Transperineal Biopsy Under Ultrasound Guidance For Prostate Cancer Detection as an Initial and as a Repeat Biopsy Strategy

Abstract

Objective: To present the authors’ experience on transperineal prostate sector biopsy (TPSB) in detecting prostate cancer, in identifying both low Gleason prostate cancers as well as clinically significant prostate cancer (Gleason 7 and higher), and in determining anatomical distributions of prostate cancer in the both initial and repeat biopsy settings.

Methods: All patients from June 2014 to September 2016 who underwent TPSB, as initial biopsy or repeat biopsy after previous negative transrectal ultrasound-guided biopsy (TRUSPNB) were included. Data for each patient were collected prospectively and subjected to statistical analysis. T test was used for continuous variables while Chi square test or Fisher exact test was used for categorical variables. Multiple logistic regression models were used to identify factors predictive of a positive biopsy result.

Results: A total 130 patients were included in the study, 73 had TPSB as initial biopsy and 57 as repeat biopsy after previous negative TRUSPNB. The mean patient age of the Initial Biopsy Group (IBG) was 66 years while the mean age for the Repeat Biopsy Group (RBG) was 68 years. The IBG had a lower mean serum PSA level (9.07 ng/mL for IBG and 9.59 ng/ml for RBG) and smaller prostate volumes (42.9 mL for the IBG and 44.3ml for the RBG). Prostate cancer was detected in 65.8% (48/ 73) of the IBG and 40.4% (23/57) of RBG, of which 77.1% (37/48) and 73.9% (17/23) respectively, were clinically significant, defined as a Gleason score of ≥7. Of the cancers detected in IBG , 29.2% (14/48) exclusively involved the anterior sector (based on the Ginsburg Study Group's biopsy map), while 30.4% (7/23) were con?ned exclusively within the anterior sector for the RBG. Increasing PSA level and lower prostate volumes were predictive of cancer detection in RBG, while only increasing PSA level was predictive of a positive result in IBG.

Conclusion: Transperineal prostate sector biopsy demonstrated a high prostate cancer detection rate for both the initial and repeat biopsy settings. Likewise it provides for excellent sampling of the anterior region of the prostate, as it affords a more accurate sampling of the prostate gland based on a preplanned map and template to sample areas of interests. Similarly, it detects a high proportion of patients with clinically significant prostate cancer.This technique should therefore be highly considered as a first line option for all patients in whom a prostate biopsy is warranted.