Objective: To evaluate the diagnostic efficacy of 18F-AlF-NOTA-octreotide (18F-OC) PET/CT compared with that of 68Ga-DOTATATE PET/CT.
Materials and methods: Twenty patients (mean age: 52.65 years, range: 24-70 years) with biopsy-proven neuroendocrine neoplasms (NENs) were enrolled in this prospective study. We compared the biodistribution profiles in normal organs based on the maximum standard uptake value (SUVmax) and mean standard uptake value (SUVmean), and uptake in NEN lesions by measuring the SUVmax on 18F-OC and 68Ga-DOTATATE PET/CT images. The tumor-to-liver ratio (TLR) and tumor-to-spleen ratio were calculated by dividing the SUVmax of different tumor lesions by the SUVmean of the liver and spleen, respectively. The Wilcoxon signed-rank test was used to compare nonparametric data. Data were expressed as the median (interquartile range).
Results: In most organs, there were no significant differences in the biodistribution of 68Ga-DOTATATE and 18F-OC. 18F-OC had significantly lower uptake in the salivary glands and liver than 68Ga-DOTATATE. 18F-OC detected more lesions than 68Ga-DOTATATE. The uptake of 18F-OC in the tumors was higher in most patients, but the difference was not statistically significant relative to that of 68Ga-DOTATATE. However, the TLRs of 18F-OC were higher in most patients, including for lesions in the liver (p = 0.02) and lymph nodes (p = 0.02).
Conclusion: Relative to 68Ga-DOTATATE, 18F-OC possesses favorable characteristics with similar image quality and satisfactory NEN lesion detection rates, especially in the liver due to its low background uptake. 18F-OC therefore offers a promising clinical alternative for 68Ga-DOTATATE.