Comprehensive evaluation of the clinical utility of transperineal template guided mapping biopsy of prostate in the era of magnetic resonance imaging.

Abstract

55 Background: To evaluate the clinical utility of Transperineal Template guided Mapping Biopsy (TTMB) after the routine use of Magnetic Resonance Imaging (MRI) for prostate cancer in our institution. Methods: We retrospectively analyzed 208 TTMB performed at our institution from April 2013 - August 2014. Anterior cancer defined as ≥ 80% of the positive cores anterior to urethra. Clinically significant cancer detection verified at various thresholds of Maximum Cancer Core Length (MCL) – 2mm / 3mm / 4mm / 6mm ± Gleason score (GS) ≥ 3+4. We analyzed TTMB for the indications, cancer detection and correlation with TRUS, MRI and Radical Prostatectomy (RP) specimens. Results: The indications and cancer detection rates of TTMB are in the table. All the patients had MRI before TTMB and 87.7% had it prior to the initial TRUS and all target biopsies were by cognitive registration. Multivariate analysis showed higher number of TTMB cores and prior negative TRUS to predict detection of clinically significant anterior tumor. The laterality of cancer in TTMB correlated with TRUS, MRI and Radical Prostatectomy (RP) in 67.2%, 75.3% and 87.6% respectively. The Gleason upgrade from TRUS to TTMB was 19.2% and TTMB to RP was 14.8%.Clavien-Dindo grade 1 and 2 complication was noted in 40.2% and 7% patients respectively. Conclusions: Even with the routine of MRI prior to TRUS biopsy, TTMB had clinical utility and was very effective in detecting clinically significant cancers in specific clinical situations. [Table: see text]