Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2001-2-16
pubmed:abstractText
New source designs of encapsulated low-energy gamma emitting nuclides for permanent implants require dosimetric analysis and calibration standardization. The dosimetry measurements can be incorporated into a treatment planning system by fitting the data. The use of a fitting function whose behavior at range limits mimics the physical phenomena, using as few parameters as possible, eliminates noisy outliers and lends credence to calculations beyond the measured range. Clinical implementation of the new sources also requires benchmarking against existing sources, where the current clinical experience lies. We present an analysis of measured dosimetry data for three brachytherapy sources recently available from North American Scientific, Inc. (North Hollywood, CA): 103Pd source model MED3633 ("PdGold"), 125I source models MED3631-A/M ("IoGold-AM") and MED3631-A/S ("IoGold-AS"). Using the formalism of the Interstitial Collaborative Working Group (ICWG) the radial dose function, g(r), the anisotropy function, F(r, theta), and the anisotropy factor, phi an(r), were previously evaluated from measurements of each source design. In this report we use fitting functions whose forms are chosen to approach reasonable values at data limits. These forms are quite similar to those used in a previous analysis of TG43 Iodine and palladium compendium data. Fitting parameter results for each function are provided for each brachytherapy source model. Fit-data discrepancies are smaller than measurement uncertainties, meaning that incorporation into treatment planning systems will not introduce significant errors in clinical use. Current clinical experience is based on the Theragenics (Norcross, GA) 103Pd seed ("PdThera"), and the Nycomed-Amersham (Arlington Heights, IL) 125I seed models 6711 ("6711") and 6702 ("6702"). The new sources are benchmarked against these seeds.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0094-2405
pubmed:author
pubmed:issnType
Print
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2302-6
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Fitting and benchmarking of dosimetry data for new brachytherapy sources.
pubmed:affiliation
Department of Radiation Oncology, St Lukes-Roosevelt Hospital, New York, New York 10019, USA. efurhang@slrhc.org
pubmed:publicationType
Journal Article