Calculation of Neutron Microdosimetry Spectra in Some Real Tissues Compared to Alternative Tissue Equivalent Materials

Microdosimetry studies are a description to better understand the mechanisms of biological effects of ionizing radiation to improve cancer and minimize environmental and occupational hazards. Due to the impossibility of studying living human organs, and reducing animal experimentation, microdosimeter walls are made of alternative tissue-equivalent materials such as A-150 tissue-equivalent plastic and polyethylene to obtain experimental results. In order to measure dose and dose distribution with high accuracy in micron dimensions in body tissues, it is necessary to investigate microdosimetric quantities and determine under what conditions these alternative materials can be used instead of tissues. In this article, by using the Geant4 simulation code, we have studied the relative difference of the studied quantities in microdosimetry of A-150 tissue-equivalent plastic and polyethylene with three major body tissues including soft, fat and compact (cortical) bone tissue and for this purpose, we simulated the microdosimeter of right cylinders with 2 microns’ sizes for neutron beam with energies of 0.1, 1, and 10 MeV. We observed that the maximum relative difference percentage of the frequency-mean lineal energy of soft, fat, and compact bone tissue in comparison with polyethylene is 6.26, 6.3, and 12.89%, respectively. It in comparison with A-150 tissue-equivalent plastic is 3.21, 3.25, and 13.75%, respectively. Therefore, we can use these alternative materials instead of the mentioned tissues by applying these corrections. We found that the use of alternative tissue equivalent materials depends on the neutron energy and tissue type; full details are reported in the text of the article.