Proton Radiography study using a passive scattered beam

The use of high-energy proton beams enables to delivering high doses to target volumes, while sparing organs at risk compared to X-ray radiotherapy. However, the protons advantages cannot be fully exploited because the range (i.e the stopping powers) of protons in matter is not accurately known. Indeed, the proton stopping powers are obtained by an empirical conversion of X-CT Hounsfield Units that leads to systematic errors in proton range calculation. Several publications demonstrated that proton imaging was feasible and could be used to directly obtain proton stopping powers. However, the main drawback of p-CT or proton radiography (p-RG) is the limited spatial resolution, induced by the multiple Coulomb scattering of protons with nuclei.