A Comparative Study on the Diagnostic Efficacy and Safety of Ultrasound-Guided Transperineal and Transrectal Prostate Needle Biopsy

Abstract

Objective: To compare the diagnostic efficacy between the transperineal and the transrectal prostate needle biopsy as the initial biopsy strategy for detection of prostate cancer.

Methods: A total of 179 patients with PSA of 2.5 - 20 ng/mL who underwent initial prostate needle biopsy were included. One hundred eight (108) patients underwent transrectal prostate needle biopsy (TRUS-BX) from March to December 2014, while 71 patients underwent transperineal prostate needle biopsy (TP-BX) from January 2015 - August 2016. Descriptive statistics including mean, median and percentage were used for the patient demographics. Student's t-test was used to compare continuous variables between the two groups. X2 or Fisher's exact probability tests were used for categorical variables.

Results: The mean age of the patients who underwent the TP-BX and TRUS-BX were 66.10 years and 62 years respectively (p = 0.0003). The mean prostate volumes were 44.10 mL and 42.39 mL (p=0.5405), while the mean PSA were 9.51 ng/mL and 9.21 ng/ml (p = 0.6096) for the TP-BX and TRUS-BX, respectively. The TP-BX provided a greater overall cancer detection rate of 63.38% (45/ 71) compared to 35.19% (38/108) obtained from the TRUS-BX (p <0.0001). Detection of clinically significant cancer, defined as Gleason score of 7 or higher was likewise greater in the TP-BX compared to the TRUS-BX (77.78% vs 55.26%; p = 0.029). Among patients with PSA values of 2.5 ng/mL - 10 ng/mL, cancer detection was significantly higher in the TP-BX group (59.09% vs 31.11% p value = 0.002). Cancer detection rates in patients with PSA 10 ng/mL - 20 ng/mL were comparable in between the two groups (70.37% vs 55.56% p value = 0.309). Of the patients who had cancer in the TP-BX group, 77.77% (35/45) involved the anterior sector, 60% (27/45) the middle sector and 48.89% (22/45) the posterior sector. Thirteen out of the 35 cancers (37.14%) detected in the TP-BX group involved exclusively the anterior sector. The most common complication was hematuria at 35.21% for TP-BX and 50% for TRUS-BX. Complications that occurred exclusively for TRUS-BX included fever (2.78%) and 1 case (0.93%) of septicemia requiring hospitalization and parenteral antibiotics. Minor perineal bruising occurred exclusively in 8.45% of the patients who underwent TP-BX.

Conclusion: The transperineal prostate needle biopsy should be considered as the initial biopsy strategy for detection of prostate cancer. The manifested advantages are the following: a) The overall cancer detection rate is significantly higher, b) The detection rate of clinically significant cancer is significantly greater, c) It provides a far more superior detection of exclusive anterior zone cancers which are often under detected or undetected with the current standard TRUS-BX and d) Complications are comparable, if not fewer than the current standard TRUS-BX.