Abstract
As an advanced treatment method in the past five years, ultra-high dose rate (FLASH) radiotherapy as a breakthrough and milestone in radiotherapy development has been verified to be much less harmful to healthy tissues in different experiments. FLASH treatments require an instantaneous dose rate as high as hundreds of grays per second to complete the treatment in less than 100 ms. Current proton therapy facilities with the spread-out of the Bragg peak formed by different energy layers, to our knowledge, cannot easily achieve an adequate dose rate for FLASH treatments because the energy layer switch or gantry rotation of current facilities requires a few seconds, which is relatively long. A new design for a therapy facility based on a proton linear accelerator (linac) for FLASH treatment is proposed herein. It is designed under two criteria: no mechanical motion and no magnetic field variation. The new therapy facility can achieve an ultra-high dose rate of up to 300 Gy/s; however, it delivers an instantaneous dose of 30 Gy within 100 ms to complete a typical FLASH treatment. The design includes a compact proton linac with permanent magnets, a fast beam kicker in both azimuth and elevation angles, a fixed gantry with a static superconducting coil to steer proton bunches with all energy, a fast beam scanner using radio-frequency (RF) deflectors, and a fast low-level RF system. All relevant principles and conceptual proposals are presented herein.
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All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Wen-Cheng Fang, **ao-**a Huang, Jian-Hao Tan and Yi-**ng Lu. The first draft of the manuscript was written by Wen-Cheng Fang, and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.
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This work was supported by the Alliance of International Science Organizations (No. ANSO-CR-KP-2020-16) and the National Key R&D Program of China (No. 2018YFF0109203).
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Fang, WC., Huang, XX., Tan, JH. et al. Proton linac-based therapy facility for ultra-high dose rate (FLASH) treatment. NUCL SCI TECH 32, 34 (2021). https://doi.org/10.1007/s41365-021-00872-4
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DOI: https://doi.org/10.1007/s41365-021-00872-4