title: Design and application of 3D-printed stepless beam modulators in proton therapy.
abstract: A new method for the design of stepless beam modulators for proton therapy is described and verified. Simulations of the classic designs are compared against the stepless method for various modulation widths which are clinically applicable in proton eye therapy. Three modulator wheels were printed using a Stratasys Objet30 3D printer. The resulting depth dose distributions showed improved uniformity over the classic stepped designs. Simulated results imply a possible improvement in distal penumbra width; however, more accurate measurements are needed to fully verify this effect. Lastly, simulations were done to model bio-equivalence to Co-60 cell kill. A wheel was successfully designed to flatten this metric.
authors.affiliation: Department of Physics and Astronomy, University of Victoria, Victoria BC V8W 3P6, Canada. Department of Life Science, TRIUMF, Vancouver BC V6T 2A3, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Lindsay
authors.forename: J
authors.initials: J
authors.lastname: Kumlin
authors.forename: D M
authors.initials: DM
authors.lastname: Martinez
authors.forename: A
authors.initials: A
authors.lastname: Jirasek
authors.forename: C
authors.initials: C
authors.lastname: Hoehr
mesh_terms: D003037:Cobalt Radioisotopes / Q000627:therapeutic use; D004867:Equipment Design; D008954:Models, Biological; D066330:Printing, Three-Dimensional; D061766:Proton Therapy / Q000295:instrumentation / Q000379:methods*; D011879:Radiotherapy Dosage
chemical_list: D003037:Cobalt Radioisotopes