Total-body 18F-FDG PET/CT: more choices to promote clinical scanning efficiency

The study aims to maximize clinical scan efficiency for Total-body (TB) 18F-FDG PET/CT systems by optimizing scan strategies based on theoretical models and clinical experience from a single center. This prospective study include two parts. The first part involved simulation experiments using theoretical models to maximize patient throughput and/or minimizing radiotracer activity across four clinical scanning scenarios: fixed working time, predetermined radiotracer activity, integration of various injection activity regimens for a fixed number of patients, and incorporation of dynamic scans into routine static scans within a fixed working time. The optimal scan strategies for these scenarios were then proposed. The second part validated the estimated throughput results through high-throughput tests performed in the real clinical settings with an fixed working time of 8 h. Under a fixed working time of 8 h, the theoretical patient throughput for full-activity, half-activity, 1/3-activity, and 1/10-activity injection regimens was 60, 48, 43, 30 patients, respectively. The corresponding real clinical throughput achieved was 60, 49, 48, 28 patients. For a total 18F-FDG activity of 37,000 to 148,000 MBq (1 to 4 Ci), the 1/3-activity injection regimen yielded the highest patient throughput, ranging 52 to 72 patients. Strategically combining various injection activity regimens could reduce radiotracer activity consumption. Additionally, placing full-activity dynamic scans after routine static scans for full-activity, half-activity, and 1/3-activity, and before 1/10 activity, proved to ba more economical strategies. Optimized scan strategies for typical clinical scenarios of TB 18F-FDG PET/CT systems were proposed, which could promote clinical scan efficiency and accommodate diverse clinical requirements. These strategies enable centers to balance throughput and activity efficiency while maintaining diagnostic quality.