Ionization chamber correction factors for MR-linacs

Physics in Medicine and Biology
Stefan PojtingerDaniela Thorwarth

Abstract

Previously, readings of air-filled ionization chambers have been described as being influenced by magnetic fields. To use these chambers for dosimetry in magnetic resonance guided radiotherapy (MRgRT), this effect must be taken into account by introducing a correction factor k B. The purpose of this study is to systematically investigate k B for a typical reference setup for commercially available ionization chambers with different magnetic field strengths. The Monte Carlo simulation tool EGSnrc was used to simulate eight commercially available ionization chambers in magnetic fields whose magnetic flux density was in the range of 0-2.5 T. To validate the simulation, the influence of the magnetic field was experimentally determined for a PTW30013 Farmer-type chamber for magnetic flux densities between 0 and 1.425 T. Changes in the detector response of up to 8% depending on the magnetic flux density, on the chamber geometry and on the chamber orientation were obtained. In the experimental setup, a maximum deviation of less than 2% was observed when comparing measured values with simulated values. Dedicated values for two MR-linac systems (ViewRay MRIdian, ViewRay Inc, Cleveland, United States, 0.35 T/ 6 MV and Elekta Unity, Elekt...Continue Reading

References

Jun 23, 2006·Physics in Medicine and Biology·D W O Rogers
Jul 11, 2006·Physics in Medicine and Biology·J Sempau, P Andreo
May 20, 2009·Physics in Medicine and Biology·B W RaaymakersK J Brown
Jun 17, 2014·Seminars in Radiation Oncology·Biagio Gino Fallone
Jun 17, 2014·Seminars in Radiation Oncology·Paul J KeallUNKNOWN Australian MRI-Linac Program, including contributors from Ingham Institute, Illawarra Cancer Care Centre, Liverpool Hospital
Nov 19, 2015·Physics in Medicine and Biology·J A de PooterH Bouchard
Mar 24, 2016·Physics in Medicine and Biology·Falk TillnerWolfgang Enghardt
May 11, 2016·Radiotherapy and Oncology : Journal of the European Society for Therapeutic Radiology and Oncology·A J McPartlinUNKNOWN MR-Linac consortium
Jul 3, 2016·Medical Physics·V N Malkov, D W O Rogers
Dec 13, 2016·Radiotherapy and Oncology : Journal of the European Society for Therapeutic Radiology and Oncology·Benjamin SandersonAnanya Choudhury
Jun 22, 2017·Medical Physics·Victor N Malkov, D W O Rogers

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Citations

Apr 2, 2019·Physics in Medicine and Biology·Leon de PrezBas Raaymakers
Jul 16, 2019·Physics in Medicine and Biology·Levi MaddenAnatoly Rosenfeld
Nov 14, 2019·Journal of Applied Clinical Medical Physics·Stephen A GravesDaniel E Hyer
Jan 10, 2020·Medical Physics·Sarah J AlnaghyPeter Metcalfe
Mar 20, 2020·Physics in Medicine and Biology·Ilias BillasSimon Duane
Nov 27, 2018·Physics in Medicine and Biology·E Simiele, L DeWerd
Aug 1, 2020·Physics in Medicine and Biology·Achim KraussSebastian Klüter
Jun 23, 2020·Physics in Medicine and Biology·Jacco de PooterJochem Wolthaus
Mar 26, 2021·Frontiers in Oncology·Daniela Thorwarth, Daniel A Low
Dec 17, 2020·Medical Physics·Hermann FuchsDietmar Georg

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