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dc.contributor.authorBillas, I
dc.contributor.authorBouchard, H
dc.contributor.authorOelfke, U
dc.contributor.authorDuane, S
dc.date.accessioned2020-06-09T12:02:42Z
dc.date.issued2019-03-14
dc.identifier.citationPhysics in medicine and biology, 2019, 64 (6), pp. 06NT03 - ?
dc.identifier.issn0031-9155
dc.identifier.urihttps://repository.icr.ac.uk/handle/internal/3715
dc.identifier.eissn1361-6560
dc.identifier.doi10.1088/1361-6560/ab0503
dc.description.abstractWith the advent of MRI-guided radiotherapy, the suitability of commercially available radiation dose detectors needs to be assessed. The aim of this study was to investigate the effect of the magnetic field (B-field) on the response of the Gafchromic EBT-3 films. Moreover, as an independent study, we contribute to clarifying the inconsistency of the results of recent published studies, on the effect of B-field on the sensitivity of Gafchromic films. A 60 Co beam was used to irradiate film samples in an electromagnet. An in-house PMMA phantom was designed to fit in the 5 cm gap between the two poles of the magnet. The phantom consists of two symmetrical plates where a film can be inserted. The absorbed dose rate of the 60 Co beam for zero B-field was measured using alanine pellets in a Farmer-type holder. A 12-point response curve was created, representing [Formula: see text] as a function of dose, for each of five different B-field strengths (0 T to 2 T). This study finds that there is at most a small effect of the magnetic field on the response of EBT-3 film. In terms of netOD (red channel) the change in response varied from ‒0.0011 at 0.5 T to 0.0045 at 2.0 T, with a standard uncertainty of 0.0030. If uncorrected, this would lead to an error in film-measured dose, for the red channel, of 2.4% at 2 T, with a standard uncertainty on dose of 1.4%. Results are also presented for B-field strengths of 0.5 T, 1 T and 1.5 T, which are all zero within the measurement uncertainty. Comparison between other studies is also presented. Considering the small change on dose determined with EBT-3 when irradiated under the presence of B-field and taking into account the overall uncertainty in dosimetry using EBT-3 film achieved in this work, EBT-3 is assessed to be a suitable detector for relative and absolute dosimetry, with appropriate corrections, in MRI-guided radiotherapy. The results of the current work also elucidate the inconsistency on the reports from previous studies and demonstrate the necessity of similar investigations by independent teams, especially if the existing results may be in conflict.
dc.formatElectronic
dc.format.extent06NT03 - ?
dc.languageeng
dc.language.isoeng
dc.rights.urihttps://creativecommons.org/licenses/by/4.0
dc.subjectHumans
dc.subjectCobalt Radioisotopes
dc.subjectUncertainty
dc.subjectRadiation Dosage
dc.subjectFilm Dosimetry
dc.subjectPhantoms, Imaging
dc.subjectMagnetic Fields
dc.titleThe effect of magnetic field strength on the response of Gafchromic EBT-3 film.
dc.typeJournal Article
rioxxterms.versionofrecord10.1088/1361-6560/ab0503
rioxxterms.licenseref.urihttps://creativecommons.org/licenses/by/4.0
rioxxterms.licenseref.startdate2019-03-14
rioxxterms.typeJournal Article/Review
dc.relation.isPartOfPhysics in medicine and biology
pubs.issue6
pubs.notesNot known
pubs.organisational-group/ICR
pubs.organisational-group/ICR/Primary Group
pubs.organisational-group/ICR/Primary Group/ICR Divisions
pubs.organisational-group/ICR/Primary Group/ICR Divisions/Radiotherapy and Imaging
pubs.organisational-group/ICR/Primary Group/ICR Divisions/Radiotherapy and Imaging/Radiotherapy Physics Modelling
pubs.organisational-group/ICR
pubs.organisational-group/ICR/Primary Group
pubs.organisational-group/ICR/Primary Group/ICR Divisions
pubs.organisational-group/ICR/Primary Group/ICR Divisions/Radiotherapy and Imaging
pubs.organisational-group/ICR/Primary Group/ICR Divisions/Radiotherapy and Imaging/Radiotherapy Physics Modelling
pubs.publication-statusPublished
pubs.volume64
pubs.embargo.termsNot known
icr.researchteamRadiotherapy Physics Modellingen_US
dc.contributor.icrauthorOelfke, Uween


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