Technical Note: Experimental characterization of the dose deposition in parallel MRI-linacs at various magnetic field strengths.

Magnetic Fields Magnetic Resonance Imaging / instrumentation Particle Accelerators
MRI-Linac dose deposition magnetic field parallel orientation

Journal

Medical physics
ISSN: 2473-4209
Titre abrégé: Med Phys
Pays: United States
ID NLM: 0425746

Informations de publication

Date de publication:
Nov 2019
Historique:
received: 29 01 2019
revised: 05 08 2019
accepted: 06 08 2019
pubmed: 17 8 2019
medline: 19 3 2020
entrez: 17 8 2019
Statut: ppublish

Résumé

Dose deposition measurements for parallel MRI-linacs have previously only shown comparisons between 0 T and a single available magnetic field. The Australian MRI-Linac consists of a magnet coupled with a dual energy linear accelerator and a 120 leaf Multi-Leaf Collimator with the radiation beam parallel to the magnetic field. Two different magnets, with field strengths of 1 and 1.5 T, were used during prototyping. This work aims to characterize the impact of the magnetic field at 1 and 1.5 T on dose deposition, possible by comparing dosimetry measured at both magnetic field strengths to measurements without the magnetic field. Dose deposition measurements focused on a comparison of beam quality (TPR Beam quality was within ±0.5% of the 0 T value for the 1 and 1.5 T magnetic field strengths. PDDs and profiles showed agreement for the three magnetic field strengths at depths beyond 20 mm. Deposited dose increased at shallower depths due to electron focusing. Output factors showed agreement within 1%. Dose deposition at depth for a parallel MRI-linac was not significantly impacted by either a 1 or 1.5 T magnetic field. PDDs and profiles at shallow depths and surface dose measurements showed significant differences between 0, 1, and 1.5 T due to electron focusing.

Identifiants

DOI: 10.1002/mp.13767 PMID: 31419317
pubmed: 31419317
doi: 10.1002/mp.13767
doi:

Types de publication

Journal Article

Langues

eng

Sous-ensembles de citation

IM

Pagination

5152-5158

Subventions

Organisme : NHMRC Program
ID : 1036078

Informations de copyright

© 2019 American Association of Physicists in Medicine.

