Purpose: This is a head-to-head comparison between Gallium-68 Prostate Specific Membrane Antigen (68Ga-PSMA-11) and 18F-Fluciclovine Positron Emission Tomography/Computed Tomography (PET/CT) in a series of 10 patients with prostate cancer (PCa) recurrence.
Methods: 288 patients with PCa recurrence were enrolled in a prospective study of 68Ga-PSMA-11 PET/CT imaging for recurrent disease localization (NCT02940262). We retrospectively identified 10 patients who underwent clinical indicated 18F-Fluciclovine PET/CT prior enrollment.
Results: The median time between´ both scans was 2.3 months (range 0.2-4.2). The median PSA value was 1.0 ng/ml (mean 4.7 ng/ml; range 0.13-18.1) and 1.1 ng/ml (mean 6.2 ng/ml; range 0.24-31.3) at the time of 18F-Fluciclovine and 68Ga-PSMA-11 PET/CT, respectively. 5/10 patients (50%) were negative on 18F-Fluciclovine PET/CT but showed positive results on 68Ga-PSMA-11 PET/CT. 2/10 patients (20%) had both positive 18F-Fluciclovine and 68Ga-PSMA-11 PET/CT but 68Ga-PSMA-11 PET/CT showed additional lymph nodes (LN) metastasis. 3/10 patients (30%) had both negative 18F-Fluciclovine and 68Ga-PSMA-11 PET/CT.
Conclusion: This case series suggests improved detection rates of 68Ga-PSMA-11 when compared to 18F-Fluciclovine PET/CT in patients with recurrent PCa. Prospective trials designed to directly compare 68Ga-PSMA-11 and 18F-Fluciclovine PET/CT should be initiated.