Advanced Accurate Dosimetry in Radiation Therapy using Calorimetric and Cherenkov Techniques

使用量热和切伦科夫技术在放射治疗中进行先进的精确剂量测定

• 批准号: RGPIN-2019-06746
• 负责人: Seuntjens, Jan
• 金额: $ 6.92万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=716076
• 关键词: Advanced; Accurate; Dosimetry; Radiation; Therapy

In radiation therapy the accuracy of radiation dose delivery to the tumour volume and the level to which critical structures can be spared is directly correlated to treatment outcomes. The uncertainty of the absorbed dose to the patient is determined by uncertainties resulting from several steps in the treatment devices' calibration and the dose delivery. This starts with the determination of absorbed dose in water in clinical reference calibration conditions (reference dosimetry). Clinical application of modern radiation therapy delivery technology, such as TomoTherapy, Cyberknife, magnetic resonance image-guided radiation generators (i.e., MR-Linacs), volumetric modulated arc therapy, scanned proton beam radiation therapy, etc deliver radiation using small fields in high-dose fractions. Hence, the patient treatment conditions are physically and dosimetrically far removed from the standard reference calibration conditions. This has led to uncertainties in radiation delivery. Our NSERC discovery grant program aims to reduce these uncertainties by creating and developing new-generation clinically viable detector technologies, by defining new methodologies and by providing data for clinical dosimetry protocols. Two main detector methodologies are pursued, calorimetry and Cherenkov radiation detection in three main research objectives: (1) to develop a miniature `Aerrow' graphite probe calorimeter to address calibration of clinical small photon beams and proton beams; (2) to address inconsistencies in the reference dosimetry of kV intraoperative radiation beams using the Aerrow; (3) to develop a Cherenkov-radiation dosimeter technique suitable for in-situ clinical dosimetry. The impact of this program is to bring overall better consistency, conceptual clarity and improved accuracy to the dosimetry of small and nonstandard beams. Improved accuracy in the long term will lead to better outcomes. Our program builds on a track record of practice-changing dosimetry successes with some of our technologies to become available to end-users for testing and implementation.

在放射治疗中，放射剂量对肿瘤体积的准确性和关键结构可以保留的水平与治疗结果直接相关。患者吸收剂量的不确定度是由治疗装置校准和给药过程中几个步骤产生的不确定度决定的。首先是在临床参考校准条件下测定水中的吸收剂量（参考剂量学）。现代放射治疗传递技术的临床应用，如TomoTherapy、射波刀、磁共振成像引导辐射发生器（即MR-Linacs）、体积调制电弧治疗、扫描质子束放射治疗等，以小场高剂量分量传递辐射。因此，患者的治疗条件在物理和剂量学上与标准参考校准条件相距甚远。这导致了辐射传递的不确定性。我们的NSERC发现资助计划旨在通过创建和开发新一代临床可行的检测器技术，通过定义新的方法和通过为临床剂量测定方案提供数据来减少这些不确定性。本文主要研究了量热法和切伦科夫辐射检测两种主要的探测器方法：①研制微型Aerrow石墨探针量热计，用于临床小光子束和质子束的校准；(2)使用Aerrow解决kV术中放射束参考剂量测定的不一致性；(3)研制适合临床现场剂量测定的切伦科夫辐射剂量计技术。该计划的影响是为小型和非标准光束的剂量学带来更好的一致性、概念清晰度和更高的准确性。从长远来看，准确性的提高将带来更好的结果。我们的项目建立在改变剂量学实践的成功记录的基础上，我们的一些技术可以为最终用户提供测试和实施。