OBJECTIVES
We investigated the efficacy of transperineal template-guided mapping biopsy (TTMB) for patients on active surveillance (AS) or those with previous negative transrectal ultrasound-guided biopsy (TRUS-Bx).
METHODS
We retrospectively analyzed 99 patients on AS and 60 patients with previous negative TRUS-Bx, which is a total of 159 patients who underwent TTMB from May 2017 to January 2019. Cancer location was analyzed with focus on the anterior and apex lesions of the prostate after TTMB. Multiparametric magnetic resonance imaging was performed before TTMB. Cancer location after TTMB in 138 patients, excluding 21 patients who were not eligible for analysis (4 patients on AS and 17 patients with previous negative TRUS-Bx) was compared with Prostate Imaging-Reporting and Data System version 2 (PI-RADSTM v2) score. Factors that may affect detecting cancer after TTMB with previous negative TRUS-Bx was analyzed using a logistic regression model.
RESULTS
In AS patients, 29 patients (29.3%) exhibited an upgrade in Gleason score (GS) after TTMB. Among them, 22 patients (75.9%) showed at the anterior or apex lesions. In patients with previous negative TRUS-Bx, 18 patients (30.0%) were diagnosed with prostate cancer. Among them, 13 patients (72.2%) exhibited cancer at the anterior or apex lesion. Among the 25 AS patients with PI-RADSTM score 1-2, 5 patients (20.0%) showed an upgrade in GS. Among the 26 patients with previous negative TRUS-Bx and PI-RADSTM score 1-2, 6 patients (23.1%) had cancer. In multivariate regression model, prostate volume (OR 0.951) was identified as the predictor for a positive biopsy result after TTMB with previous negative TRUS-Bx.
CONCLUSIONS
TTMB is efficient for patients on AS in the detection of upgraded cancer located in anterior or apex or those with previous negative TRUS-Bx in the detection of anterior or apex cancer. In PI-RADSTM score 1-2, a substantial proportion of patients after experienced upgrade in GS on AS patients or cancer detection on previous negative TRUS-Bx. Moreover, we identified prostate volume is the independent predictor for a positive biopsy result after TTMB with previous negative TRUS-Bx.