Abstract
Somatostatin receptor imaging is a valuable tool in the diagnosis, follow-up and treatment planning of neuroendocrine tumor (NET) patients. Positron emission tomography (PET) based tracers using 68Ga as the radioisotope have in most centers replaced single-photon emission tomography (SPECT) based tracers as the gold standard. 64Cu-DOTATATE is a new PET tracer that has been shown to be far superior compared to the SPECT tracer 111In-DTPA-octreotide. Due to advantages of 64Cu compared to 68Ga, we hypothesize that the tracer could have a higher sensitivity than 68Ga-based tracers. To test this hypothesis, we compared on a head-to-head basis the diagnostic performance of 64Cu-DOTATATE with that of 68Ga -DOTATOC in NET patients. Methods: Fifty-nine NET patients were scanned both with 64Cu-DOTATATE and 68Ga-DOTATOC PET and computed tomography (CT) and compared on a head-to-head basis. Discordant lesions were verified during at least 30 months of follow-up. Results: A total of 701 lesions were concordantly detected on both 64Cu-DOTATATE and 68Ga-DOTATOC PET/CT scans while an additional 68 lesions were found by only one of the scans. 64Cu-DOTATATE showed 42 lesions not found on 68Ga-DOTATOC of which 33 were found to be true positive on follow up. 68Ga-DOTATOC showed 26 lesions not found on 64Cu-DOTATATE of which 7 were found to be true positive on follow up. False positives were mainly lymph node lesions. Accordingly, 83% of the additional true lesions only found on one of the scans were found by 64Cu-DOTATATE. On a patient-basis additional true lesions were found by 64Cu-DOTATATE and 68Ga-DOTATOC in 13 and 3 patients, respectively. All patients with additional lesions also had concordant lesions found by both scans. Conclusion: 64Cu-DOTATATE possesses advantages in the detection of lesions in NET patients compared to 68Ga-DOTATOC. Although patient based sensitivity was the same for 64Cu-DOTATATE and 68Ga-DOTATOC in this cohort, significant more lesions were detected by 64Cu-DOTATATE. Furthermore, the shelf life of more than 24 hours and the scan window of at least 3 hours make 64Cu-DOTATATE very favorable and easy to use in the clinical setting.
- Neuroendocrine
- Oncology: Endocrine
- PET/CT
- 64Cu-DOTATATE
- 68Ga-DOTATOC
- PET/CT
- neuroendocrine tumors
- somatostatin receptor imaging
- Copyright © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.