Impact of the Sensor Electrical Noise on Ionoacoustic Dose Reconstruction using 200 MeV Clinical Proton Beam

Ionoacoustic dosimetry has emerged as a promising technique for real-time dose verification in proton therapy, where conventional methods like Electronic Portal Imaging Devices (EPIDs) are ineffective due to the absence of an exit dose beyond the Bragg peak. This study evaluates the impact of realistic sensor noise on the ionoacoustic reconstruction of dose distributions generated by a 200 MeV proton beam, simulated using the k -Wave toolbox. Different signal-to-noise ratios (SNRs) were modeled by varying the delivered dose per pulse across a range of clinically relevant values ($1-100 \mathrm{mGy}$). The quality of the reconstructed dose distributions was assessed using gamma index analysis at $1 \% / 1$ mm and $3 \% / 3 \mathrm{~mm}$ criteria. Results demonstrate that, even under significant noise conditions, accurate dose reconstructions are achievable without the need for temporal averaging, provided sufficient per-pulse dose. These findings support the feasibility of ionoacoustic dosimetry for online, high-precision proton therapy monitoring and suggest pathways for future experimental validation and clinical translation.