Nunes J, Prestwich W V, Kwok C S
Department of Physics, McMaster University, Hamilton, Ontario, Canada.
Med Phys. 1993 Jul-Aug;20(4):1243-50. doi: 10.1118/1.596975.
Beta-ray dose backscatter factors or dose ratios at planar soft-tissue boundaries were calculated using the EGS4/RESTA and CYLTRAN (version 2.1) Monte Carlo codes and these data were compared with experimental results. Since the beta-ray source was 32P, this work addressed the transport of, and energy deposition by, electrons less energetic than 2 MeV. In particular, the simulations targeted the codes' performances with regard to the transport of low energy electrons across material boundaries and the backscattering of low energy electrons. In general, backscatter factors calculated at 7.25 mg/cm2 from several soft-tissue interfaces agreed with experimental values to within about five percent. CYLTRAN was also used to calculate the variation of backscatter factor with distance from aluminum/soft-tissue and air/soft-tissue interfaces and was found to reproduce the shapes of experimental backscatter factor depth profiles.
使用EGS4/RESTA和CYLTRAN（版本2.1）蒙特卡罗代码计算平面软组织边界处的β射线剂量反向散射因子或剂量比，并将这些数据与实验结果进行比较。由于β射线源为32P，这项工作研究了能量低于2 MeV的电子的传输和能量沉积。特别是，模拟针对代码在低能电子跨材料边界传输和低能电子反向散射方面的性能。一般来说，从几个软组织界面在7.25 mg/cm2处计算的反向散射因子与实验值的误差在约5%以内。CYLTRAN还用于计算反向散射因子随距铝/软组织和空气/软组织界面距离的变化，发现其能重现实验反向散射因子深度分布的形状。
