Clinical Radiation Physics Service

我们有一系列的举措，利用我们的高剂量率远程后装机（HDR），使用一个小的，高强度的192 Ir源间质和腔内近距离治疗。该部门目前拥有两台最先进的Varian TrueBeam STX加速器，配备120叶高清晰度多叶准直器，叶片宽度为2.5 mm。这使得它们能够执行无框架立体定向放射外科手术（SRS），尽管采集中包含一组直径范围为4 mm至25 mm的圆形准直器和SRS计划模块。除了传统的纵向、横向和垂直位置调整之外，患者治疗床还提供6自由度（6DOF），通过允许俯仰、滚动和偏航校正来大大提高位置精度。这两种加速器的治疗输送参数匹配在0.5%以内，从而提供真正的冗余，确保患者可以根据其分次时间表继续接受治疗。这些机器包括Edge Extracranial SABR Package，允许他们使用基于射频局部定位的高级运动管理（使用植入的基准应答器和红外摄像机）提供无框架立体定向体部放射治疗（SBRT）。修改后的边缘包包括一个Calypso射频定位系统，利用植入式基准传感器和实时跟踪能力。实时光学跟踪利用升级的光学表面监测系统（VisionRT）系统来监测身体表面，并在表面变形（由于运动）时中断治疗，以及使用Calypso RF应答器监测前列腺位置并相应地门控治疗输送的前列腺放射治疗方案的临床实施。ROB已经购买了一台新的Elekta Flexitron 40通道高剂量率（HDR）远程近距离放射治疗后装机，以取代其以前的设备。此外，ROB还获得了一个新的B-K超声单元，相对于以前的单元，它大大提高了成像能力。我们已经获得了一个治疗床安装步进稳定器，以改善针插入方法，并正在努力适应机动扫描系统的探头，以加快图像采集。ROB有一个专用的近距离放射治疗套件（B2-3643）。这间手术室现已投入临床使用，并已证明在手术和辅助设备的布局方面提供了更大的灵活性，这反映在减少了病人的麻醉时间上。ROB安装了一个替代CT模拟器。虽然整体上与现有设备相似，但新系统具有更强大的处理能力，可加速图像重建。它还利用双能量、连续CT扫描，可以进行后处理，以增强对碘、钙或其他可检测元素的检测，这些元素用作肿瘤功能成像的生物示踪剂。ROB已完成向ARIA-RO版本16的过渡。现在，它利用了NIH活动目录系统，该系统提高了安全性，并利用虚拟服务器环境提高了操作可靠性。最后，ROB已经转移到一个新的IT骨干，简化了Eclipse工作站和TrueBeam加速器之间的通信在贝塞斯达校园和虚拟服务器农场位于NCI阴影格罗夫数据中心。这提供了稳定的通信。ROB还升级了其机械车间，以符合当前的电气标准，并允许安装更先进的制造设备，如3D打印机和水刀切割机，以更好地支持临床研究项目。

We have a series of initiatives utilizing our High Dose-Rate Remote Afterloader (HDR) using a small, high intensity 192Ir source for interstitial and intercavitary brachytherapy. The department now has two state-of-the-art Varian TrueBeam STX accelerators which are equipped with 120 leaf high definition multi-leaf collimators with leaf widths as thin as 2.5 mm. This renders them capable of performing frameless stereotactic radiosurgery (SRS), although a set of circular collimators with diameters ranging from 4mm to 25mm and an SRS planning module are included in the acquisition. The patient couches also provide for 6 Degrees-of-Freedom (6DOF) to greatly improve positional accuracy by permitting corrections for pitch, roll and yaw, in addition to the traditional longitudinal, lateral and vertical position adjustments. The treatment delivery parameters of these two accelerators are matched to within 0.5%, thus providing true redundancy, assuring that patients can continue to receive their treatments according to their fractionation schedule. These machines include the Edge Extracranial SABR Package that will permit them to deliver frameless stereotactic body radiation therapy (SBRT) using advanced motion management based on radiofrequency local positioning using implanted fiducial transponders and infrared cameras. The revised Edge package includes a Calypso radiofrequency positioning system, utilizing implantable fiducial transducers and real-time tracking capability. The real-time optical tracking utilizes an upgraded Optical Surface Monitoring System (VisionRT) system to monitor the body surface and to interrupt the treatment if the surface distorts (due to motion) and the clinical implementation of a prostate radiotherapy protocol using Calypso RF transponders to monitor prostate position and correspondingly gate the treatment delivery. ROB has acquired a new Elekta Flexitron 40 channel High-Dose-Rate (HDR) remote brachytherapy afterloader to replace its previous unit. Additionally, ROB has acquired a new B-K ultrasound unit, which has vastly improved imaging capabilities relative to the previous unit. We have acquired a couch-mounted stepper-stabilizer to improve needle insertion methodology and are working on adapting a motorized scanning system for the probe to speed image acquisition. ROB has a dedicated brachytherapy suite (B2-3643). This room is now clinically operational and has proved to provide greater flexibility in the layout of operative and support equipment, which is reflected in reduced patient time under anesthesia. ROB has installed a replacement CT Simulator. While similar overall to the existing unit, the new system has substantially more powerful processing power to accelerate image reconstruction. It also utilizes dual energy, sequential CT scans, which can be post processed to enhance the detection of Iodine, Calcium or other detectable elements utilized as bio-tracers for the functional imaging of tumors. ROB has completed its transition to ARIA-RO version 16. This now utilizes the NIH Active Directory system, which improves security, and utilizes a virtual server environment to enhance operational reliability. Finally, ROB has shifted to a new IT backbone, streamlining communication between the Eclipse workstations and TrueBeam accelerators at the Bethesda campus and the virtual server farm located at the NCI Shady Grove Data center. This provides for stable communications. ROB has also upgraded its Machine Shop to conform with current electrical standards as well as permitting the installation of more advanced fabrication equipment, such as a 3-D printer and a water jet cutter, in order to better support clinical research projects.