title: Dosimetric feasibility of intensity modulated proton therapy in a transverse magnetic field of 1.5 T.
abstract: Proton therapy promises higher dose conformality in comparison with regular radiotherapy techniques. Also, image guidance has an increasing role in radiotherapy and MRI is a prime candidate for this imaging. Therefore, in this paper the dosimetric feasibility of Intensity Modulated Proton Therapy (IMPT) in a magnetic field of 1.5 T and the effect on the generated dose distributions compared to those at 0 T is evaluated, using the Monte Carlo software TOol for PArticle Simulation (TOPAS). For three different anatomic sites IMPT plans are generated. It is shown that the generation of an IMPT plan in a magnetic field is feasible, the impact of the magnetic field is small, and the resulting dose distributions are equivalent for 0 T and 1.5 T. Also, the framework of Monte Carlo simulation combined with an inverse optimization method can be used to generate IMPT plans. These plans can be used in future dosimetric comparisons with e.g. IMRT and conventional IMPT. Finally, this study shows that IMPT in a 1.5 T magnetic field is dosimetrically feasible.
authors.affiliation: Department of Radiotherapy, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Hartman
authors.forename: Charis
authors.initials: C
authors.lastname: Kontaxis
authors.forename: G H
authors.initials: GH
authors.lastname: Bol
authors.forename: S J
authors.initials: SJ
authors.lastname: Frank
authors.forename: J J W
authors.initials: JJ
authors.lastname: Lagendijk
authors.forename: M
authors.initials: M
authors.lastname: van Vulpen
authors.forename: B W
authors.initials: BW
authors.lastname: Raaymakers
mesh_terms: D006801:Humans; D008279:Magnetic Resonance Imaging; D061766:Proton Therapy / Q000379:methods*; D011874:Radiometry / Q000379:methods; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*