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

Gao, F.; Yang, Y.; Zhu, H.; Wang, J.; Xiao, D.; Zhou, Z.; Dai, T.; Zhang, Y.; Feng, G.; Li, J.; Lin, B.; Xie, G.; Ke, Q.; Li, P.; Sheng, X.; Wang, H.; Yan, L.; Lao, C.; Li, M.; Lu, Y.; Zhao, J.; Feng, S.; Du, X.; Wu, D.

doi:10.1101/2020.11.27.401869

bioRxiv · 10.1101/2020.11.27.401869

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

Gao, F.·Yang, Y.·Zhu, H.·Wang, J.·Xiao, D.·Zhou, Z.·Dai, T.·Zhang, Y.·Feng, G.·Li, J.·Lin, B.·Xie, G.·Ke, Q.·Li, P.·Sheng, X.·Wang, H.·Yan, L.·Lao, C.·Li, M.·Lu, Y.·Zhao, J.·Feng, S.·Du, X.·Wu, D.

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Abstract

Ultrahigh dose-rate (FLASH) radiotherapy has attracted immense attention because of its tumor control efficiency and healthy tissue protection during preclinical experiments with electrons, kilo-voltage X-rays, and protons. Using high-energy X-rays (HEXs) in FLASH is advantageous owing to its deep penetration, small divergence, and cost-effectiveness. This is the first report on the implementation of HEXs with FLASH (HEX-FLASH) and its corresponding application in vivo. With a high-current and high-energy superconducting linear accelerator, FLASH with a good dose rate and high penetration was achieved. Breast cancers artificially induced in BAL b/c mice were efficiently controlled, and normal tissues surrounding the thorax/abdomen in C57BL/6 mice were protected from radiation with HEX-FLASH. Theoretical analyses of cellular responses following HEX-FLASH irradiation were performed to interpret the experimental results and design further experiments. Thus, this study highlights the generation of HEX-FLASH for the first time and its potential in future clinical applications.

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Gao, F., Yang, Y., Zhu, H., Wang, J., Xiao, D., Zhou, Z., Dai, T., Zhang, Y., Feng, G., Li, J., Lin, B., Xie, G., Ke, Q., Li, P., Sheng, X., Wang, H., Yan, L., Lao, C., Li, M., Lu, Y., Zhao, J., Feng, S., Du, X., Wu, D.. 2020-11-28. First demonstration of the FLASH effect with ultrahigh dose-rate high energy X-rays. https://doi.org/10.1101/2020.11.27.401869

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