Development of a Gamma-Ray Detection System for Targeted Alpha Therapy and Global Research Trends

Targeted alpha therapy (TAT) is a highly precise cancer treatment technique that uses alpha particles to selectively deliver radiation to tumor cells.Due to the short path length and high energy of alpha emissions, accurate localization is critical for therapeutic success.However, because alpha particles cannot be directly detected in vivo, gamma rays emitted during radionuclide decay must be used to visualize treatment delivery.In response to this need, a multilayer gamma detection system was designed using yttrium aluminum garnet (YAG), lanthanum bromide (LaBr), and bismuth germanate (BGO), each selected for their complementary interaction properties.The cylindrical detector system, with a total length of 150 centimeters and concentric layer radii of 30, 40, and 50 centimeters, was optimized using GEANT4 Monte Carlo simulations.The system achieved gamma detection efficiencies of 10.5% and 12.3% for 218 keV and 440 keV photons, respectively, which are key emissions from Actinium-225.The inclusion of lanthanum bromide enabled high energy resolution of 8.4% to 10% (full width at half maximum), and spatial resolution was maintained at approximately 3 millimeters with Gaussian correction methods.Comparative studies of advanced gamma imaging technologies show that high-resolution systems with real-time signal processing and submillimeter spatial precision are actively being developed using alternative detector types, such as resistive plate chambers.These developments aim to improve both the performance and cost-efficiency of theranostic imaging systems.Collectively, this work demonstrates the feasibility of constructing a real-time imaging platform for alpha particle therapy using multilayer gamma detectors.The optimized system offers sufficient performance for spatial and energy resolution to enable real-time dosimetric feedback during treatment, and provides a strong foundation for future expansion into clinical applications and personalized therapy planning.