Journal of nuclear medicine : official publication, Society of Nuclear Medicine
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Comparative Study
Sensitivity Comparison of 68Ga-OPS202 and 68Ga-DOTATOC PET/CT in Patients with Gastroenteropancreatic Neuroendocrine Tumors: A Prospective Phase II Imaging Study.
Radiolabeled somatostatin (sst) receptor agonists are integral to the diagnosis of gastroenteropancreatic neuroendocrine tumors (NETs), but detection rates, especially of liver metastases, remain limited even with PET/CT. 68Ga-OPS202 (68Ga-NODAGA-JR11; NODAGA = 1,4,7-triazacyclononane,1-glutaric acid-4,7-acetic acid and JR11 = Cpa-c(dCys-Aph(Hor)-dAph(Cbm)-Lys-Thr-Cys)-dTyr-NH2)), a novel radiolabeled sst receptor antagonist with a high affinity for the sst2 receptor, has the potential to perform better than sst receptor agonists. Here, we present the results of the phase II component of a phase I/II study that evaluated the sensitivity of 68Ga-OPS202, compared with the reference compound, 68Ga-DOTATOC (an sst receptor agonist), in PET imaging. Methods: Patients received a single 150-MBq intravenous injection of 68Ga-DOTATOC (15 μg of peptide) and 2 single 150-MBq intravenous injections of 68Ga-OPS202 (15 μg of peptide at visit 1 and 50 μg at visit 2). ⋯ There were no significant differences in image contrast, sensitivity, or positive predictive values between the 2 68Ga-OPS202 peptide doses, indicating a high reproducibility. Conclusion: Preliminary diagnostic efficacy data from this phase II study indicate that 68Ga-OPS202 has high sensitivity for the detection of gastroenteropancreatic NETs. Further studies in larger patient populations are warranted.