C-arm Fluoroscopy for Prostate Brachytherapy

描述（由申请人提供）：在前列腺癌治疗过程中，提出了一种技术，用于开发术中c臂透视图像的三维注册，具有空间注册的超声可视化和放射性植入物的植入指导以及在线植入物评估。在目前的经直肠超声引导近距离治疗技术下，术中植入种子的软组织解剖定位仍然是一个未解决的问题。超声（US）图像对相关软问题提供了满意的区分，但植入的近距离治疗种子在US图像中无法清晰识别。目前，60%的从业者使用术中c臂透视作为植入物的定性检查。虽然种子可以在x射线上精确定位，但投影的腔内图像不能显示软组织解剖结构。因此，临床长期需要将c臂的相关信息与美国引导的输送系统结合起来，以安全、可靠和经济的方式。本研究的目的是在使用c臂x线透视的经直肠美国引导前列腺近距离放射治疗中实施术中剂量学质量保证。该计划的具体目标是将c臂x线透视图像确定的植入种子的空间位置与超声图像确定的软组织解剖结合起来。这将使实际剂量分布与预先计划的剂量进行比较，并在植入过程中进行评估。因此，立即的治疗干预将有可能纠正任何“冷”区域或最小化关键结构附近的“热”区域，并在治疗体积内精确地“匹配”最佳源位置。

DESCRIPTION (provided by applicant): A technique is proposed for the development of an intraoperative, 3-dimensional registration of C-arm fluoroscopic images with spatially-registered ultrasound visualization and implant guidance of radioactive implants and on-line implant assessment during the procedure for treatment of prostate cancer. With present techniques using transrectal ultrasound guidance for brachytherapy, intra-operative localization of implanted seeds with respect to soft tissue anatomy is still an unsolved problem. Ultrasound (US) images provide satisfactory differentiation of relevant soft issue, but implanted brachytherapy seeds cannot be clearly identified in the US images. Currently sixty percent of the practitioners use intra-operative C-arm fluoroscopy as a qualitative check of the implants. While seeds can be accurately localized in X-ray, projected transluminal images do not reveal soft tissue anatomy. Hence, there is a standing clinical need to couple relevant information from C-arm with the US-guided delivery system, in a safe, robust, and cost-efficient manner. The goal of the proposed work is to implement intra-operative dosimetric quality assurance in transrectal US-guided prostate brachytherapy with the use of C-arm X-ray fluoroscopy. The specific objective of this program is to incorporate spatial location of implanted seeds determined from C-arm X-ray fluoroscopy images with soft tissue anatomy determined from ultrasound images. This will enable the actual dose distribution to be compared to the dose pre-plan and assessed while the implant process is underway. Thus, immediate therapeutic intervention would be possible to correct for any "cold" regions or minimize "hot" regions near critical structures and exactly "match" the optimal source placement within the treatment volume. The outcome of this research could be of immediate benefit in the treatment of prostate cancer. It would provide the ability to visualize in real time the placement of implants, providing implants which reflect optimal dosimetry. A large group of patients with early-stage disease are candidates.