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，对肿瘤体积的放射剂量递送的准确性和关键结构可以被保留的水平与治疗结果直接相关。患者吸收剂量的不确定性由治疗设备校准和剂量输送中的几个步骤产生的不确定性确定。首先是在临床参考校准条件下测定水中的吸收剂量（参考剂量测定）。现代放射治疗输送技术的临床应用，例如断层治疗、射波刀、磁共振图像引导放射发生器（即，MR-Linacs）、体积调制弧治疗、扫描质子束放射治疗等使用高剂量分数的小射野递送放射。因此，患者治疗条件在物理上和剂量学上与标准参考校准条件相差甚远。这导致了辐射输送的不确定性。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，定义新的方法并为临床剂量测定方案提供数据来减少这些不确定性。在三个主要研究目标中采用了两种主要的探测器方法，量热法和切伦科夫辐射探测：（1）开发微型“Aerrow”石墨探针量热计，以解决临床小光子束和质子束的校准问题;（2）解决使用Aerrow的kV术中辐射束的参考剂量测定中的不一致问题;（3）发展一种适合于现场临床剂量测量的切连科夫辐射剂量计技术。该计划的影响是为小型和非标准射束的剂量测定带来总体上更好的一致性、概念清晰度和更高的准确性。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测定成功的跟踪记录上，我们的一些技术可供最终用户测试和实施。