We prospectively enrolled 112 patients with pathologically confirmed NETs of gastroenteropancreatic or pulmonary origin. All patients underwent both PET/CT with (64)Cu-DOTATATE and SPECT/CT with (111)In-DTPA-OC within 60 d. PET scans were acquired 1 h after injection of 202 MBq (range, 183-232 MBq) of (64)Cu-DOTATATE after a diagnostic contrast-enhanced CT scan. Patients were followed for 42-60 mo for evaluation of discrepant imaging findings. The McNemar test was used to compare the diagnostic performance.
Eighty-seven patients were congruently PET- and SPECT-positive. No SPECT-positive cases were PET-negative, whereas 10 false-negative SPECT cases were identified using PET. The diagnostic sensitivity and accuracy of (64)Cu-DOTATATE (97% for both) were significantly better than those of (111)In-DTPA-OC (87% and 88%, respectively, P = 0.017). In 84 patients (75%), (64)Cu-DOTATATE identified more lesions than (111)In-DTPA-OC and always at least as many. In total, twice as many lesions were detected with (64)Cu-DOTATATE than with (111)In-DTPA-OC. Moreover, in 40 of 112 cases (36%) lesions were detected by (64)Cu-DOTATATE in organs not identified as disease-involved by (111)In-DTPA-OC.
With these results, we demonstrate that (64)Cu-DOTATATE is far superior to (111)In-DTPA-OC in diagnostic performance in NET patients. Therefore, we do not hesitate to recommend implementation of (64)Cu-DOTATATE as a replacement for (111)In-DTPA-OC.