Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-4
pubmed:dateCreated
2008-5-22
pubmed:abstractText
The Medical Internal Radiation Dose Committee (MIRD) formalism assumes reference mass values for the organs (source and target) and the total body. MIRD publication 11 provides guidance on how patient-specific scaling of reference radionuclide S-values are to be performed for the electron component of the emission spectrum. However, guidance on patient-specific scaling of the photon contributions to the S-value is given only for those cases where the source and target organs are either far apart or are the same. The photon component of the S-value is derived from photon-Specific Absorbed Fractions (SAFs). These are obtained by Monte Carlo calculation of photon transport. The objective of this work is to verify the MIRD 11 guidance and to examine the relationship between photon SAFs and source/target organ mass when the conditions listed above do not apply. Furthermore, the scaling for photon cross-dose to distributed organs is at present not defined due to lack of data for models other than the reference model. The validity of mass scaling for cross irradiation from near and distant photons sources, especially for Red Bone Marrow (RBM) as a target tissue is also investigated. This is achieved by comparing Monte Carlo-derived SAFs for different source organs to RBM across the GSF voxel phantom series. The results show that, for photon energies greater than 100 keV, the SAF of most source organs to RBM need not be corrected for target mass (error < 5%). In contrast to the results obtained for well-defined source organs, the SAF for RBM irradiating RBM gives a deviation of up to 16% across the different GSF voxel phantoms.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0144-8420
pubmed:author
pubmed:issnType
Print
pubmed:volume
127
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
192-6
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Patient-specific scaling of reference S-values for cross-organ radionuclide S-values: what is appropriate?
pubmed:affiliation
GSF-National Research Center for Environment and Health, Institute of Radiation Protection, Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany. petoussi@gsf.de
pubmed:publicationType
Journal Article