Coded-aperture Compton scatter imaging for real-time tumor motion tracking during ablative radiotherapy

编码孔径康普顿散射成像用于消融放射治疗期间实时肿瘤运动跟踪

• 批准号: 10308727
• 负责人: Bernard L Jones
• 金额: $ 14.01万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-12-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10308727
• 关键词: Abdomen; Astronomy; Breathing; Clinical; Clinical Trials; Code; Compton radiation; Databases; Discipline of Nuclear Medicine; Dose; Dose-Limiting; Equipment; Future; Goals; Gold; Guidelines; Image; Implant; Linear Accelerator Radiotherapy Systems; Liver; Liver neoplasms; Local Therapy; Location; Magnetic Resonance Imaging; Measurement; Measures; Melanoma Cell; Methods; Modernization; Motion; Non-Small-Cell Lung Carcinoma; Normal tissue morphology; Pancreas; Pancreatic Adenocarcinoma; Patient-Focused Outcomes; Patients; Performance; Photons; Positioning Attribute; Radiation Dose Unit; Radiation Scattering; Radiation therapy; Renal Cell Carcinoma; Resolution; Roentgen Rays; Signal Transduction; Source; Syncope; System; Techniques; Testing; Therapeutic; Time; Toxic effect; Work; base; cost; design; detector; effective therapy; image guided; image guided radiation therapy; imager; imaging properties; imaging system; improved; improved outcome; lung cancer cell; novel; pancreatic neoplasm; pilot trial; programs; prototype; real-time images; side effect; tumor

Project Summary/Abstract Stereotactic Body Radiation Therapy (SBRT) is an aggressive, ablative local therapy that can be an effective treatment for many hard-to-treat tumors, such as pancreatic adenocarcinoma, non-small cell lung cancer, melanoma, and renal cell carcinoma. By delivering large, ablative doses of radiation in a small number of treatments, SBRT leads to significantly improved local control. However, there is a trade-off between delivering aggressive doses of radiation in the abdomen with SBRT and dose-limiting side-effects. A major problem is that the breathing-induced motion of the abdomen is erratic and unstable, rendering traditional methods of motion management ineffective. To enable safe and effective dose escalation for these tumors, we are proposing a novel imaging system that measures the position of fiducial markers implanted inside the patient. This system, called Coded Aperture Scatter Imaging (CASI), passively measures the position of tumors during treatment with no additional radiation dose. During radiotherapy, a beam of megavoltage x-rays is directed towards the tumor, and some of those photons undergo scattering interactions within the patient. These photons are more likely to interact in the dense, high-atomic-number fiducial markers, providing a differential signal that can be measured by an imager placed orthogonal to the beam. We propose to use coded aperture imaging to decode the location of these fiducial markers in real time. The coded aperture technique, utilized in fields such as astronomy and nuclear medicine, can help identify faint point sources within a broad background. CASI is clinically attractive for several reasons. This passive technique provides real-time motion information with no additional imaging dose, since it forms an image using scattered photons from the treatment beam. CASI is easily implementable on any existing clinical linear accelerator, since all modern linacs are equipped with a kV imaging panel placed orthogonal to the treatment beam. Fiducial markers are commonly implanted in these tumors, and the only additional hardware needed is the coded aperture itself, which can simply be placed between the patient and the detector. Finally, by measuring the motion of tumors during treatment one could increase the accuracy of treatment delivery, which could enable more effective, dose-escalated treatments that avoid toxicity to normal tissues. The goal of this work is to design, fabricate, and test an optimized aperture for CASI-guided radiotherapy.

项目总结/摘要 立体定向体部放射治疗（SBRT）是一种积极的、消融性局部治疗， 有效治疗许多难以治疗的肿瘤，如胰腺癌、非小细胞肺癌 癌症、黑素瘤和肾细胞癌。通过在一小部分人中释放大剂量的消融性辐射 SBRT的治疗，导致显着改善局部控制。然而，在以下方面存在权衡： 在腹部提供大剂量的辐射，具有SBRT和剂量限制性副作用。一个主要 问题是腹部的呼吸引起的运动是不稳定和不稳定的，使得传统的 运动管理方法无效。 为了使这些肿瘤安全有效的剂量递增，我们提出了一种新的成像系统， 它测量植入病人体内的基准标记的位置。这个系统叫做编码孔径 散射成像（CASI），在治疗期间被动测量肿瘤的位置，无需额外的 辐射剂量在放射治疗过程中，兆伏级X射线束被引导向肿瘤，并且一些X射线束被引导向肿瘤。 这些光子在患者体内经历散射相互作用。这些光子更有可能在 密集的、高原子序数的基准标记物，提供了可以由微处理器测量的差分信号， 成像器与光束正交放置。我们建议使用编码孔径成像解码的位置， 这些基准标记的真实的时间。编码孔径技术，用于天文学和 核医学，可以帮助识别微弱的点源在一个广泛的背景。 CASI在临床上具有吸引力有几个原因。这种被动技术提供了实时运动 这是因为它使用来自辐射源的散射光子形成图像， 治疗光束CASI可以在任何现有的临床直线加速器上轻松实现，因为所有现代 直线加速器配备有垂直于治疗射束放置的kV成像面板。基准标记被 通常植入这些肿瘤中，并且唯一需要的附加硬件是编码孔径本身， 其可以简单地放置在患者和检测器之间。最后，通过测量肿瘤的运动， 在治疗期间，可以提高治疗递送的准确性，这可以使得能够更有效， 避免对正常组织产生毒性的剂量递增治疗。这项工作的目标是设计，制造， 并测试CASI引导放射治疗的优化孔径。