Prompt Gamma Timing range verification for scattered proton beams

Range verification is a very important point in order to fully exploit the physical advantages of protons compared to photons in cancer irradiation. Recently, a simple method has been proposed which makes use of the time of flight of protons in tissue and the promptly emitted secondary photons along the proton path (Prompt Gamma Timing, PGT). This has been considered so far for monoenergetic pencil beams only. In this work, it has been studied whether this technique can also be applied in passively formed irradiation fields with a so called spread out Bragg peak. Time correlated profiles could be recorded, which show a trend that is consistent with theoretical predictions.