Background: 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]PSMA1007 (18F-PSMA) and [68Ga]Ga-PSMA-11 positron emission tomography/computed tomography
(
68Ga-PSMA) in the initial staging of PC patients. Methods: 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 (SUVmax) cut-off values were rated
using the Youden index. Results: 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 SUVmax of 8.95, whereas sensitivity was 54%, specificity 91%, PPV 93%, and accuracy 66% for
68Ga-PSMA (SUVmax 8.7). Conclusions: 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 SUVmax thresholds may represent
valuable parameters in clinical use to distinguish clinically significant PC (csPC) from non-csPC