Preliminary study of low-pressure ionization chamber for online dose monitoring in FLASH carbon ion radiotherapy

Xinle Lang; Zhengguo Hu; Zulong Zhao; Kai Zhou; Zhiguo Xu; Min Li; Ruishi Mao; Faming Luo; Chuan Huang; Xincai Kang; Juan Li; Xiaotao Liu; Libin Zhou; Guoqing Xiao

doi:10.1088/1361-6560/ad13d0

Preliminary study of low-pressure ionization chamber for online dose monitoring in FLASH carbon ion radiotherapy

Phys Med Biol. 2024 Jan 8;69(2). doi: 10.1088/1361-6560/ad13d0.

Authors

Xinle Lang^{1

2}, Zhengguo Hu^{1

2}, Zulong Zhao¹, Kai Zhou¹, Zhiguo Xu¹, Min Li¹, Ruishi Mao^{1

2}, Faming Luo^{1

2}, Chuan Huang^{1

3}, Xincai Kang¹, Juan Li¹, Xiaotao Liu¹, Libin Zhou¹, Guoqing Xiao^{1

2}

Affiliations

¹ Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou 730000, Gansu, People's Republic of China.
² University of Chinese Academy of Sciences, School of Nuclear Science and Technology, Beijing 100049, People's Republic of China.
³ School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, Gansu, People's Republic of China.

PMID: 38064745
DOI: 10.1088/1361-6560/ad13d0

Abstract

The FLASH effect of carbon ion therapy has recently attracted significant attention from the scientific community. However, the radiobiological mechanism of the effect and the exact therapeutic conditions are still under investigation. Therefore, the dosimetry accuracy is critical for testing hypotheses about the effect and quantifying FLASH Radiotherapy. In this paper, the FLASH ionization chamber at low-pressure was designed, and its dose rate dependence was verified with the Faraday cup. In addition, the dose response was tested under the air pressure of the ionization chamber of 10 mbar, 80 mbar and 845 mbar, respectively. The results showed that when the pressure was 10 mbar, the dose linearity was verified and calibrated at the dose rate of ∼50 Gy s^-1, and the residuals were less than 2%. In conclusion, the FLASH ionization chamber is a promising instrument for online dose monitoring.

Keywords: FLASH; carbon ion therapy; dosimetry; low-pressure ionization chamber.

MeSH terms

Heavy Ion Radiotherapy*
Radiometry* / methods
Radiotherapy Dosage