Development of Multilayer Strip Ion Chamber Device for the Measurement of Proton FLASH-Radiotherapy

超高剂量率放射治疗或FLASH-RT已显示出在不损害肿瘤细胞杀伤的情况下大幅降低正常组织毒性的潜力。质子是目前唯一能对人体深部靶点进行FLASH-RT治疗的方法。由于FLASH-RT的辐射剂量可在1秒内到达，因此需要一种超快速的质量保证（QA）装置来验证FLASH-RT的辐射剂量。我们将研制一种多层条形电离室（MLSIC）装置，该装置能逐点测量质子闪光束的特性，包括光斑位置和轮廓、能量、绝对剂量。MLSIC装置可用于质子闪光束的研制、调试和质量保证。为了开发MLSIC并满足用于flash-RT的QA设备的未满足的需求，我们将进行研究以实现以下目标：1）在同步回旋加速器和等离子体回旋加速器中设计、优化和表征用于质子FLASH-RT QA的MLSIC设备;以及2）开发用于MLSIC的质子束QA算法和软件。

Ultra-high dose rate radiotherapy or FLASH-RT, has shown the potential to drastically reduce the normal tissue toxicity without compromising tumor cell killing. Proton is the only treatment modality that can treat deep seated target in human body with FLASH-RT. With radiation dose delivered in less than a second, an ultra-fast quality assurance (QA) device is needed to verify the delivery of FLASH-RT. We will develop a multilayer strip ion chamber (MLSIC) device can measure the characteristics of a proton flash beam spot-by-spot including spot position and profile, energy, and absolute dose. The MLSIC device can be used for development, commissioning and QA of proton flash-beams. To develop the MLSIC and achieve the unmet need of QA device for flash-RT, we will perform the research studies to achieve following objectives: 1) Design, optimization, and characterization of a MLSIC device for proton FLASH-RT QA in a synchrocyclotron and an isochronous cyclotron; and 2) Development of proton beam QA algorithm and software for the MLSIC.