First demonstration of the FLASH effect with ultrahigh dose rate high-energy X-rays

Feng Gao; Yiwei Yang; Hongyu Zhu; Jianxin Wang; Dexin Xiao; Zheng Zhou; Tangzhi Dai; Yu Zhang; Gang Feng; Jie Li; Binwei Lin; Gang Xie; Qi Ke; Kui Zhou; Peng Li; Xuming Shen; Hanbin Wang; Longgang Yan; Chenglong Lao; Lijun Shan; Ming Li; Yanhua Lu; Menxue Chen; Song Feng; Jianheng Zhao; Dai Wu; Xiaobo Du

doi:10.1016/j.radonc.2021.11.004

First demonstration of the FLASH effect with ultrahigh dose rate high-energy X-rays

Radiother Oncol. 2022 Jan:166:44-50. doi: 10.1016/j.radonc.2021.11.004. Epub 2021 Nov 11.

Authors

Feng Gao¹, Yiwei Yang², Hongyu Zhu³, Jianxin Wang⁴, Dexin Xiao⁴, Zheng Zhou⁴, Tangzhi Dai¹, Yu Zhang¹, Gang Feng¹, Jie Li¹, Binwei Lin¹, Gang Xie⁵, Qi Ke⁵, Kui Zhou⁴, Peng Li⁴, Xuming Shen⁴, Hanbin Wang⁴, Longgang Yan⁴, Chenglong Lao⁴, Lijun Shan⁴, Ming Li⁴, Yanhua Lu⁴, Menxue Chen⁴, Song Feng⁶, Jianheng Zhao⁴, Dai Wu⁷, Xiaobo Du⁸

Affiliations

¹ Departmant of Oncology, Nuclear Medicine Laboratory of Mianyang Central Hospital, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China.
² Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, China.
³ Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China.
⁴ Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China.
⁵ Department of Pathology, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China.
⁶ School of Nuclear Science and Technology, University of South China, Hengyang, China.
⁷ Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China. Electronic address: wudai04@caep.cn.
⁸ Departmant of Oncology, Nuclear Medicine Laboratory of Mianyang Central Hospital, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China. Electronic address: duxiaobo2005@126.com.

PMID: 34774651
DOI: 10.1016/j.radonc.2021.11.004

Abstract

Purpose: This study aimed to evaluate whether high-energy X-rays (HEXs) of the PARTER (platform for advanced radiotherapy research) platform built on CTFEL (Chengdu THz Free Electron Laser facility) can produce ultrahigh dose rate (FLASH) X-rays and trigger the FLASH effect.

Materials and methods: EBT3 radiochromic film and fast current transformer (FCT) devices were used to measure absolute dose and pulsed beam current of HEXs. Subcutaneous tumor-bearing mice and healthy mice were treated with sham, FLASH, and conventional dose rate radiotherapy (CONV), respectively to observe the tumor control efficiency and normal tissue damage.

Results: The maximum dose rate of HEXs of PARTER was up to over 1000 Gy/s. Tumor-bearing mice experiment showed a good result on tumor control (p < 0.0001) and significant difference in survival curves (p < 0.005) among the three groups. In the thorax-irradiated healthy mice experiment, there was a significant difference (p = 0.038) in survival among the three groups, with the risk of death decreased by 81% in the FLASH group compared to that in the CONV group. The survival time of healthy mice irradiated in the abdomen in the FLASH group was undoubtedly higher (62.5% of mice were still alive when we stopped observation) than that in the CONV group (7 days).

Conclusion: This study confirmed that HEXs of the PARTER system can produce ultrahigh dose rate X-rays and trigger a FLASH effect, which provides a basis for future scientific research and clinical application of HEX in FLASH radiotherapy.

Keywords: Conventional dose rate radiotherapy; FLASH effect; FLASH radiotherapy; High-energy X-rays.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Clinical Protocols
Humans
Mice
Neoplasms*
Radiography
Radiotherapy Dosage
X-Rays