Primary Staging of Prostate Cancer Patients with [¹⁸F]PSMA-1007 PET/CT Compared with [⁶⁸Ga]Ga-PSMA-11 PET/CT

Hybrid imaging with prostate-specific membrane antigen (PSMA) is gaining importance as an increasingly meaningful tool for prostate cancer (PC) diagnostics and as a guide for therapy decisions. This study aims to investigate and compare the performance of [¹⁸F]PSMA-1007 (¹⁸F-PSMA) and [⁶⁸Ga]Ga-PSMA-11 positron emission tomography/computed tomography (⁶⁸Ga-PSMA) in the initial staging of PC patients.

The data of 88 biopsy-proven patients were retrospectively evaluated. PSMA-avid lesions were compared with the histopathologic Gleason Score (GS) for prostate biopsies, and the results were plotted by receiver operating characteristic (ROC)-curve. Optimal maximum standardized uptake value (SUV_max) cut-off values were rated using the Youden index.

¹⁸F-PSMA was able to distinguish GS ≤ 7a from ≥7b with a sensitivity of 62%, specificity of 85%, positive predictive value (PPV) of 92%, and accuracy of 67% for a SUV_max of 8.95, whereas sensitivity was 54%, specificity 91%, PPV 93%, and accuracy 66% for ⁶⁸Ga-PSMA (SUV_max 8.7).

Both methods demonstrated a high concordance of detected PSMA-avid lesions with histopathologically proven PC. ¹⁸F-PSMA and ⁶⁸Ga-PSMA are both suitable for the characterization of primary PC with a comparable correlation of PSMA-avid lesions with GS. Neither method showed a superior advantage. Our calculated SUV_max thresholds may represent valuable parameters in clinical use to distinguish clinically significant PC (csPC) from non-csPC.