To compare the diagnostic values of different diagnostic criteria of prostate specific membrane antigen (PSMA) PET/CT for primary prostate cancer (PCa).

From May 2019 to May 2021, 2-(3-(1-carboxy-5-((6-¹⁸F-fluoro-pyridine-3-carbonyl)-amino)-pentyl)-ureido)-pentanedioic acid (¹⁸F-DCFPyL) PET/CT images of 78 patients (age: (68.5±1.4) years) with clinically suspected PCa in Shanxi Bethune Hospital were retrospectively collected and blind diagnosed by the three criteria of SUV_max, PSMA reporting and data system (PSMA-RADS) score and molecular imaging PSMA (miPSMA) score. The diagnostic efficacy for PCa, the correlation between the diagnostic results and disease risk, and the consistency of the diagnostic results of the three criteria were compared. Delong test, Spearman rank correlation analysis, and intra-class correlation coefficient (ICC) were used to analyze data.

The sensitivities of SUV_max, PSMA-RADS score and miPSMA score for PCa were all 93.75%(60/64) and the specificities were 12/14, 10/14 and 12/14 respectively; AUCs of the three criteria were 0.951, 0.862 and 0.951, with no significant difference between SUV_max and miPSMA score (z=0.00, P=1.000), while there were significant differences between PSMA-RADS score and SUV_max or miPSMA score (z values: 2.71, 2.93, P values: 0.007, 0.030). There were positive correlations between the diagnostic results of the three criteria and the disease risk (International Society of Urological Pathology (ISUP) grading: r_s values: 0.66, 0.62, 0.63, all P<0.001; D′Amico grouping: r_s values: 0.67, 0.64, 0.67, all P<0.001). The diagnostic results of the three criteria were highly consistent (ICC=0.941, 95% CI: 0.903-0.967).

The SUV_max and miPSMA score have higher diagnostic efficiency and correlation of disease risk, which are more suitable for clinical application.

Prostatic neoplasms; Prostate-specific membrane antigen; Urea; Positron-emission tomography; Tomography, X-ray computed; Diagnosis, differential