The following is a summary of “MRI vs Transrectal Ultrasound to Estimate Prostate Volume and PSAD: Impact on Prostate Cancer Detection,” published in the JANUARY 2023 issue of Urology by Choe, et al.

For a study, researchers sought to assess prostatic volume, prostate-specific antigen density (PSAD), and the ensuing effect on prostate cancer (PCa) detection using transrectal ultrasonography (TRUS) and multiparametric magnetic resonance imaging (mpMRI).

Between 2015 and 2020, patients who underwent mpMRI before having a prostate biopsy guided by mpMRI-TRUS fusion were found. Volume and the computed PSAD using mpMRI and TRUS were compared. Using linear regression (interaction by volume quartile), logistic regression, and receiver operating characteristic analysis, associations between the presence of any PCa and clinically significant PCa (csPCa; Gleason ≥3 + 4) were assessed.

In 640 males, TRUS underestimated prostate volume compared to mpMRI (median 49.2 cc vs. 54.1 cc), with 8% lower volume per cc up to 77.5 cc (first-third quartile) and 39% lower volume every additional cc above 77.5 cc (fourth quartile). Compared to surgical pathology, mpMRI had a stronger TRUS correlation coefficient for men with radical prostatectomy (0.913 vs. 0.878). For detecting any PCa or csPCa, mpMRI PSAD exhibited marginally better odds compared to TRUS PSAD (OR 2.94 and OR 2.78, both P< .001) than TRUS PSAD (OR 4.20 and OR 4.02, both P< .001). 

AUC improvements were not significant for csPCa (0.732 vs. 0.722, P =.20) and borderline significant for mpMRI vs. TRUS PSAD for any PCa. PSAD was not linked to the identification of PCa in prostates smaller than 77.5cc.

Compared to mpMRI, TRUS understated prostatic volume. Compared to TRUS, PSAD based on mpMRI may be more effective at detecting PCa; nevertheless, the utility of PSAD may be constrained for bigger prostates.

Reference: goldjournal.net/article/S0090-4295(22)00806-8/fulltext