Linked Life Data

19221822

Source:http://linkedlifedata.com/resource/pubmed/id/19221822

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2009-3-11
pubmed:abstractText
An amorphous silicon (a-Si) electronic portal imaging device (EPID) was implemented to perform transit in vivo dosimetry for dynamic conformal arc therapy (DCAT). A set of images was acquired for each arc irradiation using the EPID cine acquisition mode, that supplies a frame acquisition rate of one image every 1.66 s, with a monitor unit rate equal to 100 UM/min. In these conditions good signal stability, +/-1% (2SD) evaluated during 3 months, signal reproducibility within +/-0.8% (2SD) and linearity with dose and dose rate within +/-1% (2SD) were obtained. The transit signal, S (t), due to the transmitted radiotherapy beam below a solid phantom, measured by the EPID cine acquisition mode was used to determine, (1) a set of correlation functions, F(w, L), defined as the ratio between S (t) and the dose at half thickness, D (m), measured in solid water phantoms of different thicknesses, w and with square fields of side L, (2) a set of factors, f(d, L), that take into account the different x-ray scatter contribution from the phantom to the S (t) signal as a function of the variation, d, of the air gap between the phantom and the EPID. The reconstruction of the isocenter dose, D (iso), for DCAT was obtained convolving the transit signal values, obtained at different gantry angles, with the respective reconstruction factors determined by a house-made software. The method was applied to a first patient and the results show that the reconstructed D (iso) values can be obtained with an accuracy within +/-5%. In conclusion, it was assessed that an a-Si EPID with the cine acquisition mode is suitable to perform transit in vivo dosimetry for the DCAT therapy.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1741-0444
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
47
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
425-33
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
In patient dose reconstruction using a cine acquisition for dynamic arc radiation therapy.
pubmed:affiliation
Istituto di Fisica, Università Cattolica del S. Cuore, Largo F. Vito 1, 00168, Rome, Italy. a.piermattei@rm.unicatt.it
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't