Abstract

Info

Author(s):: HE Shiqi; YANG Yan; School of Physics and Technology, Wuhan University, Wuhan 430072, China

Keywords:: Keywords: Bragg peak; proton-excited thermoacoustic signal; travel time inversion; localization

Abstract:: Abstract: Objective To locate the Bragg peak of proton beam using proton-excited acoustic signal and analyze its feasibility in proton therapy. Methods Kwave toolkit was used to simulate the propagation process of the proton beam in water, and sensors were placed to receive the travel time data of γ-wave generated by proton excitation. The received travel time data were inverted to obtain the correction of the Bragg peak position, thereby localizing the Bragg peak. Results In the uniform medium, when the initial Bragg peak position was within 5 cm of the target Bragg peak position, the travel time data obtained by Kwave simulation was used for localization. In the case of no noise, the positioning error was within 1.3 mm; and after noise adding, the localization error was still within 3 mm. The precise localization of the Bragg peak was achieved by the inversion of the travel time data obtained by the linear travel time ray tracing algorithm of wavefront expansion. Conclusion When using proton-excited acoustic signals, only a small number of sensors are needed to localize the Bragg peaks of the proton beam. Although the accuracy of the travel time data has a certain effect on the localization algorithm, it is found through the noise-adding experiment that the proposed algorithm has good robustness and convergence.