A Beta-Sensitive Probe System for Use in Endoscopy

以前已经开发了利用手持式β敏感探针与肿瘤放射药物（如FDG）结合指导癌症手术治疗的方法。这些技术还可以用于协助微创内窥镜检测和治疗癌症。该项目的目标是开发一种用于内窥镜的小型化β敏感探针系统。该系统（称为Endoprobe）将有三个主要子系统：beta探测器、位置跟踪器和用户界面。贝塔探测单元将由两个堆叠的表面屏障探测器组成；第一个装置检测β粒子和光子，而后探测器只检测光子（由于前探测器的屏蔽作用）。因此，后探测器的信号可以用来校正来自前探测器的信号，以产生几乎不受污染的β通量测量。该设计已成功应用于手持式β探针系统。探测器将与位置跟踪传感器一起安置在一个密封的、可消毒的单元中，该单元可以连接到内窥镜的尖端。位置跟踪系统将有助于实时监测部队的位置。来自beta探测器和跟踪系统的信息，以及来自标准内窥镜的视频信号，将被输入到计算机工作站，用于向内窥镜医师演示。因此，第三子系统是用户界面，将用于从三个来源（探测器，跟踪器和摄像机）获取数据，组合信息并在计算机监视器上显示集成图像。在项目的最后阶段，Endoprobe系统将与内窥镜配合使用，并在一系列模拟食管癌搜索中使用逼真的幽灵进行测试。选择食管癌作为研究对象，是因为据报道这种类型的癌症与FDG具有良好的亲和力，而且食管癌是一种重大的健康风险，可以通过早期发现的微创技术进行有效治疗。FDG在腹部正常器官的积累将通过充满适量FDG的拟人化躯干幻影来模拟。用一根浸泡在FDG中的软管模拟正常食管。食管病变（包括良性和恶性）将由含有适量FDG的明胶薄片模拟。这些幽灵将被加热到模拟体温，这样就可以评估环境温度升高对探测器工作特性的影响。在进行食管内窥镜检查方面有经验的医生将使用Endoprobe系统检查模拟食管。这些测试的结果将用于评估该系统及其用于检测食管癌的技术的有效性，并评估将Endoprobe应用于其他内窥镜手术的可取性。

Methods for the guidance of surgical treatment of cancer utilizing handheld beta-sensitive probes in conjunction with tumor-avid radiopharmaceuticals (such as FDG) have previously been developed. These technologies could also be used to assist in the minimally-invasive endoscopic detection and treatment of cancer. The goal of this project is the development of a miniaturized beta-sensitive probe system for use with endoscopes. This system (called Endoprobe) will have three major subsystems: beta-detector, position-tracker and user interface. The beta detection unit will consist of two stacked surface barrier detectors; the first device detects beta particles and photons, while the rear detector only detects photons (due to the shielding effects of the front detector). Thus, the rear detector's signal can be used to correct the signal from the front detector to produce a virtually uncontaminated measure of beta flux. This design has been successfully employed in handheld beta probe systems. The detectors will be housed with a position-tracking sensor inside a sealed, sterilizable, unit that can be attached to the tip of an endoscope. The position-tracking system will facilitate real-time monitoring of the unit's location. Information from the beta det4ector and tracking system, in addition to the video signal from a standard endoscope will be input to a computer workstation for presentation for presentation to the endoscopist. Thus, the third subsystem is the user interface that will be used acquire data from the three sources (detector, tracker and video camera), combine the information and display the integrated image on a computer monitor. In the final stage of the project, the Endoprobe system will be mated with an endoscope and tested in a series of simulated searches for esophageal cancer using realistic phantoms. The search for esophageal cancer was chosen because this type of cancer has been reported to have good affinity for FDG, and because esophageal cancer is a significant health risk which can be effectively treated with minimally-invasive techniques it is detected in early stages. Accumulation of FDG in the normal organs of the abdomen will be simulated by an anthropomorphic torso phantom filled with the appropriate amounts of FDG. The normal esophagus will be simulated by a flexible tube soaked in FDG. Esophageal lesions (both benign and malignant) will be simulated by thin disks of gelatin containing the appropriate amounts of FDG. The phantoms will be heated to simulated body temperature so that the effects of elevated ambient temperature on the operating characteristics of the detector unit can be assessed. A physician experienced in performing esophageal endoscopies will employ the Endoprobe system in examinations of the simulated esophagus. The results from these tests will be used to assess the effectiveness of the system and techniques for it use in detecting esophageal cancer, and evaluated the desirability of applying Endoprobe to other endoscopic procedures.