title: Design of ridge filters for spread-out Bragg peaks with Monte Carlo simulation in carbon ion therapy.
abstract: Spread-out Bragg peaks made by ridge filters or wheel range modulators are used in charged particle therapy with passive methods to achieve uniform biological responses in irradiated tumors. Following the biological responses needed to design the ridge filters, which were developed at the National Institute of Radiological Sciences in Japan, new ridge filters were designed using recent developments in heavy-ion reactions and dosimetry. The Monte Carlo code of Geant4 was used to calculate the qualities of carbon ion beams in a water phantom. The results obtained from the simulation were corrected so that they agreed with the measurements of depth dose distributions. The calculations of biological responses to fragments other than carbon ions were assumed to be for helium ions. The measured dose distributions with the designed ridge filters were compared to the calculated distributions. A beam modifying system using this adaptable method was successively applied to carbon ion therapy at Gunma University.
authors.affiliation: Department of Electrical and Electronic Engineering, College of Industrial Technology, Nihon University, 1-2-1, Izumicho, Narashino, Chiba 275-8575 Japan. sakama.makoto@nihon-u.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Sakama
authors.forename: T
authors.initials: T
authors.lastname: Kanai
authors.forename: Y
authors.initials: Y
authors.lastname: Kase
authors.forename: K
authors.initials: K
authors.lastname: Yusa
authors.forename: M
authors.initials: M
authors.lastname: Tashiro
authors.forename: K
authors.initials: K
authors.lastname: Torikai
authors.forename: H
authors.initials: H
authors.lastname: Shimada
authors.forename: S
authors.initials: S
authors.lastname: Yamada
authors.forename: T
authors.initials: T
authors.lastname: Ohno
authors.forename: T
authors.initials: T
authors.lastname: Nakano
mesh_terms: D063193:Heavy Ion Radiotherapy / Q000379:methods*; D009010:Monte Carlo Method; D011874:Radiometry; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*