TUNABLE X-RAY CANCER PHOTOTHERAPY

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。我们希望验证这样的假设，即在肿瘤细胞内与底物结合的各种重金属的k边缘及以上的单色x射线辐射在体外杀死肿瘤细胞方面比传统放射治疗更有效。该项目是SLAC速调管部门康普顿光源（CLS）项目的一部分，旨在开发一种可调、紧凑的准单能x射线源，用于癌症检测和治疗。在开发CLS时，我们建议使用斯坦福同步辐射实验室（SSRL）的光束线来研究x射线光疗的剂量增强。提议的工作将使用SSRL光束线照射用高z原子标记的已建立的细胞系。剂量增强将通过传统菌落计数和生物发光试验产生的剂量-反应曲线来评估。放射性增敏剂的候选物包括碘、钆、铟、铂和金。样品将在这些元素的k边以上以0-30 keV的能量照射。虽然SSRL光束线在这些能量下产生相对较低的通量，但细胞培养的几何形状可以调整到小光束尺寸，并且样品可以长时间（小时）照射以达到更高的集成光子强度。为了达到更高的通量，在这些实验中允许更宽的带宽（高达1kev）。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We wish to test the hypothesis that monochromatic x-ray radiation at and above the K-edge of various heavy metals bonded to substrates within neoplastic cells is more effective that conventional radiation therapy for killing neoplastic cells in vitro. This program is part of the Compton Light Source (CLS)project at the SLAC Klystron Department to develop a tunable, compact source of quasi-monoenergetic x-rays for use in cancer detection and treatment. While the CLS is under development, we propose to use a beamline at the Stanford Synchrotron Radiation Laboratory (SSRL) for studying dose enhancement in x-ray phototherapy. The proposed work will use an SSRL beamline to irradiate established cell lines labeled with high-Z atoms. Dose enhancement will be assessed through dose-response curves generated both by traditional colony counting and by bioluminescence assay. Candidates for radiosensitizing agents include Iodine, Gadolinium, Indium, Platinum, and Gold. Saples will be irradiated at energies 0-30 keV above the K-edges of these elements. Although SSRL beamlines produce relatively low fluxes at these energies, cell culture geometry can be adjusted to the small beam size, and samples may be irradiated for long times (hours) to reach higher integrated photon intensities. Broader bandwidths (up to 1 keV) are permitted in these experiments as a trade-off for reaching higher fluxes.