Utilizing Pencil Beam Scan Dynamics and a Scintillation Screen to produce 3D Dose Distribution of Proton Beams

This study describes a method for producing volumetric dose profiles of proton beams from 2D slices of optical scintillation images. The method relies on a high frame rate camera acquisition (100 frames per second), the spot scanning capabilities of current proton pencil beam scanning systems, and a water equivalent scintillation screen. The acquired slices are corrected for optical blurring and ionization quenching and stacked to produce volumetric dose distribution. The volumetric optical dose profile had a pass rate of 98.3% for 2%/2mm local gamma analysis, suggesting the method can accurately measure dose profiles. The method can potentially image all clinical proton beams for pencil beam scanning systems and can extend to imaging patient plans, with further verification.