Characterization of an in-beam PET prototype for proton therapy with different target composition

Positron emission tomography is a valuable method for in situ and non invasive monitoring of the accuracy of the treatment in hadron therapy. It takes advantage of short lived β⁺- emitters spontaneously produced in the biological tissues during irradiation, by means of projectile and/or target nuclei fragmentations. Although β⁺- emitter production cross-sections and hadron stopping power exhibit a different dependence on the hadron energy, it is still possible to extract non invasively in vivo information about dose localization reconstructing the distribution of positron annihilation points.