Roeske J C, Stinchcomb T G
Department of Radiation and Cellular Oncology, The University of Chicago, Illinois 60637, USA.
Radiat Res. 1999 Jan;151(1):31-8.
In evaluating the efficacy of alpha-particle emitters, a cell survival curve is often determined for a particular source-target configuration. Investigators often wish to use this information about survival for a different source-target configuration which might be more appropriate for a therapeutic application. Since the population cell survival parameter, D0, is a function of the source-target configuration, it is important to determine the individual cell survival parameter, z0, which is more fundamental. Unlike D0, z0 does not depend upon the microdosimetric variations in the specific energy distribution resulting from changes in the source-target configuration. Instead it is determined by the cell sensitivity and the radiation quality. However, the calculation of z0 from the data on survival involves computing the microdosimetric specific energy distributions of the radiation. This paper describes an approximate but sufficiently accurate method for determining z0 from D0 if the first and second moments of the single-hit specific energy distributions are known or can be estimated. Examples of applications are given. This may alleviate the need for multihit microdosimetric calculations.
在评估α粒子发射体的疗效时，通常会针对特定的源 - 靶配置确定细胞存活曲线。研究人员常常希望将这些关于存活的信息用于另一种可能更适合治疗应用的源 - 靶配置。由于群体细胞存活参数D0是源 - 靶配置的函数，确定更基本的个体细胞存活参数z0很重要。与D0不同，z0不依赖于源 - 靶配置变化导致的特定能量分布中的微剂量学变化。相反，它由细胞敏感性和辐射质量决定。然而，根据存活数据计算z0涉及计算辐射的微剂量学特定能量分布。本文描述了一种近似但足够准确的方法，若已知或可估计单次击中特定能量分布的一阶和二阶矩，则可根据D0确定z0。文中给出了应用示例。这可能减少对多次击中微剂量学计算的需求。
