Multi Source E-Beam kV X-Ray Tube for Image-Guided Radiotheraphy

 描述(由申请人提供)：该项目将开发一种商业产品，该产品将首次在放射治疗过程中以具有吸引力的价位实现实时肿瘤跟踪，并最大限度地减少对标准临床实践的干扰。关键的新技术是一种优化的多源X射线管，它有19个焦点，放置在放射治疗系统的多叶准直器(MLC)下面，如下所示。通过将聚焦的电子束(电子束)依次引导到一系列19个冷却的钨靶上，该系统将提供一组投影图像，这些图像可以重建为围绕辐射目标的20厘米×20厘米×20厘米的数字断层合成(DTS)体积图像。投影X射线由通用的千伏成像器捕获，该成像器可以记录与层析千伏图像序列隔行的入射毫伏图像。由于放射源位于MLC周围，因此产生的断层横截面图像垂直于治疗束的轴线对齐。这种几何图形被称为“波束眼视图”成像。DTS图像将用于近乎实时地为MLC编程提供肿瘤表面的精确参考坐标。该系统的初步技术指标表明，空间分辨率接近1毫米的每秒2-3个体积图像的重复率将是可能的。多源电子束X射线管将由开发最初的Imatron EBCT扫描仪和更新的电子束行李扫描仪的主要团队开发。由TeleSecurity Sciences，Inc.的科学家、顾问和供应商组成的电子束团队与加州大学戴维斯分校一流的锥束CT团队和一名关键的瓦里安顾问合作，他们是平板X射线成像仪的权威，特别是TrueBeam龙门式千伏-中压成像仪中的TumoTrakTM的侧视图，该成像仪将用于该项目，以提供同时的MV门户成像和肿瘤位置的隔行千伏DTS成像。该项目的第一阶段扩大了前期工作，以便更准确地确定未来商业系统的最终设计规范，该系统将适用于整个放射治疗行业。第二阶段的资金将开发一种合适的多源电子束X射线管的原型，这将证明该商业系统的可行性和性能。大多数放射治疗供应商都为这一项目提供了指导和支持函。拟议的系统在未来放射治疗系统中的商业实施将允许治疗计划大大改善辐射暴露在恶性肿块表面边界以外的减少边缘内的定位，同时相应地减少对周围正常结构的暴露。这对于在自由呼吸期间治疗胸部和上腹部肿瘤尤其重要，在这些肿瘤中，经常会遇到2厘米到5厘米的周期性运动。

 DESCRIPTION (provided by applicant): This project will develop a commercial product that will enable for the first time realtime tumor tracking during radiotherapy at an attractive price point and with minimal interference with standard clinical practice. The key novel technology is an optimized multi-source X-ray tube with 19 focal spots that is placed below the multi-leaf collimator (MLC) of a radiotherapy system as shown below. By steering a focused electron beam (e-beam) on a series of 19 cooled tungsten targets in sequence, this system will provide a set of projection images that can be reconstructed into a 20 cm × 20 cm × 20 cm digital tomosynthesis (DTS) volume image that surrounds the radiation target. The projection X-rays are captured by a universal kV-MV imager that can record portal MV images interlaced with the sequence of tomographic kV images. Since the sources are positioned around the perimeter of the MLC, the resulting tomographic cross section images are aligned perpendicular to the axis of the therapy beam. This geometry is referred to as "Beam's Eye View" imaging. The DTS images will be used to provide precise reference coordinates of a tumor surface for programming of the MLC, in near real-time. The preliminary specifications for the system indicate that a repetition rate of 2-3 volume images per second with near 1 mm spatial resolution will be possible. The multi-source e-beam X-ray tube will be developed by substantially the same premier team who developed the original Imatron EBCT scanners and the more recent e-beam luggage scanner. The e-beam team consisting of TeleSecurity Sciences, Inc. scientists, consultants, and vendors has partnered with the premier cone beam CT team at UC Davis along with a key Varian consultant, who are authorities on flat panel X-ray imagers, and in particular the Side-view of the TumoTrakTM in a Truebeam gantry kV-MV imager that will be used in this project to provide simultaneous MV portal imaging with interlaced kV DTS imaging of the tumor position. Phase 1 of the project extended the preliminary work to more precisely define the final design specifications for a future commercial system that will be appropriate for the entire radiotherapy industry. Phase 2 funding will develop a suitable prototype of the multi-source eBeam X-ray tube which will demonstrate the feasibility and performance of the commercial system. The majority of radiotherapy vendors have provided guidance and letters of support for this project. The commercial implementation of the proposed system in future radiotherapy systems will permit treatment plans that will have far improved localization of radiation exposure within reduced margins beyond the apparent boundaries of a malignant mass with a corresponding reduction in exposure to surrounding normal structures. This will be especially important in treating tumors of the chest and upper abdomen during free breathing where periodic motion in the range of 2 cm to 5 cm is often encountered.