Prompt Gamma Imaging for Dose Monitoring in Carbon Ion Radiation Therapy: A Simulation Study

In-vivo range verification has been a hot topic in particle therapy since two decades. Many efforts have been focused on proton therapy, while fewer studies were conducted considering a beam of carbon ions. In this work we show, through a simulation study, that it is possible to recognize in a pixelated detector a Prompt Gamma profile generated by the interaction of ions with matter (which is correlated to the Bragg curve) despite a very large neutron background typical of carbon-ion irradiation. In addition, we estimate of the theoretical uncertainty on the particle range determination, considering a Carbon pencil beam with different numbers of ions. For this purpose, we performed Monte Carlo simulations with the software FLUKA and, for data analysis, we implemented three different analytical methods to estimate the theoretical accuracy in the range retrieval for the simulated set-up. Results positively confirmed the correlation between the Bragg peak and the detection profiles. The analysis of the simulation data brought to a precision of few millimeters with a realistic spill intensity, with the three cited methods coherent between them in their predictions. Finally, due to the positive indications of our study, we planned an experimental campaign to verify our simulated results and further investigate if the Prompt Gamma Imaging technique can be applied to carbion ion treatments.