Range verification of proton radiotherapy with prompt gamma rays

In-vivo range verification systems for incident protons recently utilize positron emission tomography (PET) based on the phenomenon of positron-emitting nuclei (PEN). However, recent investigations are suggesting that the range can be verified also from the prompt gamma (PG) photon emissions generated from proton interactions. In this work we investigate using the Geant4 Monte Carlo toolkit the clinical viability of a theoretical sequential detector system to verify the range of protons in proton radiotherapy by the PG method for simple geometries and beam configurations. The results show a correlation between selected emitted PG rays and the incident protons range and suggest that our detector system is capable of in-vivo range monitoring for energies typical of radiation oncology applications. Future work will include implementing more realistic scenarios and optimizing current detector parameters.