Linked Life Data

16723772

Source:http://linkedlifedata.com/resource/pubmed/id/16723772

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2006-5-25
pubmed:abstractText
There is a growing interest in Gafchromic films for patient dosimetry in radiotherapy and in radiology. A new model (XR-QA) with high sensitivity to low dose was tested in this study. The response of the film to different x-ray beam energies (range 28-145 kVp with various filtrations, dose range 0-100 mGy) and to visible light was investigated, together with the after exposure darkening properties. Exposed films were digitized with a commercially available, optical flatbed scanner. A single functional form for dose versus net pixel value variation has been determined for all the obtained calibration curves, with a unique fit parameter different for each of the used x-ray beams. The film response was dependent on beam energy, with higher colour variations for the beams in the range 80-140 kVp. Different sources of uncertainties in dose measurements, governed by the digitalization process, the film response uniformity and the calibration curve fit procedure, have been considered. The overall one-sigma dose measurement uncertainty depended on the beam energy and decreased with increasing absorbed dose. For doses above 10 mGy and beam energies in the range 80-140 kVp the total uncertainty was less than 5%, whereas for the 28 kVp beam the total uncertainty at 10 mGy was about 10%. The post-exposure colour variation was not negligible in the first 24 h after the exposure, with a consequent increase in the calculated dose of about 10%. Results of the analysis of the sensitivity to visible light indicated that a short exposure of this film to ambient and scanner light during the measurements will not have a significant impact on the radiation dosimetry.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0031-9155
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
51
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2871-81
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Dose and energy dependence of response of Gafchromic XR-QA film for kilovoltage x-ray beams.
pubmed:affiliation
Struttura Complessa Fisica Sanitaria, Azienda Ospedaliera San Giovanni Battista, Corso Bramante 88, 10126 Torino, Italy. orampado@molinette.piemonte.it
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't