Acoustic pulse generated in a patient during treatment by pulsed proton radiation beam

Acoustic pulses were detected from a patient treated by a pulsed proton radiation beam. The dose rate of the proton beam was 0.3 cGy/pulse. The signals from 100 to 700 pulses were accumulated to improve the signal to noise ratio. After accumulation, the random noise level was negligibly small compared to the signal. These results suggest the feasibility of non‐invasive monitoring of proton dose distributions in patients by sensing acoustic pulses generated during irradiation by a pulsed proton radiation beam.