Self-correction in protoacoustic range verification for different proton pulse widths

Abstract

In proton therapy, the acoustic waves produced by the proton radiation can be measured to determine the proton range. The k-Wave MATLAB toolbox is used to simulate the propagation process of pressure waves in time and space. By measuring the time-of-flight (TOF) of the pressure wave, the Bragg peak distance is obtained. In this study, we obtain the error maps for different pulse widths, which show that angle is the influencing factor of protoacoustic TOF range calculations. To reduce the systematic errors, the angle θ (θ is the angle between the proton beam direction and the vector passing Bragg peak and the sensor) is mapped to the systematic error using a fifth-order polynomial to obtain the correction factor, . The presented simulations show that by correcting the distance with , the systematic error of protoacoustic range verification can be controlled within 1mm under different proton pulses widths.