Comparison of Al18F-NOTA-LM3 With 68Ga-DOTATATE and 68Ga-NODAGA-LM3 PET/CT in Patients With Well-differentiated Neuroendocrine Tumors

40 patients will be enrolled in this arm. The first enrolled 8 patients will undergo serial whole-body PET/CT scans at multiple time points (5, 15, 30, 45, 60, and 120 min) after injection of Al18F-NOTA-LM3. The following patients will undergo a whole-body PET/CT scan 60-120 minutes after injection.

All patients in arm A will undergo a whole-body PET/CT scan 40-60 minutes after injection of 68Ga-DOTATATE. 68Ga-DOTATATE PET/CT and Al18F-NOTA-LM3 PET/CT should be performed within a week and the interval between the two scans at least 24h.

40 patients will be enrolled in this arm. All patients will undergo a whole-body PET/CT scan 60-120 minutes after injection.

All patients in arm B will undergo a whole-body PET/CT scan 40-60 minutes after injection of 68Ga-NODAGA-LM3. 68Ga-NODAGA-LM3 PET/CT and Al18F-NOTA-LM3 PET/CT should be performed within a week and the interval between the two scans at least 24h.