Real-time in vivo proton range verification in proton therapy with thallium bromide detectors

使用溴化铊探测器进行质子治疗中的实时体内质子范围验证

• 批准号: 10559516
• 负责人: Gerard Ariño Estrada
• 金额: $ 68.26万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-15 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10559516
• 关键词: 3-Dimensional; Acceleration; Address; Anodes; Biomedical Engineering; Body Regions; Bromides; Calibration; Cancerous; Charge; Clinical; Collimator; Cyclotrons; Data Set; Dedications; Deposition; Detection; Devices; Digital Signal Processing; Dimensions; Dose; Electrodes; Electrons; Face; Film; Gamma Rays; Goals; Head and Neck Cancer; Head and neck structure; Health Services Accessibility; Healthcare; Heterogeneity; Image; Institution; Laboratories; Length; Letters; Light; Liver; Location; Lung; Methods; Modeling; Monitor; Motion; Nature; Nuclear; Operative Surgical Procedures; Organ; Outcome; Parents; Patients; Performance; Photons; Positioning Attribute; Protons; Radiation; Radiation Dose Unit; Radiation therapy; Radioactive; Research Project Grants; Resolution; Risk; Scanning; Semiconductors; Silicon; Source; Spectrum Analysis; Surface; Techniques; Testing; Thallium; Time; Tissues; Toxic effect; Treatment Efficacy; Treatment Protocols; Uncertainty; Work; X-Ray Computed Tomography; attenuation; beamline; cancer therapy; conventional therapy; density; detection platform; detector; falls; feasibility testing; improved; in vivo; instrumentation; manufacture; nanosecond; novel; operation; particle; photomultiplier; photonics; preservation; printed circuit board; proton beam; proton therapy; prototype; real time monitoring; respiratory; response; seal; signal processing; tumor

Summary Radiotherapy using protons is an attractive option as it has the potential to better preserve healthy tissue compared to radiation with photons or electrons, and because trial outcomes indicate it can replace surgery for radical cancer treatments as well. Proton therapy makes use of the finite range of heavy charged particles with an intensity maximum at the end of their path (Bragg peak) followed by a sharp fall-off of the dose. However, predicting the proton range based on computed tomography (CT) scans carries an estimation uncertainty. For treatments with proximal critical organs and limited accessibility (head and neck), high heterogeneities (lung), or significant breath motion (liver) such uncertainty is too high and the therapy is in the best case challenging, if not impossible. New instrumentation is needed to monitor the location of the Bragg peak to 1-2 mm accuracy within several seconds in these challenging scenarios. We propose to use the novel Cerenkov Charge Induction (CCI) thallium bromide (TlBr) detectors for proton range verification (PRV) in proton therapy. CCI TlBr detectors combine the detection of Cerenkov light, which provides sub-nanosecond timing resolution with the conventional readout of semiconductor detectors, which provides excellent energy resolution and 3-D segmentation. Moreover, TlBr has a shorter attenuation length than most commonly used scintillation materials for prompt-gammas up to 6.1 MeV. CCI TlBr detectors provide a unique performance, as they offer simultaneous excellent performance in energy, time, and spatial resolution, that fits the needs of PRV in proton therapy. In this project, we will test the feasibility of using a non-collimated prompt gamma timing – Compton camera (PGT-CC) camera based on pixel CCI TlBr detectors for PRV in proton therapy. We will 1) manufacture pixel CCI TlBr detectors with optimized surface treatment to couple the photodetector and with highly-stable long- lasting electrodes; 2) characterize the detector features of pixel CCI TlBr devices in a benchtop setting using sealed sources, including energy, spatial, and timing resolution; 3) evaluate the performance of a PGT-CC camera for PRV made with pixel CCI TlBr detectors in a beamline with protons accelerated to 67.5 MeV; and 4) compare the performance of our PGT-CC camera prototype with gold standard techniques following realistic treatment protocols at a clinical beamline with protons accelerated to >200 MeV. The accomplishment of the aims of this project will determine the potential of CCI TlBr detectors to become the most competitive devices for PRV in proton therapy. A successful performance of the proposed detection system would allow to exploit the benefits of proton therapy in treatment regions that are currently very challenging, leading to increased treatment efficacy and lower toxicity in the healthy organs of the patients.

概括 使用质子的放射治疗是一种有吸引力的选择，因为它有可能更好地保存健康组织 与光子或电子辐射相比，并且因为试验结果表明它可以取代手术 以及根治性癌症治疗。质子疗法利用有限范围的重带电粒子 在其路径末端（布拉格峰）出现强度最大，随后剂量急剧下降。然而， 根据计算机断层扫描 (CT) 扫描预测质子范围存在估计不确定性。为了 近端关键器官的治疗和可及性有限（头部和颈部），高度异质性（肺）， 或显着的呼吸运动（肝脏），这种不确定性太高，并且在最好的情况下治疗具有挑战性，如果 并非不可能。需要新的仪器来监测布拉格峰的位置，精度为 1-2 毫米 在这些具有挑战性的场景中几秒钟内。 我们建议使用新型切伦科夫电荷感应 (CCI) 溴化铊 (TlBr) 质子探测器 质子治疗中的范围验证（PRV）。 CCI TlBr 探测器结合了切伦科夫光的检测， 通过半导体探测器的传统读出提供亚纳秒定时分辨率， 提供出色的能量分辨率和 3D 分割。此外，TlBr 的衰减长度较短 比最常用的瞬发伽马闪烁材料高达 6.1 MeV。 CCI TlBr 探测器提供 独特的性能，因为它们在能量、时间和空间上同时提供出色的性能 分辨率，符合质子治疗中PRV的需要。 在这个项目中，我们将测试使用非准直瞬发伽玛定时——康普顿相机的可行性 (PGT-CC) 相机基于像素 CCI TlBr 探测器，用于质子治疗中的 PRV。我们将1）制造像素 CCI TlBr 探测器经过优化的表面处理以耦合光电探测器并具有高度稳定的长寿命 持久电极； 2) 在台式设置中表征像素 CCI TlBr 器件的探测器特征 密封源，包括能量、空间和时间分辨率； 3) 评估PGT-CC的性能 PRV 相机由质子加速至 67.5 MeV 的束线中的像素 CCI TlBr 探测器制成；和 4) 将我们的 PGT-CC 相机原型的性能与遵循现实的黄金标准技术进行比较 质子加速至 >200 MeV 的临床光束线治疗方案。 该项目目标的实现将决定 CCI TlBr 探测器成为 质子治疗中最具竞争力的 PRV 设备。所提出的检测的成功执行 系统将允许在目前非常严重的治疗区域利用质子治疗的好处 具有挑战性，从而提高治疗效果并降低患者健康器官的毒性。