EFFECT OF TARGETED LOW DOSE RADIATION TREATMENT ON TUMOR OXYGENATION

靶向低剂量放射治疗对肿瘤氧合的影响

• 批准号: 6353194
• 负责人: ROSALYN D BLUMENTHAL
• 金额: $ 1.22万
• 依托单位: DARTMOUTH COLLEGE
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2002-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6353194
• 关键词: Mammalia; biomedical resource; environmental toxicology; human tissue; oral pharyngeal; radiology; technology /technique

The long-term purpose of this research is to determine the feasibility of using in vivo EPR to assess radiation does in accidental exposures to radiation. The current research focuses on the feasibility of using low frequency (L-band) EPR spectroscopy for the measurement of long-lived radiation-induced EPR signals in the teeth of living rats and to compare this with similar measurements in isolated human teeth. The radiation-induced EPR signal in teeth has distinctive characteristics based on its shape and power saturation. The use of teeth also has the advantage of providing a site where very good geometry with a sensitive resonator can readily be achieved for entirely non-invasive measurements in vivo. These results suggest that it may be possible to develop techniques and instruments that will allow these measurements eventually to be made non-invasively in humans. We now have completed the initial measurements of radiation-induced signals from the teeth of living rats and isolated human teeth. Initially the signal intensity from rat teeth which received X-ray radiation was quite weak due to its very small size and weight (about 100mg), so while it was detectable with X-band EPR, very high doses were needed to observe it with L-band. We therefore made a new loop resonator specially designed for rat teeth and this increased the sensitivity to a useful level. We also used the new resonator to obtain data from isolated human teeth with a present limit of detection of about 1Gy. Further technical developments should extend this to even lower doses. We conclude that human in vivo EPR dosimetry will be feasible.

这项研究的长期目的是确定 使用体内 EPR 评估辐射剂量的可行性 意外暴露于辐射。 目前的研究重点是 使用低频（L 波段）EPR 光谱进行分析的可行性 长寿命辐射感应 EPR 信号的测量 活体老鼠的牙齿，并将其与类似的测量结果进行比较 孤立的人类牙齿。 牙齿中辐射引起的 EPR 信号 基于其形状和功率饱和的独特特征。 使用牙齿的另一个优点是提供了一个非常适合的场所。 具有灵敏谐振器的良好几何形状可以很容易地实现 完全无创的体内测量。 这些结果表明 开发技术和仪器是可能的 最终将允许这些测量以非侵入方式进行 人类。 现在我们已经完成了初步测量 来自活体大鼠牙齿和分离的辐射诱导信号 人类的牙齿。 最初来自大鼠牙齿的信号强度 由于其尺寸非常小，所接收到的 X 射线辐射相当微弱 重量（约 100 毫克），因此虽然可以用 X 波段 EPR 检测到，但非常 需要高剂量才能用L波段观察它。 因此我们做了一个 专为大鼠牙齿设计的新型环形谐振器，这增加了 敏感度达到有用的水平。 我们还使用了新的谐振器 从孤立的人类牙齿中获取数据，目前的限制是 检测约1Gy。 进一步的技术发展应扩展 这甚至可以降低剂量。 我们得出结论，人类体内 EPR 剂量测定将是可行的。