Linked Life Data

15986524

Source:http://linkedlifedata.com/resource/pubmed/id/15986524

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2005-6-29
pubmed:abstractText
Quality assurance (QA) procedures for intensity modulation radiation therapy (IMRT) usually involve an ion chamber measurement in a phantom using the beam configuration of the actual treatment plan. In our QA procedures it was observed that the degree of agreement between the measurement and the calculation could vary from plan to plan, from linac to linac, as well as over time, with a discrepancy up to 8%. In this paper we examine one aspect of the process which can contribute to such poor reproducibility, namely, the leaf end position accuracy. A series of measurements was designed to irradiate an ion chamber using small beam segments where one multileaf collimator (MLC) edge covers half of the chamber. It was shown that the reproducibility varied up to 13%, which provides a possible explanation for the observed discrepancies above. A useful tool was also developed to measure ionization signals from individual segments of an IMRT sequence. In addition, an understanding of the leaf end position variations offers some insight into the overall quality of an IMRT dose distribution.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0094-2405
pubmed:author
pubmed:issnType
Print
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1440-5
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Impact of multileaf collimator leaf positioning accuracy on intensity modulation radiation therapy quality assurance ion chamber measurements.
pubmed:affiliation
Department of Medical Physics, Sunnybrook and Womens Health Sciences Center, Toronto and Department of Medical Biophysics and Department of Radiation Oncology, University of Toronto, Ontario M4N 3M5, Canada. milton.woo@sw.ca
pubmed:publicationType
Journal Article, Evaluation Studies, Validation Studies