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

超高剂量率放射治疗或闪光放射治疗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。质子治疗是目前唯一一种可以通过闪光放射治疗人体深层靶点的治疗手段。由于辐射剂量在不到一秒的时间内传递，需要一个超快质量保证(QA)设备来验证Flash-RT的传递。我们将开发一种多层带状电离室(MLSIC)装置，可以逐点测量质子闪光束流的特性，包括光斑位置和轮廓、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和实现闪光RT质检装置的未得到满足的需求，我们将开展以下研究工作：1)同步回旋加速器和等时回旋加速器质子闪光RT质检装置的设计、优化和表征；2)MLSIC质子束QA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.