Institutional Adoption and Apprenticeship of Fusion Targeted Prostate Biopsy: Does Experience Affect the Cancer Detection Rate?

PIRADS≥4 MRI lesion: Is performing systematic biopsies still essential for detecting clinically significant prostate cancer?

INTRODUCTION

In the era of targeted prostate biopsies, the necessity of performing randomized biopsies systematically is under question. Our objective is to evaluate the rate of clinically significant prostate cancer (csPCa), defined by presence of ISUP≥2 prostate cancer, diagnosed only on randomized cores in case of a PIRADS≥4 target lesion on MRI. The secondary objective is to evaluate whether specific variables can predict the presence of undetected csPCa in targeted biopsies.

METHODS

Retrospective data on targeted biopsies performed from 2015 to 2021 in our hospital were collected. Procedures were performed with MRI/Transrectal US fusion Trinity platform from Koelis®. All the MRI images were reviewed and the targets were classified using the PIRADS V2.1 classification. Inclusion criteria comprised procedures featuring at least one PIRADS≥4 targeted lesion were included. All procedures consisted 1-4 targeted cores and 12-core systematic biopsy.

RESULTS

We included 358 patients. In 44 patients (12.3%) csPCa was exclusively detected in randomized cores. Among these cases, only 12 patients (27.2%) showed no cancer on the targeted biopsies. Merely 4 patients (9.09%) lacked csPCa-positive cores on the same side as the index lesion. Factors such as PSA, PSA density, prostate volume, and digital rectal examination showed no significant association with the presence of csPCa exclusively on randomized cores. Likewise, the size, location, and PIRADS classification of the target demonstrated no significant impact.

CONCLUSION

Our findings indicate that in 12.3% of cases, targeted biopsies alone are insufficient for detecting the presence of csPCa. As such, systematic biopsies remain necessary to date.

LEVEL OF EVIDENCE: 4

Surgeon seniority and experience have no effect on CaP detection rates using MRI/TRUS fusion-guided targeted biopsies

OBJECTIVE

To determine (i) whether urologist seniority and experience are associated with prostate cancer (CaP) and clinically significant CaP (csCaP) detection rates using magnetic resonance imaging/ultrasound (MRI/US) fusion-guided targeted biopsies, taking multiparametric magnetic resonance imaging (mpMRI) as the reference standard, and (ii) if cancer detection rates (CDR) differ across regions of the prostate using Dickinson's 27-sector map, regardless of seniority.

METHODS

We retrospectively reviewed a consecutive series of patients with suspicion of prostate cancer who underwent targeted and systematic biopsies at 1 center by 1 of 7 urologists (2 seniors and 5 juniors) between January 1, 2016 and December 31, 2021, following positive mpMRI.

RESULTS

The cohort comprised 403 patients (454 lesions) aged 67.7±6.8. The combined (junior and senior) CDR was 57% for CaP and 28% for csCaP. There were no differences in CDR between junior and senior urologists for CaP (58% vs. 55%, P = 0.538) or csCaP (29% vs. 26%, P = 0.58). A general trend was observed for the learning curve, which indicated increasing CDR with urologist experience. Across the 27 sectors, combined CDR ranged between 39% and 99% for CaP and 1% to 67% for csCaP. When grouping anterior vs. posterior sectors, there were no differences in combined CDR of CaP (64% vs. 67%, P = 0.48) and csCaP (31% vs. 38%, P = 0.19) CONCLUSIONS: Urologist seniority is not associated with CDR, urologist experience tends to improve cancer detection, and CDR does not differ between the anterior and posterior regions of the prostate.

Number of cores needed to diagnose prostate cancer during MRI targeted biopsy decreases after the learning curve

INTRODUCTION

We hypothesized that the number of cores needed to detect prostate cancer would decrease with increasing MRI-targeted biopsy (TBx) experience.

METHODS

All patients undergoing TBx at our institution from May 2017 to August 2019 were enrolled in a prospectively maintained database. Five biopsy cores were obtained from each lesion ≥3 on PI-RADS v2.0 followed by a systematic 12-core biopsy. To assess learning curve, the study population was divided into quartiles by sequential biopsies. Clinically significant prostate cancer (csPC) was defined as Gleason Grade Group 2 or higher.

RESULTS

377 patients underwent prostate biopsy (533 lesions); 233 lesions (44%) were positive for prostate cancer and 173 lesions (32%) were csPC. There was a significant decline in the number of cores required for diagnosing any cancer (P < 0.001) and csPC (P < 0.05) after the first quartile. There was no difference when stratifying by PI-RADS score or lesion volume. Within the first quartile, limiting the biopsy to 3 cores would miss 16.2% of csPC, decreasing to 6.6% after approximately 100 patients.

CONCLUSION

MRI TBx is associated with a learning curve of approximately 100 cases. Four or 5 cores should be considered during the initial experience, but thereafter, 3 cores per lesion is sufficient to detect csPC.