Linked Life Data

12817942

Source:http://linkedlifedata.com/resource/pubmed/id/12817942

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2003-6-23
pubmed:abstractText
A simple analytical dose rate calculation model based on primary and scatter separation that treats 192Ir as a monoenergetic source by use of appropriate attenuation and mass energy absorption coefficients is documented for accurate dosimetry in water. This model is then generalized and tested for use in any homogeneous tissue material of radiobiological interest using scatter to primary ratios calculated in water with a material density scaling to account for the difference in the scattering properties of these materials and water. The potential of the analytical model for predicting the effect of the interference of an inhomogeneity is then evaluated by comparison with corresponding Monte Carlo calculations. It is found that regardless of the inhomogeneity dimensions and position relative to the source, the model is capable of increased accuracy (better than 2%) in calculating the primary dose rate at any point not only for low-Z tissue materials but also for high-Z shielding materials where a severe hardening of the primary photons occurs. Overall, for low-Z tissue inhomogeneities the proposed model succeeds in correcting dosimetry results towards the right direction compared to commercial treatment planning systems that currently ignore the effect of phantom dimensions and inhomogeneity interference. Regarding high-Z shielding materials the proposed model accurately predicts the dose reduction just beyond the inhomogeneity (for example it predicts a dose reduction of 47% just behind a tungsten alloy cylinder of 1 cm diameter and 2 mm thickness placed at 1.4 cm away from an 192Ir source, in agreement with corresponding results in the literature) but does not account for the increasing contribution of the laterally scattered photons with increasing distance from the bounded inhomogeneity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0031-9155
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1625-47
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
An analytical dosimetry model as a step towards accounting for inhomogeneities and bounded geometries in 192Ir brachytherapy treatment planning.
pubmed:affiliation
Department of Medical Physics & Engineering, Strahlenklinik, Klinikum Offenbach, 63069 Offenbach, Germany.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't, Evaluation Studies, Validation Studies