To compare the correlation of transition zone prostate-specific antigen density (TZPSAD) versus whole gland (WG) density (PSAD) with Gleason score.
In this single-center, retrospective cohort study, men undergoing MRI of the prostate in 2015 and 2016 who had a transperineal template saturation biopsy within 6 months of MRI were included (n = 178; median age 64 y, interquartile range [IQR] 58-68 y; PSA 6. 6 ng/ml, 4.6-9.7 ng/ml). The WG and TZ were segmented voxel-wise on T2-weighted transverse planes. The volumes and corresponding PSA-densities were calculated. Correlations with the Gleason score were assessed with Spearman’s rho. Optimal thresholds of the PSA densities were computed using the Youden Index of the receiver-operating-characteristics curve. A p-value of ≤ 0.05 was considered statistically significant.
Median WG volume was 45 ml (IQR: 33.9-58.7 ml, range: 17.2-165.3 ml), median volume of the TZ was 27.3 ml (IQR: 19.2-39.3 ml, range: 9.0-141.1 ml). Both PSA density values, PSAD and TZPSAD, correlated significantly with the Gleason score: The PSAD (rho = 0.39) showed significantly weaker correlation than the TZPSAD (rho = 0.44, p = 0.05). ROC analysis revealed an ideal cut-off of 0.15 ng/ml2 for PSAD (95%-CI: 0.09-0.16 ng/ml2) and 0.22 ng/ml2 for the TZPSAD (0.15-0.32 ng/ml2) for discrimination between Gleason 3 + 4 and 4 + 3.
The TZPSAD exhibited a stronger correlation with cancer dedifferentiation than PSAD and may thus be a better surrogate marker for cancer aggressiveness than PSAD. Moreover, the TZPSAD threshold of 0.22 ng/ml2 may help in risk stratification of men with suspected PCa.
European journal of radiology. 2019 Sep 07 [Epub ahead of print]
Aurelia F Schneider, Daniel Stocker, Andreas M Hötker, Daniel Eberli, Niels J Rupp, Olivio F Donati, Anton S Becker
Institute of Diagnostic and Interventional Radiology, University Hospital of Zurich, Switzerland., Department of Urology, University Hospital of Zurich, Switzerland., Department of Pathology and Molecular Pathology, University Hospital of Zurich, Switzerland., Institute of Diagnostic and Interventional Radiology, University Hospital of Zurich, Switzerland. Electronic address: .