⁶⁴Cu-DOTATATE PET for Neuroendocrine Tumors: A Prospective Head-to-Head Comparison with ¹¹¹In-DTPA-Octreotide in 112 Patients

Abstract

Neuroendocrine tumors (NETs) can be visualized using radiolabeled somatostatin analogs. We have previously shown the clinical potential of 64 Cu-DOTATATE in a small first-in-human feasibility study. The aim of the present study was, in a larger prospective design, to compare on a head-to-head basis the performance of 64 In-diethylenetriaminepentaacetic acid (DTPA)-octreotide ( 111 In-DTPA-OC) as a basis for implementing 64 Cu-DOTATATE as a routine. Methods: 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. Results: Eightyseven 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 5 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. Conclusion: 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.

Somatostatin Receptor 2–Targeting Compounds

“…Compared with 68 Ga-SSA PET tracers, this tracer has a longer half-life and lower positron decay energy, theoretically leading to a favorable tumor-to-background ratio and better detection of small lesions (50). In a direct comparison, the patient-based sensitivities were equal, but [ 64 Cu-DOTA 0 -Tyr 3 ] octreotate had a higher lesion detection rate and was superior at identifying affected organs (51).…”

Head-to-Head Comparison of 64Cu-DOTATATE and 68Ga-DOTATOC PET/CT: A Prospective Study of 59 Patients with Neuroendocrine Tumors

“…Data on the diagnostic performance of 64 Cu-DOTATATE PET versus 111 In-DTPA-octreotide SPECT in NET patients were presented recently (14). Twice as many lesions were found by 64 Cu-DOTATATE, and additional organ involvement was detected in one third of the enrolled patients.…”

“…Compared with 111 In-DTPAoctreotide, it was superior in both radiation dose and lesion detection rates when tested on a head-to-head basis in 112 patients (14,20). The lower positron range of 64 Cu than of 68 Ga theoretically leads to a better spatial resolution, and the physical half-life of 12.7 h makes 64 Cu-DOTATATE attractive for routine use in a clinical imaging setting.…”

“…The PET-based tracers, however, have major advantages over g-emitting tracers, in terms of both detection rate and the quantitative nature (9)(10)(11)(12)(13)(14). The Nordic guidelines state that PET is preferred over SPECT in the diagnostic work-up of NETs.…”

NEN — the role of somatostatin receptor scintigraphy in clinical setting

“…Use of different radionuclides and radiolabeling strategies influences peptide's SSTR affinity and changes radiopharmaceutical properties. By now, 18 F-SSTR tracers were synthesized but they did not succeed as much as tracers radiolabeled with for example 64 Cu, such as 64 Cu-DOTATATE [48] or 64 Cu-TETATOC [49]. It is expected that tracers based on 64 Cu provide images with better resolution, higher sensitivity and will have favorable dosimetry allowing their therapeutic use.…”