Introduction

Magnetic resonance imaging-transrectal ultrasound (MRI-TRUS) fusion-guided prostate biopsy has been shown to increase the detection of clinically significant prostate cancer (PCa) by targeting specific lesions at biopsy. Our objective was to evaluate the accuracy of MRI-TRUS fusion biopsy to determine final pathology at radical prostatectomy (RP) as compared to untargeted extended template TRUS-guided prostate biopsy.

Methods

From a single institution database, 2,201 patients were identified who underwent both prostate biopsy and RP between 2006 and 2016. Propensity score matching was performed with the nearest neighbor method using R-programming version 3.3.1 and a 4:1 match ratio. A total of 101 men were identified who underwent MRI-TRUS plus standard template biopsies were subsequently matched to 404 men who underwent untargeted extended template TRUS biopsy. Matched covariates included age at diagnosis, initial prostate specific antigen (PSA), race, clinical stage, total number of cores retrieved at time of biopsy, and history of prior TRUS biopsy. Continuous variables were compared using Wilcoxon rank-sum tests and categorical variables were assessed with χ2 test. The concordance of Gleason score from biopsy to RP was assessed.

Results

After propensity score matching, median age was 64 years (IQR 59.5-68.5), median PSA was 5.4 ng/mL (IQR 4.0-8.1), median prostate size was 48 grams (IQR 38.5-60), and median number of cores retrieved at time of biopsy was 15 (IQR 12-20). Of patients who received MRI-TRUS plus standard template biopsy, 67 of 99 (67.7%) showed concordant Gleason grading between biopsy and RP pathology, whereas 204 of 397 (51.4%) of extended template TRUS biopsy patients were concordant (p<0.01). Fewer MRI-TRUS plus standard template biopsy patients were either upgraded (26.3% versus 32.2%) or downgraded (6.1% versus 15.4%) from biopsy to RP (p<0.01).

Conclusions

Of men undergoing TRUS biopsy for the diagnosis of PCa, MRI-TRUS fusion plus standard template techniques have a higher concordance with final pathology at RP. Additionally, MRI-TRUS techniques demonstrated better accuracy with lower rates of upgrading and downgrading prostatectomy when compared to untargeted extended template TRUS biopsy independent of total number of cores taken.

Funding

none