Feasibility of Performing Clinical Low Dose and Fast Brain PET Imaging Enabled by SiPM Digital Photon Counting PET/CT

Purpose: To evaluate the feasibility of performing low dose and fast brain FDG-PET imaging in clinical and clinical trials using SiPM digital photon counting (DPC) PET/CT. Materials and Methods: 10 oncology patients with breast cancer (BMI=33±7) were enrolled to assess neurometabolic changes and imaged before and after chemotherapy (interval=77±10 days). Low dose FDG brain PET (3.1±0.2mCi) was performed on a DPC PET/CT (Vereos, Philips) with 0.5, 1, 2 and 5 min frame durations compared to the standard of care (SOC) 10min frame duration. All data were reconstructed with 2mm isotropic voxels using TOF 3D-OSEM, and assessed with 90 brain regions using MIMSoftware and Atlas mapping. SUV & Z-Score were calculated. 3D-Hoffman phantom PET scans (0.5-10min, 0.6-2mCi FDG) were performed. Blind image reviews were performed by radiologists. Results: Compared to the 10min SOC PET, an average of 2.5±3.0%, 1.7±2.3%, 1.2±1.5% and 0.7±0.9% SUVmean difference across 90 regions of all patients were obtained for low dose PET of 0.5, 1, 2 and 5min, and no significant differences (p>0.05) in % change of therapy response were found for low dose brain PET of 1min (-7±22%), 2min (-6±22%) and 5min (-7±21%) except at 0.5 min (6±22%, p