In vivo EPR for after-the-fact measurement of dose

总体目标是满足一项关键需求：在事故发生后立即确定个人是否受到可能导致急性临床症状的辐射剂量。如果暴露条件表明急性效应是可能的，我们需要能够快速准确地将个体置于适当的剂量类别，以指导治疗方法和咨询。随着减轻电离辐射损害的程序的可能发展，确定谁处于危险之中的必要性变得更加紧迫，因为这种干预措施在尽早使用时可能最有效。当暴露于 如果被发现处于不太可能导致急性影响的范围内，则测量的可用性将提供保证并减少进入医疗保健系统的人数。有大量的数据表明，在体内EPR剂量测定，基于牙齿中的辐射诱导效应，具有的灵敏度和准确性，以满足这种事后定量剂量评估的需求的主要部分，提供有效的筛选信息和即时读数在不到五分钟。在这个项目中，我们提出了一套相关的具体目标，以（a）满足当前的需求和（B）追求长期发展，以提高能力。最迫切需要的是一种可实地部署的仪器， 快速“事后”剂量测定法。这将是我们的首要任务。我们最初将使达特茅斯的现有设施完全用于紧急剂量测定，并将利用这些设施和进一步的改进作为快速开发适合现场使用的可移动剂量计的基础。这将在罗切斯特进行测试，在那里，它也将用于扩展校准/确认，使用那里的专业知识和患者人群。还有一些可行的方法可以提高该方法的灵敏度和实地部署能力;将在不影响首要优先事项的情况下尽可能有效地进行这些工作。这些包括 手持式剂量计的潜在开发，以及几种有希望提高灵敏度的方法。这种灵敏度的提高将进一步减少进行测量所需的时间，并使我们能够将该方法扩展到较低的阈值，可能远远低于可能导致急性临床效应的剂量。也有一些合理的手段，以补充体内EPR剂量测定法进行测量，在体外，使用头发，手指/脚趾甲，或非常小的芯片的牙齿。这些测量可以扩大筛查能力，也有助于解决不对称照射问题。

The overall objective is to meet a critical need: determining immediately after an incident whether individuals have received a radiation dose that could result in acute clinical symptoms. If the exposure conditions indicate that acute effects are possible, we need to be able to place individuals into appropriate dose categories rapidly and accurately, to guide therapeutic approaches and counseling. With the potential development of procedures to mitigate damage from ionizing radiation, the need to determine who is at risk is even more urgent, since such interventions are likely to most effective when used as early as possible. When exposures are found to be in a range that is unlikely to lead to acute effects, the availability of the measurement will provide reassurance and reduce the number of people entering the medical care system. There are substantial data available that indicate that in vivo EPR dosimetry, based on radiation-induced effects in teeth, has the sensitivity and accuracy to meet a major part of the needs for such after-the-fact quantitative dose assessment, providing effective screening information and immediate readouts in less than five minutes. In this project, we propose a set of related specific aims to (a) address the immediate needs and (b) pursue longer-term developments to enhance capabilities. The most urgent need is a field deployable instrument for rapid "after-the-fact" dosimetry. This will be our first priority. We initially will make the existing facility at Dartmouth fully operational for emergency dosimetry, and will use these and further improvements as the basis for the rapid development of a transportable dosimeter suitable for field use. This will be tested at Rochester, where it also will be used for extending calibrations/validations, using the expertise and patient populations there. There also are a number of feasible ways to improve the sensitivity and field deployability of the method; these will be pursued as efficiently as possible without affecting the first priorities. These include the potential development of a hand-held version of the dosimeter, and several promising methods to enhance sensitivity. Such increases in sensitivity will further reduce the time needed to make the measurements and enable us to extend the method to a lower threshold, potentially to doses well below those that can cause acute clinical effects. There also are some plausible means to complement in vivo EPR dosimetry by making measurements in vitro, using hair, finger/toenails, or very small chips of teeth. These measurements could broaden the capacity for screening, and also aid in resolution of asymmetric exposures.