The aim of this work was to study photon and electron dose distributions in a phantom filled with water using the Monte Carlo Geant4 tool for electron energies ranging from 1 to 21 meV and for photon energies ranging from 1.25 meV to 25 meV, corresponding to conventional radiotherapy Linac energies. The results of the Geant4 calculations were validated based on the relevant experimental data previously published. The results obtained were fitted and analytical models of dose distributions were developed for gamma radiation and electrons. For each of these models, one-dimensional (including dose depth profiles as a function of the depth inside the phantom) and two-dimensional (including the dose distribution as a function of depth and lateral position inside the phantom) dose distributions have been considered. Results are presented for photons and electrons of various energies. The coefficient of determination \(R^{2}\) illustrates an excellent match between the developed analytical model and the Geant4 results. It is demonstrated that the analytical models developed in the present study can be applied in various fields such as those used for calibration applications and radiation therapy. It is concluded that the analytical models developed allow for quick, easy and reliable clinical dose estimates and offer promising alternatives to the standard tools and methods used in radiotherapy for treatment planning.

这项工作的目的是使用Monte Carlo Geant4工具研究充满水的幻影中光子和电子的剂量分布，其电子能量范围为1到21 meV，光子能量范围为1.25 meV到25 meV，这与常规放射疗法相对应直线加速器能量。根据先前发布的相关实验数据验证了Geant4计算的结果。拟合得到的结果，并为伽马辐射和电子建立剂量分布的分析模型。对于这些模型中的每一个，都考虑了一维（包括剂量深度分布作为幻像内部深度的函数）和二维（包括剂量分布作为深度与幻象内部深度的函数）的剂量分布。给出了各种能量的光子和电子的结果。确定系数\（R ^ {2} \）说明了开发的分析模型与Geant4结果之间的出色匹配。结果表明，本研究开发的分析模型可以应用于各种领域，例如用于校准应用和放射治疗的领域。结论是，开发的分析模型可实现快速，简便和可靠的临床剂量估算，并为放射疗法中用于治疗计划的标准工具和方法提供了有希望的替代方法。