Biodosimetry based on EPR measurements of teeth in vivo Dartmouth Medical School

项目总结（见说明）： 我们最近已经证明了在活体受试者中原位和体内进行指甲测量的可行性，使得避免需要修剪指甲来进行指甲剂量测定是可行的，而是使用新型谐振器进行测量，该谐振器可以在高频（9.5GHz或“X波段”）下直接在体内指甲上进行灵敏测量。我们将充分确定在需要应用于现场的条件下，在感兴趣的剂量范围内具有足够准确度和灵敏度的测量的可行性和能力，然后确定哪些参数可能影响剂量反应关系，开发科普这些因素的方法，开发基于体内测量的快速准确剂量测定方案，然后为一个功能齐全的EPR剂量测定仪器的可克隆原型制定标准。我们建议使该仪器能够由非专业用户操作。这些研究将利用我们在人类受试者体内进行牙齿剂量测量的经验，以及我们在修剪指甲中进行体外EPR测量的经验。 由于测量是基于电离辐射的物理效应，因此预计可以在暴露后几周内的任何时间进行测量。这些变化在暴露后立即出现，并持续数周，如果发生事件，可以立即进行测量和分析。这些变化也不受此类事件后人群中可能存在的因素的影响，因此将与基于生物的生物剂量测定法互补和协同。本项目的测量结果将为项目2的进展提供一个关键因素，促进对指甲中机械诱导EPR信号的起源和分布的理解。仪器核心将提供谐振器的发展的关键部分，并最终在一个敏感的X波段EPR光谱仪的建设，使在外地的测量。TBI核心将为体内照射指甲的患者组提供必要的通路。仪器开发和原型仪器的构建将与Cores A、C和E合作进行。

PROJECT SUMMARY (See Instructions): We recenfiy have demonstrated the feasibility of making measurements of nails in living subjects in situ and in vivo, making it feasible to avoid the need for clipping nails to carry out nail dosimetry, instead making the measurements with a new type of resonator that can make sensifive measurements at a high frequency (9.5 GHz or "X-Band") directly on the nail in vivo. We will determine fully the feasibility and capability of measurements with sufficient accuracy and sensifivity within the dose range of interest under the conditions that would be needed to apply in the field and then determine what parameters may affect the doseresponse relationships, develop methods to cope with these factors, develop a protocol for fast and accurate dosimetry based on measurements in vivo, and then develop criteria for a clonable prototype of a fully functional EPR dosimetry instrument. We propose to make this instrument capable of being operated by non-expert users. The studies will ufilize our experience in making measurements in vivo with human subjects for tooth dosimetry and our experience in making EPR measurements in vitro in clipped nails. Because the measurements are based on a physical effect of ionizing radiafion, it is expected that they can be made at any time after the exposure within a window of several weeks. These changes are present immediately after exposure and persist for a period of a few weeks allowing measurements to be immediately taken and analyzed If an event did occur. The changes are also unaffected by factors that are likely to be present in the population after such an event and therefore will be complementary and synergistic to biologically based biodosimetry. The results of the measurements in this project will provide a crifical element for the advancement of project 2, advancing understanding of the origins and distribufions of the mechanically-induced EPR signals in nails. The instrumental core will provide critical parts of the developments of the resonators and ultimately in the construction of a sensitive X-Band EPR spectrometer for making the measurements in the field. The TBI core will provide essential access to the patient group with nails irradiated in vivo. The instrumental developments and the construction of the prototype instrument will be carried out in collaboration with Cores A,C , and E.