title: Secondary range shifting with range compensator for reduction of beam data library in heavy-ion radiotherapy.
abstract: We report our experience with extended usage of range compensators in heavy-ion radiotherapy with broad beams to lighten the management task of the beam data library, which is a collection of the standard beams to be referenced in treatment planning. Partly due to interference between lateral spreading and range shifting, as many as hundreds of beam entries may be necessary to cover all the possible clinical situations. We have introduced downstream secondary range shifting with a range compensator to reduce the interference and consequently to simplify the library. In our case, 30% reduction in beam entries is achieved without significantly degrading the beam quality nor increasing the material consumption by more than 3%, which is experimentally verified with carbon-ion beams or statistically estimated from the clinical records.
authors.affiliation: National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan. nkanemat@go.jp
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kanematsu
authors.forename: Masami
authors.initials: M
authors.lastname: Torikoshi
authors.forename: Manabu
authors.initials: M
authors.lastname: Mizota
authors.forename: Tatsuaki
authors.initials: T
authors.lastname: Kanai
mesh_terms: D016208:Databases, Factual; D004867:Equipment Design; D019544:Equipment Failure Analysis; D063193:Heavy Ion Radiotherapy; D016247:Information Storage and Retrieval / Q000379:methods*; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D011882:Radiotherapy, High-Energy / Q000295:instrumentation* / Q000379:methods