors.forename: J P
authors.initials: JP
authors.lastname: Gérard
mesh_terms: D001822:Body Burden; D004583:Electrons / Q000627:therapeutic use; D006801:Humans; D008954:Models, Biological; D015233:Models, Statistical; D009010:Monte Carlo Method; D010315:Particle Accelerators / Q000295:instrumentation*; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D020266:Radiotherapy, Conformal / Q000295:instrumentation* / Q000379:methods*; D012062:Relative Biological Effectiveness