2.1

Study population

This is a prospective study where consecutive patients who underwent multiparametric magnetic resonance imaging (mpMRI) followed by TP PBx between May 2017 and January 2023 were enrolled (IRB# HS-13-00663). Inclusion criteria: patients who underwent mpMRI followed by TP PBx for I) suspicion of PCa; II) active surveillance or restaging PBx for PCa. Exclusion criteria: patients with I) prior treatment for PCa; II) any prior surgery for benign prostatic hyperplasia; III) saturation PBx; IV) those with mpMRI that did not meet Prostate Imaging Reporting and Data System (PIRADS) standards [ , ].

2.2

MRI acquisition and interpretation

The detailed MRI protocol has been described elsewhere [ , ]. The mpMRIs were evaluated according to the PIRADS versions 2.0 or 2.1, by experienced radiologists [ , ]. Prostate MRIs performed outside the institution were re-reviewed by our institutional radiologists and were included if they met PIRADS standards.

2.3

Prostate biopsy protocol

All PBx were carried out transperineally using a 3-dimensional organ-tracking elastic image-fusion system (Trinity, Koelis®, France) and 18G needle-biopsy, under local anesthesia or sedation, as previously described [ , ]. Those who underwent TP PBx under local anesthesia received only lidocaine without any analgesics or anxiolytics [ , ]. The procedures were performed using a freehand technique with a coaxial needle, without a grid template apparatus or probe-mounted needle guide [ ]. All patients underwent 12 to 14 cores templated systematic biopsies (SB), with a minimum of 2 additional targeted cores per each PIRADS 3 to 5 lesion, as described elsewhere [ , , ]. The PBx specimens were individually labeled and submitted in separate containers for uropathologist evaluation according to the International Society of Urological Pathology (ISUP) guidelines [ ].

Antibiotic prophylaxis was gradually de-escalated based on the evolving evidence supporting the safety of performing TP PBx without antibiotics [ ]. Therefore, most patients at the beginning of this series received a single prophylactic dose of Cefuroxime 500mg, while most recent biopsies were antibiotic-free [ , ]. Patients with cardiac valve disease or replacement, those immunosuppressed, and those with a history of acute prostatitis routinely received injectable Gentamicin or Ceftriaxone prior to the biopsy [ , , ].

2.4

Stepwise approach

All biopsies in this study were performed by a single urologist (ALA) who had a large experience with over 1500 MRI/TRUS fusion transrectal PBx under local anesthesia before adopting the TP PBx approach [ , , ]. It is important to note that TP PBx has been performed in the U.S. for a long time. However, TP MRI/TRUS fusion PBx is more recent, with platforms becoming available in 2017 [ , ]. As such, the availability of proctoring and/or educational materials or videos was limited. As an earlier adopter of this approach and technique in the U.S., the operator considers himself as self-taught. Therefore, the initial plan involved implementing a stepwise approach by starting with MRI/TRUS fusion TP PBx in the operating room and then transitioning to local anesthesia in clinic.

The cohort was divided into chronological quintiles (Q1 to Q5), as previously described [ ]. Most of the patients in the 1st quintile underwent TP PBx under sedation in the operating room, whereas the majority of patients in the 2nd to 5th quintiles had their biopsies performed under local anesthesia in the outpatient clinic [ , ]. Once the operator had transitioned to preferentially performing his cases under local anesthesia, the use of sedation was then based on patient preference.

2.5

Endpoints and definitions

The study’s primary endpoints were the detection of CSPCa on SB, TB, and SB plus TB among the chronological quintiles and the number of cases needed to achieve proficiency based on operative time. The secondary endpoint was the 30-day postoperative complication rates. Patients’ demographics, MRI findings, the patients’ self-assessed pain and histologic PBx characteristics were also analyzed.

Clinically significant prostate cancer (CSPCa) was defined as Grade Group ≥2. Operative time was defined as the time from when the TRUS probe was inserted to when it was removed from the patient’s rectum. Complications were recorded up to 30 days post-PBx and reported according to the Clavien-Dindo classification as previously described [ , , ]. The pain was self-assessed by the patients, only in those who underwent TP PBx under local anesthesia, using a visual analog scale (0–10) immediately after the procedure [ ].

Race and ethnicity were self-reported according to U.S. National Institutes of Health standards, as follows: Hispanic or Latino (Latino); non-Hispanic Asian (Asian), non-Hispanic Black or African American (Black), non-Hispanic White (White), and Others (Native Hawaiian or Other Pacific Islander; American Indian or Alaska Native; and those who did not report or identify as any race or ethnicity).

2.6

Statistical analysis

The statistical software package SAS version 9.4 (SAS Institute Inc., Cary, NC, USA) was used for all analyses in this study. The Wilcoxon rank sum test was used for continuous variables, and Pearson’s chi-square was used for categorical variables. Univariable and multivariable logistic and linear regressions were performed to model the dichotomous and continuous outcomes, respectively, with different periods of PBx and other predictors. The inflection point analysis was used to determine the number of cases to reach proficiency for operative time [ , ]. A 2-sided P -value of < 0.05 was considered statistically significant.