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dc.contributor.authorThomas, MDR
dc.contributor.authorSymonds-Tayler, JRN
dc.date.accessioned2018-07-27T14:56:25Z
dc.date.issued2003-08-21
dc.identifier16
dc.identifier.citationPHYSICS IN MEDICINE AND BIOLOGY, 2003, 48 pp. 2633 - 2644
dc.identifier.issn0031-9155
dc.identifier.urihttps://repository.icr.ac.uk/handle/internal/2205
dc.identifier.doi10.1088/0031-9155/48/16/305
dc.description.abstractA system for radiotherapy treatment verification is proposed, using an air-ionization chamber with 1600 simultaneously readable 1 cm pixels. An image of the entire beam may be used to calibrate a portal image, to verify the position of the multi-leaf collimator with respect to delivered dose (either before or during treatment) and to check beam flatness and symmetry. This study characterizes the physical behaviour of such a system. A test chamber has been constructed and its temporal and spatial resolution and noise characteristics are evaluated. Several parameters of the design are varied, and their effects assessed. Temporal resolution is adequate to allow readout between each linear accelerator pulse at 400 pulses per second. Application of low atomic-number build-up and reduction of plate separation were the most effective methods to improve spatial resolution. The full width at half maximum of the line-spread function is shown to be 4.5 mm using a pre-sampling technique. The peak pixel-signal to x-ray quantum noise ratio exceeds 100. Prototype electronics have been tested, demonstrating that electronic noise could be reduced to a level below the x-ray quantum noise. The results of the study allow the simulation of any possible application to evaluate the proposed verification system.
dc.format.extent2633 - 2644
dc.languageeng
dc.language.isoeng
dc.publisherIOP PUBLISHING LTD
dc.titleCharacterization of a transmission ionization beam-imager for radiotherapy verification
dc.typeJournal Article
rioxxterms.versionofrecord10.1088/0031-9155/48/16/305
rioxxterms.licenseref.startdate2003-08-21
rioxxterms.typeJournal Article/Review
dc.relation.isPartOfPHYSICS IN MEDICINE AND BIOLOGY
pubs.notesaffiliation: Thomas, MDR (Reprint Author), Middlesex Hosp, Mortimer St, London WIT 3AA, England. Kings Coll Hosp, London SE5 9RS, England. Inst Canc Res, Joint Dept Phys, Sutton SM2 8PT, Surrey, England. article-number: PII S0031-9155(03)56531-9 keywords-plus: IMAGING-SYSTEM; DEVICE research-areas: Engineering; Radiology, Nuclear Medicine & Medical Imaging web-of-science-categories: Engineering, Biomedical; Radiology, Nuclear Medicine & Medical Imaging number-of-cited-references: 13 times-cited: 0 usage-count-last-180-days: 0 usage-count-since-2013: 0 journal-iso: Phys. Med. Biol. doc-delivery-number: 724VK unique-id: ISI:000185507200005 da: 2018-07-27
pubs.notesNot known
pubs.organisational-group/ICR
pubs.organisational-group/ICR
pubs.volume48
pubs.embargo.termsNot known
dc.contributor.icrauthorThomas, Michaelen


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