title: Performance of a cylindrical diode array for use in a 1.5 T MR-linac.
abstract: At the UMC Utrecht, a linear accelerator with integrated magnetic resonance imaging (MRI) has been developed, the MR-linac. Patient-specific quality assurance (QA) of treatment plans for MRI-based image guided radiotherapy requires QA equipment compatible with this 1.5 T magnetic field. The purpose of this study was to examine the performance characteristics of the ArcCHECK-MR in a transverse 1.5 T magnetic field. To this end, the short-term reproducibility, dose linearity, dose rate dependence, field size dependence, dose per pulse dependence and inter-diode dose response variation of the ArcCHECK-MR diode array were evaluated on a conventional linac and on the MR-linac. The ArcCHECK-MR diode array performed well for all tests on both linacs, no significant differences in performance characteristics were observed. Differences in the maximum dose deviations between both linacs were less than 1.5%. Therefore, we conclude that the ArcCHECK-MR can be used in a transverse 1.5 T magnetic field.
authors.affiliation: Department of Radiation Oncology, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: A C
authors.initials: AC
authors.lastname: Houweling
authors.forename: J H W
authors.initials: JH
authors.lastname: de Vries
authors.forename: J
authors.initials: J
authors.lastname: Wolthaus
authors.forename: S
authors.initials: S
authors.lastname: Woodings
authors.forename: J G M
authors.initials: JG
authors.lastname: Kok
authors.forename: B
authors.initials: B
authors.lastname: van Asselen
authors.forename: K
authors.initials: K
authors.lastname: Smit
authors.forename: A
authors.initials: A
authors.lastname: Bel
authors.forename: J J W
authors.initials: JJ
authors.lastname: Lagendijk
authors.forename: B W
authors.initials: BW
authors.lastname: Raaymakers
mesh_terms: D060526:Magnetic Fields; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010315:Particle Accelerators / Q000295:instrumentation* / Q000592:standards; D011874:Radiometry / Q000379:methods; D015203:Reproducibility of Results