Small Animal Irradiator with Cone Beam CT

描述(由申请人提供)：这项提案要求资金购买最先进的小动物辐射研究平台(SARRP)辐照器。SARRP是第一个商业化的同类产品，它将锥束计算机断层扫描(CT)成像与微照射相结合，使基础科学家和转化型研究人员能够利用目前临床上用于小动物研究的适形、分次放射治疗方案。这对于将放射治疗与化疗或免疫疗法相结合的实验室研究的翻译是至关重要的。研究辐射对正常组织的影响也需要高度适形放射治疗。在许多情况下，目标是限制对一个器官(例如心脏)或器官的一部分(例如一个肺或一个肾脏)的辐射暴露，以便于分析正常组织损伤，而不会混淆其他正常组织损伤的影响或使用不切实际的高单一辐射剂量。目前在弗吉尼亚联邦大学有一台Cs137辐照器，一台退役的临床Co60装置和临床直线加速器(Linasc)。由于成本和安全问题，Co60单元正在退役。Cs137辐照体不提供保形剂量分布。临床配置的直线加速器不具有SARRP的共形特性，而SARRP对小动物研究是最佳的。此外，它们只能在门诊时间之后进行手术，而且总是存在对患者安全的担忧(例如过敏)。SARRP将被安装在梅西癌症中心的间隔室，最大限度地减少有价值的转基因小鼠从“干净的”间隔室外的运输。主要使用者是美国国立卫生研究院资助的，来自放射肿瘤学、人类遗传学、生物化学、神经外科和药理学/毒理学的部门。他们的研究范围从乳腺癌、前列腺癌和结肠癌的研究，到包括结肠、肺和心脏在内的正常组织反应的研究，并将放射治疗与化疗或免疫治疗相结合。一名研究人员正在弗吉尼亚联邦大学分子成像设备中使用为小动物研究设计的PET/CT扫描仪进行PET(正电子发射断层扫描)研究。有了SARRP可以容纳的适当的图像配准，利用弗吉尼亚联邦大学回旋加速器合成的探针进行的缺氧或肿瘤细胞增殖的PET成像可以用于开发使用SARRP的生物引导放射治疗方案。对于所有的研究来说，将精确的适形辐射传递到肿瘤或正常组织的能力对于在体内测试机械假说并将其转化为可测试的治疗方案至关重要。

DESCRIPTION (provided by applicant): This proposal requests funds for the purchase of a state of the art small animal radiation research platform (SARRP) irradiator. SARRP is first of its kind that is commercially available and that combines cone beam computed tomography (CT) imaging with micro-irradiation enabling basic scientists and translational researchers to utilize the conformal, fractionated radiotherapy protocols that are currently used in the clinic in studies with small animals. This is essential for translating laboratory studies that combine radiotherapy with chemo- or immunotherapies. Studies on the normal tissue effects of radiation also require highly conformal radiation treatments. The goal in many cases is to limit radiation exposure to one organ (e.g. the heart) or part of an organ (e.g. one lung or one kidney) to facilitate analysis of normal tissue damage without confounding effects of other normal tissue damage or using unrealistically high single radiation doses. Presently at Virginia Commonwealth University there is a Cs137 irradiator, a retired clinical Co60 unit and the clinical linear accelerators (linasc). The Co60 unit is being decommissioned because of cost and security issues. The Cs137 irradiator does not provide conformal dose distributions. The linacs in their clinical configurations do not have the conformal properties of the SARRP that are optimal for small animal studies. In addition, they can be only operated after clinic hours and there are always the concerns of patient safety (e.g allergies). The SARRP will be installed in the Massey Cancer Center vivarium minimizing transport of valuable transgenic mice outside the "clean" vivarium. The major users are NIH funded and come from the Departments of Radiation Oncology, Human Genetics, Biochemistry, Neurosurgery and Pharmacology/Toxicology. Their studies range from studies with breast, prostate and colon cancers to studies of normal tissue responses including colon, lung, and heart and combine radiotherapy with either chemotherapeutics or immunotherapy. One investigator has on-going studies on PET (Positron Emission Tomography) using a PET/CT scanner designed for small animal studies in the Molecular Imaging Facility at Virginia Commonwealth University. With appropriate image registration which the SARRP can accommodate, PET imaging for hypoxia or tumor cell proliferation with probes synthesized in the cyclotron at Virginia Commonwealth University can be used to develop biologically guided radiotherapy protocols using SARRP. For all investigations the ability to deliver precise conformal radiation to either tumor or normal tissue is essential for testing mechanistic hypotheses in vivo and their translation into testable treatment protocols.