Comparison Between Cu-PSMA-617 PET/CT and F-Choline PET/CT Imaging in Early Diagnosis of Prostate Cancer Biochemical Recurrence.

PURPOSE

To evaluate the diagnostic performance of Cu-PSMA-617 positron emission tomography (PET) with computed tomography (CT) for restaging prostate cancer after biochemical recurrence (BCR) and to compare it with F-choline PET/CT in a per-patient analysis.

PATIENTS AND METHODS

An observational study was performed of 43 patients with BCR after laparoscopic radical prostatectomy who underwent Cu-PSMA-617 PET/CT and subsequently F-choline PET/CT for restaging. The detection rates (DR) of Cu-PSMA-617 PET/CT and of F-choline PET/CT were calculated by standardized maximum uptake value (SUV) at 4 hours and SUV at 1 hour as reference, respectively. Furthermore, univariate logistic regression analysis was carried out to identify independent predictive factors of positivity with Cu-PSMA-617 PET/CT.

RESULTS

An overall positivity with Cu-PSMA-617 PET/CT was found in 32 patients (74.4%) versus 19 (44.2%) with F-choline PET/CT. Specifically, after stratifying for prostate-specific antigen (PSA) values, we found a good performance of Cu-PSMA-617 PET/CT at low PSA levels compared to F-choline PET/CT, with a DR of 57.1% versus 14.3% for PSA 0.2-0.5 ng/mL (P = .031), and of 60% versus 30% with PSA 0.5-1 ng/mL. At univariate binary logistic regression analysis, PSA level was the only independent predictor of Cu-PSMA-617 PET/CT positivity. No significant difference in terms of DR for both Cu-PSMA-617 PET/CT and F-choline PET/CT was found according to different Gleason score subgroups.

CONCLUSION

In our study cohort, a better performance was observed for Cu-PSMA-617 PET/CT compared to F-choline PET/CT in restaging after BCR, especially in patients with low PSA values.