Références

Lagendijk JJW, Raaymakers BW, van Vulpen M. The magnetic resonance imaging-linac system. Semin Radiat Oncol. 2014;24:207-209.
Mutic S, Dempsey JF. The ViewRay System: magnetic resonance-guided and controlled radiotherapy. Semin Radiat Oncol. 2014;24:196-199.
Fallone BG. The rotating biplanar linac-magnetic resonance imaging system. Semin Radiat Oncol. 2014;24:200-202.
Fallone B, Murray B, Rathee S, et al. First MR images obtained during megavoltage photon irradiation from a prototype integrated linac-MR system. Med Phys. 2009;36:2084-2088.
Raaymakers B, Lagendijk J, Overweg J, et al. Integrating a 1.5 T MRI scanner with a 6 MV accelerator: proof of concept. Phys Med Biol. 2009;54:N229-N237.
Keall PJ, Barton M, Crozier S. The Australian Magnetic Resonance Imaging-Linac Program. Semin Radiat Oncol. 2014;24:203-206.
Liney GP, Dong B, Begg J, et al. Experimental results from a prototype high-field inline MRI-linac. Med Phys. 2016;43:5188-5194.
St Aubin J, Santos D, Steciw S, Fallone B. Effect of longitudinal magnetic fields on a simulated in-line 6 MV linac. Med Phys. 2010;37:4916-4923.
Brendan W, Lois H, Dragos C, et al. Performance of a clinical gridded electron gun in magnetic fields: Implications for MRI-linac therapy. Med Phys. 2016;43:5903-5914.
Constantin DE, Fahrig R, Keall PJ. A study of the effect of in-line and perpendicular magnetic fields on beam characteristics of electron guns in medical linear accelerators. Med Phys. 2011;38:4174-4185.
Moylan R, Aland T, Kairn T. Dosimetric accuracy of Gafchromic EBT2 and EBT3 film for in vivo dosimetry. Australas Phys Eng Sci Med. 2013;36:331-337.
Sorriaux J, Kacperek A, Rossomme S, et al. Evaluation of Gafchromic® EBT3 films characteristics in therapy photon, electron and proton beams. Physica Med. 2013;29:599-606.
Borca VC, Pasquino M, Russo G, et al. Dosimetric characterization and use of GAFCHROMIC EBT3 film for IMRT dose verification. J Appl Clin Med Phys. 2013;14:158-171.
Klein EE, Hanley J, Bayouth J, et al. Task Group 142 report: quality assurance of medical accelerators. Med Phys. 2009;36:4197-4212.
O'Brien DJ, Roberts DA, Ibbott GS, Sawakuchi GO. Reference dosimetry in magnetic fields: formalism and ionization chamber correction factors. Med Phys. 2016;43:4915-4927.
Oborn BM, Ge Y, Hardcastle N, Metcalfe PE, Keall PJ. Dose enhancement in radiotherapy of small lung tumors using inline magnetic fields: A Monte Carlo based planning study. Med Phys. 2016;43:368-377.
Bielajew AF. The effect of strong longitudinal magnetic fields on dose deposition from electron and photon beams. Med Phys. 1993;20:1171-1179.
Oborn B, Metcalfe PE, Butson M, Rosenfeld AB, Keall P. Electron contamination modeling and skin dose in 6 MV longitudinal field MRIgRT: Impact of the MRI and MRI fringe field. Med Phys. 2012;39:874-890.
Keyvanloo A, Burke B, Warkentin B, et al. Skin dose in longitudinal and transverse linac-MRIs using Monte Carlo and realistic 3D MRI field models. Med Phys. 2012;39:6509-6521.
Butson MJ, Yu PK, Metcalfe PE. Extrapolated surface dose measurements with radiochromic film. Med Phys. 1999;26:485-488.
Aspradakis M, Byrne J, Palmans H, et al. Report 103: small field. MV photon dosimetry. 2010.
Hackett SL, Van Asselen B, Wolthaus J, et al. Consequences of air around an ionization chamber: are existing solid phantoms suitable for reference dosimetry on an MR-linac? Med Phys. 2016;43:3961-3968.
Agnew J, O'Grady F, Young R, Duane S, Budgell GJ. Quantification of static magnetic field effects on radiotherapy ionization chambers. Phys Med Biol. 2017;62:1731.
O'Brien DJ, Sawakuchi GO. Monte Carlo study of the chamber-phantom air gap effect in a magnetic field. Med Phys. 2017;44:3830-3838.
Malkov V, Rogers D. Charged particle transport in magnetic fields in EGSnrc. Med Phys. 2016;43:4447-4458.
Barten DL, Hoffmans D, Palacios MA, Heukelom S, van Battum LJ. Suitability of EBT3 GafChromic film for quality assurance in MR-guided radiotherapy at 0.35 T with and without real-time MR imaging. Phys Med Biol. 2018;63:165014.
Delfs B, Schoenfeld AA, Poppinga D, et al. Magnetic fields are causing small, but significant changes of the radiochromic EBT3 film response to 6 MV photons. Phys Med Biol. 2018;63:035028.
Begg J, George A, Alnaghy S, et al. The Australian MRI-Linac Program: measuring profiles and PDD in a horizontal beam. J Phys: Conf Ser. 2017;777:012035.

Auteurs

Jarrad Begg (J)

Department of Medical Physics, Liverpool and Macarthur Cancer Therapy Centre, Liverpool, NSW, 2170, Australia.
Ingham Institute for Applied Medical Research, Liverpool, NSW, 2170, Australia.
South Western Sydney Clinical School, University of New South Wales, Liverpool, NSW, 2170, Australia.

Sarah J Alnaghy (SJ)

Ingham Institute for Applied Medical Research, Liverpool, NSW, 2170, Australia.
Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, 2522, Australia.

