Clinical Application of 18F-AlF-NOTA-Octreotide PET/CT in Combination With 18F-FDG PET/CT for Imaging Neuroendocrine Neoplasms

Objectives The study is to evaluate biodistribution, dosimetry, safety, and clinical usefulness of 18 F-AlF-NOTA-octreotide ( 18 F-OC) PET/CT in combination with 18 F-FDG PET/CT for detection of neuroendocrine neoplasms (NENs). Methods The biodistribution, dosimetry, and safety of 18 F-OC were evaluated in 3 healthy volunteers. Twenty-two NEN patients underwent PET/CT at 60 minutes after intravenous injection of 3.7 to 4.44 MBq (0.1–0.12 mCi) per kilogram of body weight of 18 F-OC. This was followed by 18 F-FDG PET/CT within a 2-week period. Results 18 F-OC was well tolerated by all healthy volunteers and NEN patients. The calculated effective dose of 18 F-OC was 0.023 ± 0.002 mSv/MBq. In NEN patients, we observed prominent 18 F-OC tumor uptake and high tumor-to-background ratios. Tumor uptake of 18 F-OC was greater than that of 18 F-FDG, and this was particularly evident in G2 NENs (median SUVmax, 45.6 vs 4.3; P < 0.015). Tumor uptake of 18 F-OC or 18 F-FDG was significantly correlated with tumor differentiation ( P < 0.05). Dual tracer PET/CT detected more lesions and also yielded information on the biological status of tumors. Conclusions The tracer 18 F-OC exhibited favorable safety and dosimetry profiles. 18 F-OC provided superior imaging of well-differentiated NENs and significantly higher tumor-to-background ratio compared with 18 F-FDG. Combining 18 F-FDG with 18 F-OC PET/CT has the potential to improve NEN staging and management of patient treatment.