Transperineal template-guided saturation biopsy using a modified technique: outcome of 270 cases requiring repeat prostate biopsy.

OBJECTIVES: To determine the incidence of prostate cancer (PCa), and pathological grade and location of PCa, using a modified transperineal template-guided saturation biopsy (TTSB). To compare the acute urinary retention (AUR) rate found using modified TTSB with that of published reports. PATIENTS AND METHODS: A total of 270 consecutive patients with persistent clinical suspicion of PCa, despite a median (range) of 2 (1-6) sets of negative transrectal ultrasonography-guided biopsies, were enrolled and prospectively studied. All underwent modified TTSB avoiding the peri-urethral area at the base of the prostate under general anaesthesia. Statistical analysis was performed using binary logistic regression to determine the prebiopsy predictors of PCa and AUR. RESULTS: The median (range) patient age was 64 (43-85) years, with a median (range) prostate-specific antigen (PSA) of 10 (1-114) ng/mL and median (range) prostate volume of 45 (17-106) mL. A mean (range) of 28 (16-43) cores were taken at modified TTSB. Prostate cancer was diagnosed in 54.8% (Gleason scores 6 in 27.7%, 7 in 43.2%, 8-10 in 29.1% of patients). The anterior third only was involved in 21%, the middle third in 6.8% and the posterior third in 8.7% of positive cases, although in 75% of positive cases there was some anterior involvement. Comparing uniquely anterior tumours with the 15.5% found uniquely in either the middle or posterior thirds, there was no significant difference between number of positive cores (2 vs 1, P = 0.091), maximum percentage core involvement (30 vs 17.5%, P = 0.315) and maximum tumour length (3.5 vs 2 mm, P = 0.092). Fourteen patients (5.2%) developed AUR. On multivariate analysis, PSA density (PSAD) and pre-TTSB PSA predicted PCa diagnosis, whilst prostate volume, prebiopsy PSA and PSAD predicted AUR. CONCLUSIONS: Modified TTSB has a high cancer yield, especially in the anterior region, in patients with previously negative histology but onward suspicion of PCa. The modified TTSB technique provides a low risk of AUR without compromising cancer yield.