Comparison of 68Ga-PSMA-11 and 18F-Fluciclovine PET/CT in a Case Series of 10 Patients with Prostate Cancer Recurrence

Abstract

This was a head-to-head comparison between ⁶⁸Ga-labeled prostate-specific membrane antigen (PSMA)-11 and ¹⁸F-fluciclovine PET/CT in a series of 10 patients with prostate cancer (PCa) recurrence. Methods: In total, 288 patients with PCa recurrence were enrolled in a prospective study of ⁶⁸Ga-PSMA-11 PET/CT imaging for recurrent disease localization (ClinicalTrials.gov identifier NCT02940262). We retrospectively identified 10 patients who underwent clinically indicated ¹⁸F-fluciclovine PET/CT prior to enrollment. Results: The median time between the 2 scans was 2.2 mo (range, 0.2-4.2 mo). The median prostate-specific antigen (PSA) value was 1.0 ng/mL (mean, 4.7 ng/mL; range, 0.13-18.1 ng/mL) and 1.1 ng/mL (mean, 6.2 ng/mL; range, 0.24-31.3 ng/mL) at the time of ¹⁸F-fluciclovine and ⁶⁸Ga-PSMA-11 PET/CT, respectively. Five of 10 patients (50%) were negative with ¹⁸F-fluciclovine but positive with ⁶⁸Ga-PSMA-11 PET/CT. Two of 10 patients (20%) were positive with both ¹⁸F-fluciclovine and ⁶⁸Ga-PSMA-11 PET/CT, but ⁶⁸Ga-PSMA-11 PET/CT showed additional lymph nodes metastasis. Three of 10 patients (30%) were negative with both ¹⁸F-fluciclovine and ⁶⁸Ga-PSMA-11 PET/CT. Conclusion: This case series suggests improved detection rates for ⁶⁸Ga-PSMA-11 PET/CT when compared with ¹⁸F-fluciclovine PET/CT in patients with recurrent PCa. Prospective trials designed to directly compare the two should be initiated.

Keywords: PET/CT; PSMA; biochemical recurrence; fluciclovine; prostate cancer.