Gated Optical DetectorsDose Guided Radiotherapy

一家小型电子原型企业已同意协助开发第二代探测器接口。由于光子计数模块的高压电路出现问题，该设备计划于2010年9月中旬交付。它将是一个具有4个检测通道的自选通系统，所有信号处理将完全通过硬件执行。此外，NRL正在开发新的光纤，这种光纤的剂量响应将更加均匀，将基于100微米的光纤，而不是目前的400微米模型。最终的系统将作为辐射剂量测量系统进行验证，并将用于非常规临床和研究测量，包括兆伏和千伏X射线和电子束的小场和微场剂量测量。电子剂量计的原型已经交付。初步实验已经检测到测量集合之间的微小校准漂移。目前，测量不确定度为+/-4%。若能消除这一变动，将降至+/-0.5%。我们目前正在与该公司合作，以确定不确定性的来源并加以纠正。一旦这项工作完成，我们将全面认证该系统的临床测量。此外，对软件的修改将允许设备在连续采集和脉冲模式下运行。这将允许使用能量较低的X射线能量(正电压X射线和大多数近距离治疗源)进行剂量测定。

A small electronics prototyping business has agreed to assist in the development of a second generation detector interface. Delivery of this device is scheduled for mid-September, 2010 due to problems with the high voltage circuits of the photon counting modules. It will be a self-gated system with 4 detection channels and all signal processing will be performed completely via hardware. Additionally, new fibers are being developed by NRL that will be more uniform in dose response and will be based on a 100 micron optical fiber rather than the current 400 micron model. The resulting system will undergo validation as a radiation dosimetry system and will be employed for non-routine clinical and research measurements involving small field and micro-field dosimetry for both megavoltage and kilovoltage x-ray and electron beams. The prototype dosimeter electronics have been delivered. Preliminary experiments have detected small calibration shifts between measurement sets. Currently the measurement uncertainty is +/-4%. If the shift can be eliminated, it will reduce to +/-0.5%. We are currently working with the company to determine the source of the uncertainty and to correct it. Once this is completed, we will fully certify the system for clinical measurements. Additionally, modification to the software will permit operation of the device in continuous acquisition as well as pulsed mode. This will permit use of the device for dosimetry with lower energy x-ray energies (orthovoltage x-rays and most brachytherapy sources).