Abstract
ABSTRACT In this dissertation, the cellular S value and lineal energy were evaluated for various charged particles, including alpha particles, electrons, and those from radionuclides and BNCT, with the MIRD cell model. To accomplish these calculations and analyze their relative biological effectiveness(RBE), Cellular Dosimetry Program (CDP) were developed with Monte Carlo simulation and the energy-range relations under the continuous slowing down approximation(CSDA). Firstly, the calculated S values were compared with those results published in “MIRD Cellular S values” by Society of Nuclear Medicine(SNM), and their differences for alpha particles and electrons were within 1% and radionuclide mostly within 2 %, respectively. Secondly, the lineal energy distribution were analyzed with respect to their energies, cell sizes or source-target configuration for the same situation. The S value refers to the radiation quantity within the target region. By contrast, the lineal energy was an index for radiation quality which definitely described ionizing ability within the biological system. In general, the charged particle whose range equivalent to target size possesses the most lineal energy and highest RBE within the target region. Finally, the major contribution of this study is to build up the CDP system and carry out systematic research on cellular S values and microdosimetry for various charged particles. Especially, the radionuclides and BNCT were investigated, and the effective RBE of the THOR epithermal neutron beam was estimated for tumors and normal tissues of specified 10B concentrations.