Cancer core distribution in patients diagnosed by extended transperineal prostate biopsy.

OBJECTIVES To perform systemic 22-core transperineal ultrasound-guided template prostate biopsies in patients with previous negative transrectal ultrasound-guided prostate biopsy findings and evaluate the cancer core distribution. METHODS Between April 2001 and December 2003, 128 men underwent systemic ultrasound-guided biopsy using the transperineal template technique. All patients had undergone at least one previous set of biopsies. Prostate biopsy was performed transperineally using an 18-gauge biopsy needle driven by a spring-loaded device. Four biopsies were obtained anterior to posterior from each of four coronal planes in the mid-region, and three biopsies were obtained anterior to posterior from each of two coronal planes in the apical region. RESULTS Of the 128 patients, 29 (22.7%) had cancer according to an extended transperineal biopsy. Patients with prostate cancer had significantly greater prostate-specific antigen (PSA) levels (11.4 versus 7.6 ng/mL, P = 0.0125), smaller transition zone volumes (12.7 versus 21.2 cm3, P = 0.0012), smaller prostate glands (31.5 versus 44.0 cm3, P = 0.0015), and greater PSA density (0.36 versus 0.19 ng/mL/cm3, P < 0.0001). The cancer core rates in the mid and apical parts of the anterior region (5.3% and 8.0%) were significantly greater than in the mid and apical parts of the posterior region (3.3% and 3.6%, P = 0.0297 and P = 0.0132, respectively). CONCLUSIONS The results of our study have shown that transperineal approaches are appropriate for sampling from the anterior half of the prostate gland. In patients in whom the diagnosis of prostate cancer is suspected, we believe that systemic 22-core transperineal ultrasound-guided template prostate biopsy might be the next optional diagnostic step after an initial negative prostate biopsy.