Intraoperative Dose Visualization using X-Ray and Ultrasound for Prostate Brachyt

描述（申请人提供）：近距离放射治疗广泛应用于前列腺癌的治疗；在美国，每年有超过55000例手术。近距离放射治疗的流行是由于其微创性和适度的时间承诺的一部分病人。它的成功取决于适当的前列腺剂量，同时避免对邻近器官的过度辐射。尽管在技术上有了一些改进，一些中心发表了优秀的结果，但当代多中心报告和质量保证项目记录了结果的相当大的可变性，随之而来的是毒性和次优结果。众所周知，导致剂量学结果不佳的主要原因是辐射源定位错误、辐射源可视性差和前列腺水肿，这些因素综合起来会导致剂量过量和剂量不足。在手术过程中，对放射源动态可视化和术中剂量重建的迫切需要已得到广泛认可。术中剂量优化有望极大地改变近距离放射治疗的护理标准，使医生能够根据个体患者的解剖结构精确地调整剂量，并在手术完成前获得准确的剂量可视化和反馈。这需要术中植入物与前列腺和周围解剖结构的关系进行定位。我们建议开发一种临床可行的图像引导平台，该平台具有动态、精确和定量评估近距离治疗剂量的能力。这将允许对源位置改变进行持续纠正，并产生最佳植入物，从而降低毒性并改善癌症控制。目标1：动态剂量测定的发展：发展术中剂量测定和植入物优化的系统概念和算法。结果将是一个基于软件的，实用的方法，以实现真正的术中剂量可视化。该系统不需要对临床硬件进行重大更改，并且将对常规临床工作流程的改变降到最低，从而使其能够被广泛使用。目标2：系统实施和验证：将系统组件技术实施到适合临床使用的近距离放射治疗剂量测定套件中，并在术中对动态剂量测定系统进行评估。将对其在幻影中的技术准确性和稳健性进行完整的记录和验证，然后进行试点临床研究，以验证该系统并评估其性能和术中使用的适用性。这些信息将被输入Aim 3的系统更新中。目标3：临床假设和试验：利用单个系统组件进行irb批准的试验，以及对完全集成系统的最终研究，以便根据一组严格的基准建立性能，并与当前可用的标准方法进行比较。对结果的估计将在未来更大规模的II期研究中得到证实。

DESCRIPTION (provided by applicant): Brachytherapy is widely utilized in the management of prostate cancer; over 55,000 procedures are performed in the US annually. The prevalence of brachytherapy is due to its minimally invasive nature and modest time commitment on the part of the patient. Its success hinges on adequately dosing the prostate while avoiding excessive radiation to adjacent organs. Despite some improvements in technique and excellent published results from select centers, contemporary multi-center reports and quality assurance programs document considerable variability in results, with ensuing toxicity and suboptimal outcomes. Well-recognized major contributors to poor dosimetric results are source positioning errors, poor source visualization, and prostatic edema, which in aggregate lead to both regions of excessive as well as inadequate dose. The critical need for dynamic visualization of sources and intraoperative dose reconstruction during the procedure is broadly recognized. Intraoperative dose optimization promises to dramatically change the standard of care in brachytherapy by allowing the physician to precisely tailor the dose to the individual patient's anatomy, as well as obtain accurate dose visualization and feedback prior to procedure completion. This requires intra-operative localization of the implant in relation to the prostate and surrounding anatomy. We propose the development of a clinically feasible image-guidance platform with capability for dynamic, precise and quantitative evaluation of dose during brachytherapy. This will allow for ongoing correction for source position alterations and result in an optimal implant, leading to reduced toxicity and improved cancer control. Aim 1: Development of Dynamic Dosimetry: Develop a system concept and algorithms for intraoperative dosimetry and implant optimization. The result will be a software-based, practical method for true intra-operative dose visualization. The system will not require significant changes in clinical hardware and will minimally alter customary clinical workflow, making it feasible for translation into widespread use. Aim 2: System Implementation and Validation: Perform technical implementation of the system components into a brachytherapy dosimetry suite suitable for clinical use and evaluation of the dynamic dosimetry system intraoperatively. Full documentation and verification of its technical accuracy and robustness in phantoms will be conducted, followed by pilot clinical studies to validate the system and assess performance and suitability for intraoperative use. This information will be fed into system updates for Aim 3. Aim 3: Clinical Hypothesis and Trial: Perform IRB-approved trials utilizing individual system components, as well as a final study of the fully integrated system, in order to establish performance against a rigorous set of benchmarks and to compare with currently available standard methods. Estimates of outcomes will be obtained for confirmation in a future, larger Phase II study. PUBLIC HEALTH RELEVANCE: Prostate cancer is diagnosed in approximately 192,000 men per year in the United States, making it the most common cancer afflicting men and second most common in the overall population. Brachytherapy (implantation of radioactive seeds into the prostate) is widely used in the treatment of prostate cancer, yet studies show that it is common for men to receive suboptimal brachytherapy treatment, with doses either insufficient (leading to risk of cancer recurrence) or too high (leading to side effects and sometimes serious toxicity). A major contributor to these outcomes is the lack of existing techniques for physicians to visualize or 'see' radiation dose within the prostate as seeds are implanted; the goal of the proposed research is to develop a system which achieves this capability in a manner that can be readily implemented in operating rooms on a widespread scale nationwide.