Objectives 64Cu-DOTATATE is a new PET tracer for somatostatin receptor imaging. 64Cu-DOTATATE may potentially have a higher sensitivity than the current gold standards, due to advantages of 64Cu compared to 68Ga. The aim was to test this hypothesis on a head to head basis in neuroendocrine tumor patients (NET).
Methods Fifty-nine NET patients were scanned with 64Cu-DOTATATE and 68Ga-DOTATOC PET/CT and discordant lesions were verified through follow-up. Both scans were made within a week (1-5 days apart).
Results A total of 701 lesions were concordantly detected on both 64Cu-DOTATATE and 68Ga-DOTATOC PET/CT scans while additional 68 lesions were found by only one of the two scans. 64Cu-DOTATATE showed 42 discordant lesions of which 33 were found to be true positive on follow up. 68Ga-DOTATOC showed 26 discordant lesions, but only 7 were found to be true positive on follow up. False positives were mainly lymph node lesions. Eighty-three percent of the additional true positive lesions were found by 64Cu-DOTATATE. 64Cu-DOTATATE and 68Ga-DOTATOC discovered additional true lesions in 13 and 3 patients, respectively. All patients with additional lesions also had concordant lesions found by both scans.
Conclusions Although patient based sensitivity was the same for 64Cu-DOTATATE and 68Ga-DOTATOC in this cohort, more lesions were found by 64Cu-DOTATATE. Furthermore the shelve life of more than 24 hours and a scan window of at least 3 hours make 64Cu-DOTATATE logistically attractive to use in the clinic.
- Neuroendocrine tumors
- Somatostatin receptor imaging