A High Speed, Solid, 3D Dosimeter Prototype

An important aspect of modern radiation therapy methods is a verification of dosimetric radiation delivery. To perform quality assurance of the dose delivery in a matter of minutes, a novel, solid detector prototype was built with water equivalent scintillators that were machined, cut, and arranged in a three-dimensional array. Roughly 1600 polystyrene rods doped with the organic scintillating agents P-Terphenyl and BisMSB were used to build the prototype. High-frame rate CCD cameras captured cross-sectional images of two sides of the scintillators. A neural network then used the scintillator images to reconstruct a three-dimensional image of energy distribution. This prototype was tested using a 9 MeV electron beam with conventional and ultra high dose rates, up to 600 Gy/s, at The Ohio State University Comprehensive Cancer Center. Here, the prototype design and construction details, the deep learning studies performed with GEANT4/GATE simulations, as well as the detector performance during beam tests are reported.