FAPI-74 PET/CT using either 18F-AlF or cold-kit 68Ga labeling: Biodistribution, radiation dosimetry, and tumor delineation in lung cancer patients
Researchers assessed the time-dependent tumor uptake and tracer biodistribution as well as estimated absorbed dose for 18F-FAPI (fibroblast activation protein inhibitor)-74 PET/CT scans via examinations conducted under a medical indication to aid tumor volume delineation for guiding radiotherapy in patients suffering from lung cancer. Additionally, they showed proof of mechanism for 68Ga-FAPI-74 PET/CT following tracer labeling at ambient temperature. This study involved 10 cases of lung cancer, in which PET scans were obtained at 10 minutes, 1 hour, and 3 hours following administration of 259 ± 26 MBq of 18F-FAPI-74. Experts semiquantitatively assessed physiologic biodistribution and tumor uptake, based on SUV at each time point. At 1 hour post-injection, the highest contrast was evident in primary tumors, lymph nodes, and distant metastases, with an SUVmax of more than 10. Experts noted that FAPI-74 PET/CT had high contrast and low radiation burden, and thus, multiple clinical applications are supported. Centralized large-scale generation of 18F-FAPI-74 or decentralized cold-kit labeling of 68Ga-FAPI-74 permits flexible routine use.