On the feasibility of real time imaging in radiotherapy using antiproton beams

Antiprotons whose potential in clinical applications has not yet been fully studied and explored, interact in a way similar to the widely used protons. The great advantage of antiprotons over protons is that at the end of their path annihilate and release about 1.88GeV more energy. Although many particles are produced by annihilation most of them escape from the target. Detecting a portion of these particles during patient's irradiation would offer the possibility to monitor the beam in the target in real time. In the current work we investigate the feasibility of real time imaging during radiotherapy by using antiproton beam. In this study a prostate case is simulated using one field and given a typical dose fraction of 2Gy to the target. Monte Carlo code is used to calculate the energy spectrum of the most prominent particles that escape from the target which could be detected outside the patient, as well as the degree of scattering of these particles, as an indication of merit for their use in order to produce an image which represents the absorption of the beam in the target. Results based on these criteria suggest that real time imaging is possible by detecting either charged pions or photons which mainly come from π0 decays or e+e− annihilation.