Investigation of in vivo beam range verification in carbon ion therapy using the Doppler Shift Effect of prompt gamma: A Monte Carlo simulation study

Abstract Carbon ion therapy has received increasing attention because of its excellent physical dose distribution and high biological effect comparing against the conventional radiotherapy. However, the range uncertainty is still a major issue that limits further improvement of the treatment efficiency. Hence, we propose a novel method for reducing the range uncertainty in carbon ion therapy based on the Doppler Shift Effect of prompt gamma (PG), which can quantify the average carbon energy by the significant energy shift of the 4.44 MeV  PG in the spectrum and then calibrate the range. Specifically, the influences of heterogeneity, initial carbon beam configuration, and detected direction are thoroughly discussed using the Monte Carlo simulation in this paper. Results show a moderate difference (