Devices and methods to directly measure absolute absorbed dose to water in non-standard complex beams in a radiotherapy clinical setting

在放射治疗临床环境中直接测量非标准复杂射束中水的绝对吸收剂量的装置和方法

• 批准号: RGPIN-2022-04311
• 负责人: Sarfehnia, Arman
• 金额: $ 2.48万
• 依托单位: University of Toronto
• 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=764437
• 关键词: Devices; methods; directly; measure; absolute

The goal of radiation therapy is to use radiation to damage tumor cells to an extent that they are either dead (necrotic), or not viable to reproduce (sterile). The treatment outcome is directly correlated with the accuracy of radiation dose delivery which itself is comprised of several steps starting from radiation delivery system calibration all the way to dose delivery. Current dosimetry protocols require a so-called `reference' conditions for calibration which traditionally has been a good reflection of radiotherapy delivery setup. However, with more recent novel developments in radiotherapy delivery technology (e.g. MR-linac, Tomotherapy, CyberKnife, Volumetric Modulated Arc Therapy (VMAT), scanned proton beams, etc.), there has been a general shift from low dose / low dose rate radiation fractions delivered using large static field sizes, to delivery of high dose fractions using small, highly modulated, complex fields dynamically delivered at relatively high dose rates. As such, the patient treatment conditions (and RT delivery units) are becoming far removed from reference calibration conditions. This has led to added uncertainties, or worst errors in dosimetry. The goal of our NSERC discovery grant is to reduce radiation dosimetry uncertainty and drastically decrease possibility of user error by innovating and developing new generation of detectors in radiation therapy or modification of current detectors and detection techniques for dose measurement in highly complex radiation delivery modalities. To that end, the main objectives of the research are: 1) To develop a new 3-D printed, portable and fully image-able water calorimeter appropriate for everyday clinical use; 2) to use the proposed absolute dosimeter in (1) to not only show feasibility of absolute dose measurement in a safe and accurate way in clinic, but to also determine correction factors for traditional detectors that will be essential to future dosimetry protocols in many of these new and complex delivery technologies. Building on our previous practice-changing dosimetry success of bringing new dosimeter technologies to market and contributing to the development of new protocols in modern RT, our research program will have strong positive impact on overall improvement of radiation dose uncertainty and reducing operator error in small and non-standard radiation dosimetry.

放射治疗的目的是使用放射线来破坏肿瘤细胞，使其死亡（坏死）或无法繁殖（无菌）。治疗结果与辐射剂量输送的准确性直接相关，辐射剂量输送本身包括从辐射输送系统校准一直到剂量输送的几个步骤。目前的剂量测定方案需要所谓的“参考”校准条件，这在传统上是放射治疗输送设置的良好反映。然而，随着放射治疗输送技术（例如，MR直线加速器、断层治疗、射波刀、体积调制弧治疗（VMAT）、扫描质子束等）的更近期的新发展，已经从使用大的静态场尺寸递送的低剂量/低剂量率辐射部分向使用以相对高的剂量率动态递送的小的、高度调制的、复杂的场递送高剂量部分的一般转变。因此，患者治疗条件（和RT输送装置）与参考校准条件相距甚远。这导致了剂量测定中的不确定性或最严重的误差。 我们的NSERC发现补助金的目标是通过创新和开发新一代放射治疗探测器或修改当前探测器和探测技术来降低辐射剂量测定的不确定性，并大幅降低用户错误的可能性，以用于高度复杂的辐射输送模式中的剂量测量。为此，该研究的主要目标是：1）开发一种适合日常临床使用的新型3D打印，便携式和完全可成像的水热量计; 2）使用在（1）中提出的绝对剂量计，不仅表明在临床中以安全和准确的方式进行绝对剂量测量的可行性，而且还确定传统探测器的校正因子，这些校正因子对于许多这些新的和复杂的递送技术中的未来剂量测定方案将是必不可少的。基于我们以前的实践改变剂量学的成功，将新的剂量计技术推向市场，并为现代RT新协议的发展做出贡献，我们的研究计划将对辐射剂量不确定性的整体改善和减少操作员错误产生强烈的积极影响。