Speaker
Description
A method for real-time, in vivo verification of dose delivery during Very High Energy Electron (VHEE) therapy is presented. The method involves detecting Bremsstrahlung radiation emitted when VHEE beams interact with matter, using LYSO scintillation detectors coupled to photomultiplier tubes (PMTs). A cylindrical polymethyl methacrylate (PMMA) phantom was irradiated with 80 and 150 MeV electron pencil beams at the Beam Test Facility in Frascati (INFN). Two detectors placed orthogonally to the beam axis measured emitted Bremsstrahlung photons, with lead collimators selecting perpendicular photons. A motorized stage moved the phantom longitudinally to collect data along the beam path. A Continuous Normalizing Flow neural network predicted the delivered dose based on the measured radiation distribution. The spatial distribution of detected events along the beam path agreed with GEANT4 Monte Carlo simulations, confirming the detector system's accuracy. The predicted dose from the neural network also showed good agreement with Monte Carlo-calculated doses, demonstrating the system's capability to reliably measure dose distributions in the phantom. This study demonstrates the feasibility of using Bremsstrahlung radiation detection and neural network modeling for real-time, in vivo dose verification in VHEE therapy. Future work will focus on designing and constructing a prototype for three-dimensional dose distribution measurement to enhance treatment quality assurance
