3-dimensional prompt gamma imaging for online proton beam dose verification

用于在线质子束剂量验证的 3 维瞬发伽马成像

• 批准号: 10635210
• 负责人: Jerimy C. Polf
• 金额: $ 57.57万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-15 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10635210
• 关键词: 3-Dimensional; Address; Anatomy; Award; Brain; Calibration; Cancer Patient; Cell Nucleus; Characteristics; Clinical; Collaborations; Computer software; Data; Deposition; Detection; Development; Dose; Ensure; Funding; Gamma Rays; Goals; Grant; Image; Industry; Inpatients; Lead; Legal patent; Location; Maps; Maryland; Measures; Methods; Monitor; Morphologic artifacts; Normal tissue morphology; Patients; Pelvis; Photons; Pilot Projects; Procedures; Process; Prostate Cancer therapy; Proton Radiation; Protons; Publications; Radiation; Radiation therapy; Rectum; Research; Signal Transduction; System; Techniques; Three-Dimensional Image; Tissues; Toxic effect; Translating; Translations; Treatment Efficacy; Uncertainty; United States National Institutes of Health; Work; clinical translation; computerized data processing; image guided; image processing; image reconstruction; imaging modality; imaging system; improved; in vivo; in vivo imaging system; industry partner; innovation; novel; prevent; prostate radiotherapy; proton beam; prototype; quality assurance; rapid growth; rectal; simulation; success; therapy development; tumor

ABSTRACT: This proposal aims to address the long-term challenge of range uncertainties in proton radiotherapy (RT) by developing a novel 3D prompt gamma imaging (PGI) system for in vivo dose verification. Proton RT can potentially achieve better normal tissue sparing than photon RT due to proton beams’ finite range and Bragg peak (BP) in dose deposition. The number of proton centers in the US has increased by over 40% in the past 4 years. However, despite the promise and rapid growth of proton RT, its treatment efficacy is severely limited by uncertainties in the proton beam range (i.e., the precise location of BP in the patient) arising from daily patient setup errors, anatomic change, and dose calculation uncertainties. To account for this, larger-than-desirable treatment margins (potentially>1cm) are added around the tumor in practice to ensure adequate dose coverage. These margins significantly increase the dose to adjacent healthy tissues, leading to an increase in radiation-induced toxicities. Concerns of increased toxicities, in turn, constrain the dose that can be prescribed to the tumor and thus limit the tumor control we can achieve. Therefore, there is a significant and critical need to overcome beam range uncertainties so that the true potential of proton RT can be fully exploited. PGI has become a promising technique to verify and minimize range uncertainties by imaging the prompt gamma (PG) signals emitted from the non-elastic proton-nucleus interactions during proton RT. In our prior NIH-funded research, we developed a prototype PGI system that demonstrated the world's first 3D images of PG emission from clinical proton beams with a range shift detection accuracy of ~3 mm. Despite the early success, our system had several critical barriers that prevented it from being translated, including limited count rate of the Compton camera, crude PG image quality with artifacts and severe distortion due to parallax, and lack of dose estimation. In this grant, we will revamp the entire system with both hardware and software innovations to overcome current barriers to achieve high precision 3D dose verification. The following aims will be pursued: (1) develop, integrate and synchronize a quad-camera PGI system into the proton RT machine, (2) develop novel image processing and reconstruction methods to achieve high-precision 3D dose verification, and (3) perform a pilot patient study to evaluate its clinical impact. We have formed a top-tier academic (Maryland) and industry (Varian) partnership with complementary expertise and a track record of collaboration to ensure the success of the project. Our collaborative development and translation of the PGI system will be a major step toward fulfilling our long-term goal of improving the efficacy of proton RT by minimizing its range uncertainties. Our PGI system will be the first to provide truly 3D online dose verification during proton treatment delivery, which can lead to a paradigm shift toward high-precision proton RT. This breakthrough will unleash the full potential of proton RT to use minimal treatment margin to achieve optimal tumor control with reduced toxicities for the growing number of cancer patients treated by proton RT in the US and worldwide.

摘要：该提案旨在解决质子范围不确定性的长期挑战 通过开发用于体内剂量验证的新型 3D 即时伽马成像 (PGI) 系统来进行放射治疗 (RT)。 由于质子束的有限性，质子放疗可能比光子放疗实现更好的正常组织保护 剂量沉积的范围和布拉格峰（BP）美国的质子中心数量增加了超过。 过去 4 年增长了 40% 然而，尽管质子放疗前景广阔且增长迅速，但其治疗效果却很差。 受到质子束范围（即患者血压的精确位置）不确定性的严重限制 来自日常患者设置错误、解剖变化和剂量不确定性计算。 在实践中，在肿瘤周围添加大于所需的治疗边缘（可能>1cm），以确保 足够的剂量覆盖范围显着增加了邻近健康组织的剂量，从而导致 对辐射引起的毒性增加的担忧反过来又限制了可能的剂量。 因此，对肿瘤进行处方，从而限制了我们可以实现的肿瘤控制。 迫切需要克服射束范围的不确定性，以便充分发挥质子 RT 的真正潜力 PGI 已成为一种通过成像来验证和最小化范围不确定性的有前途的技术。 在我们的质子 RT 过程中，非弹性质子-核相互作用发出瞬发伽马 (PG) 信号。 在 NIH 资助的研究之前，我们开发了一个原型 PGI 系统，展示了世界上第一个 3D 临床质子束的 PG 发射图像，距离偏移检测精度为 ~3 mm。 早期的成功，我们的系统有几个关键障碍阻碍了它的翻译，包括有限的 康普顿相机的计数率，粗糙的 PG 图像质量，由于视差而存在伪影和严重失真， 以及缺乏剂量估计 在这笔拨款中，我们将通过硬件和软件改造整个系统。 克服当前障碍以实现高精度 3D 剂量验证的创新将实现以下目标。 追求：（1）开发、集成并同步四相机PGI系统到质子RT机器中， (2) 开发新颖的图像处理和重建方法以实现高精度3D剂量验证， (3) 进行一项试点患者研究以评估其临床影响。我们已经组建了顶级学术机构。 （马里兰州）和行业（瓦里安）的伙伴关系，具有互补的专业知识和良好的合作记录 为了确保该项目的成功，我们将共同开发和翻译 PGI 系统。 朝着实现通过最小化质子放疗范围来提高质子放疗功效的长期目标迈出的重要一步 我们的 PGI 系统将是第一个在质子期间提供真正的 3D 在线剂量验证的系统。 治疗交付，这可能会导致向高精度质子 RT 的范式转变。 充分发挥质子放疗的潜力，以最小的治疗裕度实现最佳的肿瘤控制 在美国和世界范围内，越来越多接受质子放疗的癌症患者的毒性降低。