Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
2003-10-7
pubmed:abstractText
This report contains the recommendations of the Electron Dosimetry Working Party of the UK Institute of Physics and Engineering in Medicine (IPEM). The recommendations consist of a code of practice for electron dosimetry for radiotherapy beams of initial energy from 4 to 25 MeV. The code is based on the absorbed dose to water calibration service for electron beams provided by the UK standards laboratory, the National Physical Laboratory (NPL). This supplies direct N(D,w) calibration factors, traceable to a calorimetric primary standard, at specified reference depths over a range of electron energies up to approximately 20 MeV. Electron beam quality is specified in terms of R(50,D), the depth in water along the beam central axis at which the dose is 50% of the maximum. The reference depth for any given beam at the NPL for chamber calibration and also for measurements for calibration of clinical beams is 0.6R(50.D) - 0.1 cm in water. Designated chambers are graphite-walled Farmer-type cylindrical chambers and the NACP- and Roos-type parallel-plate chambers. The practical code provides methods to determine the absorbed dose to water under reference conditions and also guidance on methods to transfer this dose to non-reference points and to other irradiation conditions. It also gives procedures and data for extending up to higher energies above the range where direct calibration factors are currently available. The practical procedures are supplemented by comprehensive appendices giving discussion of the background to the formalism and the sources and values of any data required. The electron dosimetry code improves consistency with the similar UK approach to megavoltage photon dosimetry, in use since 1990. It provides reduced uncertainties, approaching 1% standard uncertainty in optimal conditions, and a simpler formalism than previous air kerma calibration based recommendations for electron dosimetry.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0031-9155
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2929-70
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
The IPEM code of practice for electron dosimetry for radiotherapy beams of initial energy from 4 to 25 MeV based on an absorbed dose to water calibration.
pubmed:affiliation
Institute of Physics and Engineering in Medicine, Fairmount House, 230 Tadcaster Road, York YO24 1ES, UK.
pubmed:publicationType
Journal Article, Guideline