Radiation induced cancer risk reduction as a function of dose protraction: interspecies comparison

电离辐射(IR)会对生物造成损害。不同总剂量和不同剂量红外线对健康的影响 提供IR的剂量率必须通过基于整个生物体的统计分析来定义 如罹患癌症风险增加或寿命缩短风险增加等终点。这个 如果延长，总剂量可以增加的系数，以达到相同的最终生物效应，称为 剂量和剂量率效应因子(DDREF)。全人类接收到的累积持久辐射 美国的人口非常多，属于政府规定的监管政策。这些政策 依靠国家和国际机构使用DDREF评估IR潜在危险的工作 值作为考虑长期红外线暴露的关键输入因素之一。最终，政府 职业性和公共性红外线照射的规定限值(主要是延长的)和X射线的建议 基于医疗诊断程序(大多是低总剂量)都取决于当前接受的DDREF值。 使用计算工具和关于急性和长期暴露的动物数据，我们发现DDREF 此时使用的估计是不适当的(Haley等人)。2015)，但剂量率效应系数(DREF) 可以使用大量的动物数据进行评估。在这个项目中，我们建议使用物种间比较来 改进(1)外束DREF值和(2)放射性核素剂量/质量/给药途径剂量率 对特定类型的辐射诱发癌症的有效系数(DREF)(以及从内部到外部的寿命缩短 发射器)。鉴于几个国际机构正在寻求改变，这一点尤其重要 DDREF的价值-ICRP专门发给我们小组的一封信，支持这项工作的重要性是 附加到应用程序。

Ionizing radiation (IR) causes damage to living organisms. The health effects of IR for different total doses and dose rates at which IR was delivered have to be defined by statistical analyses based on whole organism endpoints such as an increase in the risk for development of cancer or an increased risk of life shortening. The factor by which a total dose could be increased, if protracted, for the same final biological effect, is known as dose and dose-rate effectiveness factor (DDREF). The cumulative protracted radiation received by the entire population of USA is very large and falls under regulatory policies that are government defined. These policies rely on the work of national and international agencies evaluating potential dangers of IR using the DDREF value as one of the key input factors for consideration of protracted IR exposures. Ultimately, government regulated limits for occupational and public IR exposures (mostly protracted) and recommendations for X-ray based medical diagnostic procedures (mostly low total doses) all depend on currently accepted DDREF value. Using computational tools and animal data on acute and protracted exposures we found that the DDREF estimate used at this time is inappropriate (Haley et al. 2015) but that dose-rate effectiveness factor (DREF) can be evaluated using extensive animal data. In this project we propose to use interspecies comparisons to refine (1) external beam DREF values and (2) radionuclide dose/quality/route of administration dose rate effectiveness factors (DREF) for specific types of radiation induced cancers (and life shortening from internal emitters). This is especially important in light of the fact that several international bodies are looking to change values for DDREF– a letter from ICRP sent specifically to our group supporting the importance of this work is attached to the application.