Developments in radiotherapy physics for accurate, efficient and robust radiation measurements and dose calculations

放射治疗物理学的发展，实现准确、高效和稳健的辐射测量和剂量计算

• 批准号: RGPIN-2017-06253
• 负责人: Ali, Elsayed
• 金额: $ 3.06万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=762402
• 关键词: Developments; radiotherapy; physics; accurate; efficient

My research field is radiotherapy physics, a field devoted to the use of physics concepts to treat cancer and other diseases with radiation. My research program focuses on two strongly linked domains: radiation measurements, and radiation dose calculations in patients. The long-term vision of my research program is to seek greater understanding of the physics involved in these two domains, then translate this into novel and/or refined physics solutions that facilitate more accurate, efficient and robust radiation measurements and dose calculations. With that vision, the objectives that I am currently exploring are described below.The energy spectrum of the radiation generated by the treatment machine is important for dose calculations and for understanding radiation detectors. I have developed an accurate and practical device for these very challenging spectral measurements. My research group will use the device to explore long standing physics questions regarding the spectral differences among nominally identical (or matched) treatment machines. From this knowledge, we will improve dosimetric machine matching and develop dose calculation models that are robust against machine variations. The group will explore similar questions for other specialized treatment machines with unique characteristics. For radiation detector arrays, we will develop improved methods to make their characterization more accurate and robust.Most radiotherapy patients receive three types of scans: one to diagnose the disease, a special one for treatment planning and dose calculation, and one for positioning before treatment. This is inefficient for patients with urgent need for treatment. My research group is exploring an ambitious new paradigm to use diagnostic and/or positioning scans for treatment planning and dose calculation, eliminating the need for the middle scan. Numerous physics challenges exist in this paradigm, including scanner calibration, undesirable physics effects in scans, patient anatomy changes, disease visibility, and dose calculation accuracy. I am using my expertise to lead the development of physics solutions to these challenges using state-of-the-art radiation facilities, simulation methods, correction algorithms, and image deformation software.Radiation dose received by healthy organs such as the bowel is important for side effects and treatment outcomes. Accurate estimate of bowel dose is very challenging due to bowel mobility and ambiguity in scans, with limited success to date. My group is developing a physics platform that includes characterization of bowel daily changes, as well as a novel approach to automate bowel identification using its boundary organs. These are our building blocks towards accurate bowel dose estimates.The improved accuracy, efficiency and robustness in the areas above will lead to higher-quality, cost-effective radiotherapy.

我的研究领域是放射疗法物理学，该领域致力于使用物理学概念来治疗带有放射线的癌症和其他疾病。我的研究计划侧重于两个紧密联系的领域：辐射测量和患者的辐射剂量计算。我的研究计划的长期视觉是寻求对这两个领域涉及的物理学的更多了解，然后将其转化为新颖和/或精致的物理解决方案，以促进更准确，高效和稳健的辐射测量和剂量计算。有了这一视力，下面描述了我目前正在探索的目标。处理机产生的辐射的能量光谱对于剂量计算和理解辐射探测器很重要。我为这些非常具有挑战性的光谱测量开发了一种准确且实用的设备。我的研究小组将使用该设备探讨有关名义上相同（或匹配）治疗机之间光谱差异的长期物理问题。据此，我们将改善剂量计匹配并开发与机器变化相对于机器变化的剂量计算模型。该小组将为具有独特特征的其他专业治疗机探索类似的问题。对于辐射探测器阵列，我们将开发改进的方法以使其表征更加准确和稳健。大多数放射治疗患者接受了三种类型的扫描：一种用于诊断该疾病，一种用于治疗计划和剂量计算的特殊扫描，另一种用于治疗前的定位。这对于迫切需要治疗的患者效率低下。我的研究小组正在探索一种雄心勃勃的新范式，用于使用诊断和/或定位扫描进行治疗计划和剂量计算，从而消除了中间扫描的需求。该范式中存在许多物理挑战，包括扫描仪校准，扫描中不良物理效应，患者解剖学的变化，疾病可见性和剂量计算准确性。我正在利用我的专业知识来领导物理解决方案的开发，以使用最新的辐射设施，仿真方法，校正算法和图像变形软件来解决这些挑战。健康器官（例如肠）收到的放射剂量对于副作用和治疗结果很重要。由于肠道移动性和扫描中的歧义性，肠剂量的准确估计非常具有挑战性，迄今为止的成功有限。我的小组正在开发一个物理平台，其中包括对肠子每日变化的表征，以及一种使用其边界器官自动化肠识别的新方法。这些是我们朝着准确的肠量估计的基础。上述区域的准确性，效率和鲁棒性的提高将导致更高质量，具有成本效益的放射治疗。