摘要
The average absorbed dose in glandular tissue is the most appropriate parameter for the assessment of the radiation-induced risk during breast imaging. The aims of this work concern:(1) the investigation of the variation effect of any related update to photon cross-section data-bases on the computation of the normalized glandular dose(Dg N) for mammography quality control tests and(2) the proposition of a parameterization method leading to provide Dg N values function of the breast thickness(T) and the particle energy(E) instead of E alone, as normally known. We analyzed the change effect of the photon cross-section data-bases on the computation of Dg N. Those coefficients, generated using the Geant4 Monte Carlo toolkit, were studied over a range of compressed breast thickness of 2–8 cm for monoenergetic(1–120 ke V by 1 ke V intervals) and polyenergetic(23–35 k Vp by 2 k Vp intervals) X-ray beams. Moreover, breast tissue composition ranging from about0% glandular(about 100% adipose) to 100% glandular(0% adipose) was also covered. The successful parameterization of Dg N look-up table function of the breast thickness and energy, will compact its analytical form without loss of accuracy. All parameterization fits resulted in r2 values of 0.999 or better.
The average absorbed dose in glandular tissue is the most appropriate parameter for the assessment of the radiation-induced risk during breast imaging. The aims of this work concern：（1） the investigation of the variation effect of any related update to photon cross-section data-bases on the computation of the normalized glandular dose（Dg N） for mammography quality control tests and（2） the proposition of a parameterization method leading to provide Dg N values function of the breast thickness（T） and the particle energy（E） instead of E alone, as normally known. We analyzed the change effect of the photon cross-section data-bases on the computation of Dg N. Those coefficients, generated using the Geant4 Monte Carlo toolkit, were studied over a range of compressed breast thickness of 2–8 cm for monoenergetic（1–120 ke V by 1 ke V intervals） and polyenergetic（23–35 k Vp by 2 k Vp intervals） X-ray beams. Moreover, breast tissue composition ranging from about0% glandular（about 100% adipose） to 100% glandular（0% adipose） was also covered. The successful parameterization of Dg N look-up table function of the breast thickness and energy, will compact its analytical form without loss of accuracy. All parameterization fits resulted in r2 values of 0.999 or better.
基金
Supported by the National Plan for Science,Technology and Innovation(MAARIFAH)
King Abdulaziz City for Science and Technology,Kingdom of Saudi Arabia(No.1827)
