Design of a real-time dosimetry prototype for use with external beam radiotherapy

描述（由申请人提供）：放射肿瘤患者接受高度复杂的治疗，如调强放射治疗（IMRT）、体积调弧治疗、立体定向放射外科手术和使用临床直线加速器的立体定向体部放射治疗。目前，放射治疗的质量保证（QA）是先验地测量累积剂量，这对时间射束调制不敏感。因此，所提供治疗的实际质量和安全性是未知的，并且无法识别或纠正患者的不当治疗。我们假设，如果在体内真实的时间在线传输探测器的外束放射治疗的发展，放射治疗事故将被防止，实现治疗精度，验证，记录和疗效的显着改善。该提议解决了对体内真实的时间传输探测器的迫切需要，以向放射肿瘤学诊所提供新的治疗验证和控制范例。这些在线、全时检测器将通过提高外部射束输送精度、提供真实的时间治疗验证、偏离计划治疗的真实的时间检测、自动射束停止和在检测到错误时发出警告、自动QA程序和标准化以及通过每个IMRT射束输送给患者的空间和时间通量的真实确定来提高治疗期间的患者安全性。这种增强的影响将提高外照射放射治疗的安全性和治疗准确性，这将改善50%癌症患者的治疗结果。仅在我们的诊所，这个数字估计是每天270名患者。在圣刘易斯的华盛顿大学和最佳医疗公司的联合会中，我们将利用高度集成的塑料封装的辐射硬化光纤和单片高增益光电传感器来开发用于外束放射治疗的在体真实的时间传输探测器。使用并行数据转换和并行数据采集集成电路构建检测器的高通量电子器件。这种快速且并行的电子接口能够在输送期间真实的检测治疗错误，并且如果患者健康受到损害，则相应地校正或暂停治疗。商业上可行的探测器原型将使用外部射束QA和拟人幻影进行验证，提供头颈癌和肺癌的治疗计划，并根据这两个癌症部位的真实的时间治疗验证制定患者QA协议。所提出的成像剂量计可以应用于其他癌症恶性肿瘤和治疗的真实的时间验证，但在本项目中，我们将集中在这两个网站作为模型和验证，为实施这项技术，以提高安全性和治疗效果的外部束放射治疗在目前的临床实践。所提出的技术的低成本和自主能力使其实现简单，适用于大型和小型临床手术。 公共卫生相关性：我们建议开发一种新型的体外射束放疗体内真实的时间传输探测器和软件工具，以促进体外射束强度调制治疗输送质量保证和患者安全的进步。我们的技术将首次允许在调强放射治疗过程中对输送给患者的真实注量进行体内和真实的时间测量。该技术基于耦合到单片光电传感器的低成本并行光纤阵列检测器，用于快速数据分析和处理的并行数据采集，以及用于治疗验证和患者安全的高速硬件实现算法。验证这项技术，以提高安全性和有效性的外部束治疗头颈部和肺癌将进行研究，以证明这项技术的实施，在今天的临床外部束兆伏放疗实践。

DESCRIPTION (provided by applicant): Radiation oncology patients receive highly complicated treatments such as intensity modulated radiation therapy (IMRT), volumetric modulated arc therapy, stereotactic radiosurgery and stereotactic body radiation therapy using clinical linear accelerators. Currently, the quality assurance (QA) of a radiation treatment is don a priori to measure cumulative doses, which is not sensitive to temporal beam modulation. Therefore, the actual quality and safety of the delivered treatment is unknown and patient mistreatment cannot be identified or corrected. We hypothesize that if in vivo real time on line transmission detectors for external beam radiotherapy are developed, radiotherapy accidents will be prevented to achieve considerable improvement in treatment accuracy, verification, recording, and efficacy. This proposal addresses the urgent need for in vivo real time transmission detectors to provide radiation oncology clinics a novel treatment verification and control paradigm. These online, all time detectors will increase patient safety during treatment by improving external beam delivery accuracy, providing real time treatment verification, real time detection of departures from planned treatments, automatic beam halting and warnings if errors are detected, automatic QA procedures and standardization, and true determination of the spatial and temporal fluence delivered to the patient by each IMRT beam. The impact of this enhancement will improve external beam radiotherapy safety and treatment accuracy, which will improve the treatment outcome for 50% of cancer patients. In our clinic alone, this number is estimated to be 270 patients per day. In a consortium between Washington University in Saint Louis and Best Medical Int., we will develop an in vivo real time transmission detector for external beam radiotherapy using highly integrated plastic encapsulated radiation hard scintillating fibers and monolithic high gain photosensors. The high throughput electronics of the detector are constructed using parallel data conversion and parallel data acquisition integrated circuits. This fast and parallel electronic interface is capable of detecting treatment errors durig delivery in real time and accordingly correct or suspend a treatment if patient health is compromised. The commercially viable detector prototype will be validated using external beam QA and anthropomorphic phantoms, delivering treatment plans for head and neck and lung cancer and formulating patient QA protocols based on real time treatment verification of these two cancer sites. The proposed imaging dosimeter can be applied to real time verification of other cancer malignancies and treatments, but in this project we will concentrate on these two sites as models and validation for the implementation of this technology to enhance the safety and therapeutic efficacy of external beam radiotherapy in current clinical practice. The low cost and autonomous capability of the proposed technology makes its implementation simple and adaptable for large and small clinical operations. PUBLIC HEALTH RELEVANCE: We propose the development of a novel in vivo real time transmission detector for external beam radiotherapy and software tools to foster the advancement of external beam intensity modulated treatment delivery quality assurance and patient safety. Our technology will allow, for the first time, the in vivo and real time measuremen of the true fluence delivered to a patient during intensity modulated radiotherapy treatment. The technology is based on low cost scintillating fiber array detectors coupled to monolithic photosensors, parallel data acquisition for fast data analysis and processing, and high speed hardware implemented algorithms for treatment verification and patient safety. Validation of this technology to enhance the safety and efficacy of external beam treatment of head and neck and lung cancer will be studied to demonstrate the implementation of this technology in today's clinical external beam megavoltage radiotherapy practice.