Premium
Normalized glandular dose (DgN) coefficients for arbitrary x‐ray spectra in mammography: Computer‐fit values of Monte Carlo derived data
Author(s) -
Boone John M.
Publication year - 2002
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.1472499
Subject(s) - monte carlo method , mammography , spectral line , physics , computational physics , computation , nuclear medicine , mathematics , medicine , statistics , algorithm , breast cancer , cancer , astronomy
Normalized glandular dose (DgN) values have been reported by several investigators for specific spectra, however for unconventional or unanticipated x‐ray spectra considered for use in mammography, practical methods are not available for DgN computation. In this study, the previously validated SIERRA Monte Carlo code was used to compute the normalized glandular dose coefficients for monoenergetic energies from 8 keV to 50 keV. The overall mammography geometry used was a 65 cm source to image distance, a 1.2 cm air gap between the breast and the detector, and breast thicknesses ranging from 2 to 9 cm. A 4 mm layer of skin was also modeled, and semicircular breast radii of 8.5 cm and 10.0 cm were studied. Breast compositions of 0% glandular, 50% glandular, and 100% glandular were evaluated. The Monte Carlo derived DgN results demonstrated coefficients of variation less than 0.3%. The monoenergetic DgN values, DgN(E), were computer fit using commercial software and the best fit equations are reported. All fits resulted in r 2values of 0.9999 or better. The computer fit equations, along with easy to use spectral modeling routines, are available electronically on the web.