Trent Causer (T)

Ingham Institute for Applied Medical Research, Liverpool, NSW, 2170, Australia.
Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, 2522, Australia.

Thahabah Alharthi (T)

Ingham Institute for Applied Medical Research, Liverpool, NSW, 2170, Australia.
Sydney Medical School, University of Sydney, Camperdown, NSW, 2505, Australia.

Armia George (A)

Department of Medical Physics, Liverpool and Macarthur Cancer Therapy Centre, Liverpool, NSW, 2170, Australia.
Ingham Institute for Applied Medical Research, Liverpool, NSW, 2170, Australia.

Laura Glaubes (L)

Sydney Medical School, University of Sydney, Camperdown, NSW, 2505, Australia.

Bin Dong (B)

Ingham Institute for Applied Medical Research, Liverpool, NSW, 2170, Australia.
Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, 2522, Australia.

Gary Goozee (G)

Department of Medical Physics, Liverpool and Macarthur Cancer Therapy Centre, Liverpool, NSW, 2170, Australia.
Ingham Institute for Applied Medical Research, Liverpool, NSW, 2170, Australia.

Paul Keall (P)

Ingham Institute for Applied Medical Research, Liverpool, NSW, 2170, Australia.
ACRF Image X Institute , Sydney Medical School, University of Sydney, Liverpool, NSW, 2170, Australia.

Urszula Jelen (U)

Ingham Institute for Applied Medical Research, Liverpool, NSW, 2170, Australia.

Gary Liney (G)

Department of Medical Physics, Liverpool and Macarthur Cancer Therapy Centre, Liverpool, NSW, 2170, Australia.
Ingham Institute for Applied Medical Research, Liverpool, NSW, 2170, Australia.
Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, 2522, Australia.
Sydney Medical School, University of Sydney, Camperdown, NSW, 2505, Australia.

Lois Holloway (L)

Department of Medical Physics, Liverpool and Macarthur Cancer Therapy Centre, Liverpool, NSW, 2170, Australia.
Ingham Institute for Applied Medical Research, Liverpool, NSW, 2170, Australia.
South Western Sydney Clinical School, University of New South Wales, Liverpool, NSW, 2170, Australia.
Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, 2522, Australia.
Institute of Medical Physics, University of Sydney, Camperdown, NSW, 2505, Australia.
Sydney Medical School, University of Sydney, Camperdown, NSW, 2505, Australia.

Articles similaires

Pulmonary Atelectasis After Sedation With Propofol vs Propofol-Ketamine for Magnetic Resonance Imaging in Children: A Randomized Clinical Trial.

Yu Jeong Bang, Jeayoun Kim, Nam-Su Gil et al.
1.00
Humans Ketamine Propofol Pulmonary Atelectasis Female

Customization of neonatal functional magnetic resonance imaging: A preclinical phantom-based study.

Juan F Quinones, Tina Schmitt, Tommaso Pavan et al.
1.00
Humans Magnetic Resonance Imaging Phantoms, Imaging Infant, Newborn Signal-To-Noise Ratio

Multilabel SegSRGAN-A framework for parcellation and morphometry of preterm brain in MRI.

Guillaume Dollé, Gauthier Loron, Margaux Alloux et al.
1.00
Humans Magnetic Resonance Imaging Brain Infant, Newborn Infant, Premature

Defining multilevel developmental cervical spinal stenosis using MRI.

Prudence W H Cheung, Justin H M Leung, Vivien W Y Lee et al.
1.00
Humans Male Female Magnetic Resonance Imaging Middle Aged

Classifications MeSH

questionsmedicales.fr › Phénomènes physiques › Phénomènes magnétiques › Champs magnétiques › Technical Note: Experimental characterization...
questionsmedicales.fr › Diagnostic › Techniques et procédures diagnostiques › Imagerie diagnostique › Tomographie › Imagerie par résonance magnétique › Technical Note: Experimental characterization...
questionsmedicales.fr › Équipement et fournitures › Équipement et fournitures pour les applications des radiations › Accélérateurs de particules › Technical Note: Experimental characterization...