title: Design of beam-modulating devices for charged-particle therapy.
abstract: The computer modeling program used to design beam-modulating devices for charged-particle therapy at Lawrence Berkeley Laboratory has been improved to allow a more realistic description of the beam. The original program used a single calculated Bragg peak to design the spread Bragg peak. The range of this curve was shifted so that Bragg curves of varying ranges could be superimposed. The new version of the program allows several measured Bragg curves with different ranges to be used as input, and interpolates between them to obtain the required data for the superposition calculation. The experimental configuration for measuring these input curves simulated therapy conditions. Seven beam-modulating propellers with spread Bragg-peak widths ranging from 2.2 to 14.4 cm were designed and constructed for a 215-MeV/u helium beam using this new design program. Depth-dose distributions produced by these new propellers were in good agreement with predicted distributions, and these propellers are currently being used clinically.
authors.affiliation: Research Medicine and Radiation Biophysics Division, University of California, Lawrence Berkeley Laboratory, Berkeley 94720.
authors.forename: P L
authors.initials: PL
authors.lastname: Petti
authors.forename: J T
authors.initials: JT
authors.lastname: Lyman
authors.forename: T R
authors.initials: TR
authors.lastname: Renner
authors.forename: J R
authors.initials: JR
authors.lastname: Castro
authors.forename: J M
authors.initials: JM
authors.lastname: Collier
authors.forename: I K
authors.initials: IK
authors.lastname: Daftari
authors.forename: B A
authors.initials: BA
authors.lastname: Ludewigt
mesh_terms: D004867:Equipment Design; D006371:Helium; D007477:Ions; D010315:Particle Accelerators / Q000295:instrumentation*; D011882:Radiotherapy, High-Energy / Q000295:instrumentation*; D012984:Software
chemical_list: D007477:Ions; D006371:Helium