18F-Fluciclovine PET/CT for the Detection of Prostate Cancer Relapse

In recent years, a new PET compound (anti-3-(18)F-FACBC or (18)F-fluciclovine) was tested for the detection of prostate cancer relapse. Despite very promising results, only preliminary data were available with regard to the comparison to (11)C-choline. The aim of this study was to compare the detection rate of (18)F-FACBC and (11)C-choline in patients presenting a biochemical relapse.Fifty patients radically treated for prostate cancer and presenting with rising prostate-specific antigen (PSA) levels were consecutively and prospectively enrolled. All the patients were out of hormonal therapy and underwent both (11)C-choline PET/CT and (18)F-fluciclovine PET/CT within 1 week. The results were compared in terms of detection rate on a patient and lesion basis. Furthermore, a more detailed analysis regarding local, lymph node, and bone relapse was performed.On a patient-based analysis, (18)F-fluciclovine detection turned out to be significantly superior to (11)C-choline (P < 0.000001). This result was also true on lesion, lymph node, bone lesion, and local relapse analysis (P < 0.0001 in all the cases). There was no significant difference in terms of target to background of positive lesions between (11)C-choline and (18)F-fluciclovine. When the patients were divided into groups with different PSA levels, (18)F-fluciclovine had a superior detection rate for low, intermediate, and high PSA levels.In our experimental conditions, (18)F-fluciclovine provided a statistically significant better performance in terms of lesion detection rate as compared with (11)C-choline. However, more studies are required to evaluate the clinical significance of these results in terms of sensitivity, specificity, and accuracy.