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: 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=760789
• 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，辐射剂量传递到肿瘤体积和关键结构可以幸免的程度的准确性直接关系到治疗结果。对患者的吸收剂量的不确定度由治疗设备的校准和剂量传递中的几个步骤引起的不确定度决定。这始于在临床参考校准条件下测定水中的吸收剂量(参考剂量法)。现代放射治疗提供技术的临床应用，如断层治疗、赛伯刀、磁共振图像引导辐射发生器(即MR-LINACS)、体积调制弧光治疗、扫描质子束放射治疗等，使用小范围、高剂量分数的辐射。因此，患者的治疗条件在物理上和剂量学上与标准参考校准条件相去甚远。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探测器技术，通过定义新的方法和通过为临床剂量学协议提供数据来减少这些不确定性。采用了两种主要的探测器方法，即量热法和切伦科夫辐射检测，主要有三个研究目标：(1)开发一种微型的“Aerrow”石墨探针量热仪，以解决临床小光子束和质子束的校准问题；(2)解决使用Aerrow进行千伏手术中辐射束的参考剂量测量中的不一致问题；(3)开发适用于现场临床剂量测量的Cherenkov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测量带来总体上更好的一致性、概念清晰度和更高的精度。从长远来看，提高准确性将带来更好的结果。我们的计划建立在实践改变剂量学成功的跟踪记录上，我们的一些技术可以提供给最终用户进行测试和实施。