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

超高剂量率放疗或FLASH-RT，已显示出在不影响肿瘤细胞杀伤的情况下大幅降低正常组织毒性的潜力。质子是目前唯一一种可以利用FLASH-RT治疗人体深部靶点的治疗方式。由于辐射剂量在不到一秒的时间内交付，因此需要超快速质量保证（QA）设备来验证FLASH-RT的交付。我们将开发一种多层条形离子室（MLSIC）装置，可以逐点测量质子闪光束的特性，包括点的位置和分布、能量和绝对剂量。该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flash-RT的QA设备的需求，我们将进行以下研究：1)在同步回旋加速器和等时回旋加速器中设计、优化和表征用于质子flash-RT QA的MLSIC设备；2) MLSIC质子束质量保证算法和软件的开发。

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.