The present study assessed the role of [18F]Fluciclovine PET/CT in detecting early recurrent prostate cancer (PCa) and its influence on treatment decisions. We retrospectively reviewed 58 [18F]Fluciclovine PET/CT scans performed for suspected early recurrence. Detection rates (DR) and semiquantitative parameters were analyzed in relation to biochemical and clinical–pathological characteristics. Clinical follow-up served as the reference standard to determine sensitivity, specificity, accuracy, and predictive values (PPV and NPV). The overall DR was 66%, with lesion-specific rates of 53% in the prostate/prostate bed, 28% in lymph nodes, and 7% in bone. Higher PSA levels were associated with increased detection (p = 0.009), and a PSA threshold of 0.45 ng/mL was identified as optimal. Semiquantitative indices, including SUVmax and SUVmean, were useful in differentiating malignant from benign lesions. The imaging modality achieved a sensitivity of 87.1%, specificity of 80.0%, PPV of 87.1%, NPV of 80.0%, and an overall accuracy of 84.3%. Based on PET/CT findings, therapeutic management was altered in 51% of cases. These results highlight [18F]Fluciclovine PET/CT as a reliable approach for early restaging of PCa, particularly for local recurrence, and suggest that semiquantitative analysis may further improve diagnostic specificity.
