基于染色体畸变的细胞存活模型研究

为评估质子和重离子的辐射生物效应，建立了基于染色体畸变的细胞存活机理模型。开发了纳剂量生物物理蒙特卡罗模拟程序（NASIC）的DNA损伤修复模块，用于模拟不同射线类型、不同传能线密度（LET）辐射所致细胞核内染色体畸变产额。在分析辐射所致染色体畸变产额规律的基础上，建立了基于染色体畸变的细胞存活机理模型，并根据细胞存活实验数据拟合模型参数。以V79细胞为例，对于X射线和不同LET的质子，细胞存活分数的模型计算值与实验数据符合得很好，相关系数为0.985 3。采用⁴He离子的实验数据对模型及参数进行了验证，模型计算值与实验数据的相关系数为0.931 1。可见，模型能较好地区分不同射线类型、不同LET辐射在细胞致死效应上的差异。

Modelling of Cellular Survival Following Chromosome Aberration

In order to assess the biological effectiveness of protons and heavy ions, a mechanistic model of cellular survival following radiation-induced chromosome aberrations was proposed. DNA damage repair module of nanodosimetry biophysical Monte Carlo simulation code (NASIC) was developed to simulate chromosome aberrations in nucleus induced by different types of particles at different linear densities of energy transfer (LET). Based on the analysis of radiation-induced chromosome aberration, a mechanistic model of cellular survival following radiation-induced chromosome aberrations was proposed. The parameters of the model could be obtained by fitting the experimental data of cell survival curves. For V79 cells exposed to X-rays and protons at different LET, the cell survivals calculated with the proposed model are in good agreement with the experimental data, and the correlation coefficient is 0.985 3. The proposed model was validated by experimental data of V79 cells exposed to ⁴He ions and the correlation coefficient of the cell survival calculated with the proposed model, and the experimental data is 0.931 1. The results show that the proposed model can distinguish the difference of cell survival for cells exposed to different types of particles at different LET.