Robotic SPECT for Biological Imaging Onboard Radiation Therapy Machines

描述（由申请人提供）：该项目的广泛长期目标是提供放射治疗机上的生物成像-即癌症患者处于治疗位置时的生物成像。目前的机载靶定位主要基于X射线透射成像，其对生物学不敏感并且不能识别某些肿瘤。除了靶定位之外，还提出了基于诸如缺氧的生物功能来修改剂量。对于这些任务，机载生物成像可以由单光子发射计算机断层扫描（SPECT）提供。SPECT在其成像癌症相关生物学的能力方面正在迅速发展，例如缺氧、血管生成、细胞增殖、代谢、表皮生长因子受体、细胞凋亡和多药耐药性。低成本的SPECT可以被设计到放射治疗室。SPECT示踪剂是广泛可用的，双示踪剂SPECT成像是可能的，并且SPECT系统具有成像正电子发射体（诸如F-18）的潜力。机载SPECT的任务是将生物功能定位在一个小体积内，其大致位置是已知的其他定位程序。机载SPECT的实现受到有限时间（d 5分钟）和治疗室几何约束的挑战。将开发新的SPECT方法来解决这些任务和挑战。目标是：（1）开发一个原型系统--由一个紧凑的核医学探测器和一个机械臂组成--可以在病人周围操纵探测器进行放射治疗。(2)设计用于有限体积的机载平行孔和针孔SPECT成像的轨迹，并使用机器人/探测器系统来评估这些轨迹的任务性能。 这些目标涉及不仅对机载SPECT而且对一般SPECT重要的技术发展。目标（1）实现了常规SPECT机架不可能实现的探测器轨迹。目标（2）开发和探索新的探测器轨迹和新硬件实现它们的能力。这项工作将推动SPECT向新的方向发展，实现放射治疗中的实时生物靶向，并有可能改善治疗结果。

DESCRIPTION (provided by applicant): The broad long-term objective of this project is to provide biological imaging onboard radiation treatment machines - that is, biological imaging as the cancer patient is in treatment position. Current onboard target localization is based mainly on x-ray transmission imaging, which is not sensitive to biology and cannot identify some tumors. In addition to target localization, it has also been proposed that dose be modified based on biological function such as hypoxia. Onboard biological imaging - for these tasks - could be provided by single-photon emission computed tomography (SPECT). SPECT is evolving rapidly in its ability to image cancer-relevant biology, such as hypoxia, angiogenesis, cell proliferation, metabolism, epidermal growth factor receptor, apoptosis, and multi-drug resistance. Low-cost SPECT can be engineered to the radiation treatment room. SPECT tracers are widely available, dual-tracer SPECT imaging is possible, and SPECT systems have potential to image positron emitters such as F-18. The onboard SPECT task is to localize biological function within a small volume whose approximate location is known by other localization procedures. Realization of onboard SPECT is challenged by limited time (d 5 minutes) and by geometrical constraints of the treatment room. Novel SPECT methods will be developed to address these tasks and challenges. The Aims are: (1) Develop a prototype system - comprised of a compact nuclear-medicine detector and a robotic arm - that can maneuver the detector about a patient in position for radiation therapy. (2) Design trajectories for onboard parallel-hole and pinhole SPECT imaging of limited volumes, and use the robot/detector system to evaluate task performance of these trajectories. These Aims involve technological developments important not only for onboard SPECT but for SPECT generally. Aim (1) enables detector trajectories that are not possible with conventional SPECT gantries. Aim (2) develops and explores new detector trajectories and the ability of the new hardware to implement them. This work will advance SPECT in novel directions, allowing real-time biological targeting in radiation therapy, and potentially improving treatment outcome.