Clinical utility of transperineal template-guided mapping biopsy of the prostate after negative magnetic resonance imaging-guided transrectal biopsy.

PURPOSE: We evaluated the prostate cancer detection with transperineal template-guided mapping biopsy in patients with elevated prostate-specific antigen and negative magnetic resonance imaging (MRI)-guided biopsy.

MATERIALS AND

METHODS

Totally 75 patients underwent transperineal template-guided mapping biopsy for prior negative MRI-guided (cognitive registration) biopsy during April 2013 to August 2014. Primary objective was to report clinically significant cancer detection in this cohort of patients. Significant cancer was defined using varying thresholds of MCL or Gleason grade 3+4 or greater or both. Cancers with more than 80% of positive core length anterior to the level of urethra were termed anterior zone cancer. Secondary objective was to evaluate the potential clinical and radiological predictors for significant cancer detection.

RESULTS

The mean age was 61.6 ± 6.5 years and median prostate-specific antigen was 10.4 ng/dl (7.9-18) with a mean MRI target size of 7.2mm (4-11). Transperineal template-guided mapping biopsy identified cancer in 36% (27/75) patients and 66.6% (18/27) of them were anterior zone cancers. The rates of detection of clinically significant and insignificant cancer according to the several definitions used range from 22.7% to 30.7% and 5.3% to 13.3%, respectively. Multivariate analysis did not identify any predictors for finding clinically significant and anterior cancers in this group of patients.

CONCLUSION

Transperineal template-guided mapping biopsy appears to be an excellent biopsy protocol for downstream management following negative MRI-guided biopsy. Most of the cancers detected were predominantly anterior tumors.