title: Extended collimator model for pencil-beam dose calculation in proton radiotherapy.
abstract: We have developed a simple collimator model to improve the accuracy of penumbra behaviour in pencil-beam dose calculation for proton radiotherapy. In this model, transmission of particles through a three-dimensionally extended opening of a collimator is calculated in conjunction with phase-space distribution of the particles. Comparison of the dose distributions calculated using the new three-dimensional collimator model and the conventional two-dimensional model to lateral dose profiles experimentally measured with collimated proton beams showed the superiority of the new model over the conventional one.
authors.affiliation: National Institute of Radiological Sciences, 4-9-1 Anagawa, Chiba 263-8555, Japan. nkanemat@nirs.go.jp
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kanematsu
authors.forename: Takashi
authors.initials: T
authors.lastname: Akagi
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Takatani
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Yonai
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Sakamoto
authors.forename: Haruo
authors.initials: H
authors.lastname: Yamashita
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D006801:Humans; D015233:Models, Statistical; D016011:Normal Distribution; D011522:Protons; D011878:Radiotherapy / Q000295:instrumentation* / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D011881:Radiotherapy, Computer-Assisted
chemical_list: D011522:Protons