Introduction: Transrectal ultrasound guided prostate biopsy has long been the diagnostic standard; however, inherent limitations along with technological advancements have paved the way for multiparametric Magnetic Resonance Imaging (MRI) and fusion biopsy to be used as diagnostic tools. Few studies have examined the learning curve associated with MRI-ultrasound (US) guided fusion biopsy, with most examining the transrectal (TR) biopsy approach. There is a paucity of data describing the learning curve using the transperineal (TP) approach. Herein, we seek to describe the learning curve associated with MRI-US TP guided fusion biopsy.
Methods: After institutional review board approval, a retrospective review was performed for consecutive men who underwent MRI-US TP fusion biopsy between June 2018 and October 2020 involving 5 different urologists. All men had an elevated prostate specific antigen (PSA) (> 4.0 ng/mL) or abnormal digital rectal exam and underwent MRI demonstrating a lesion using the Prostate Imaging Reporting and Data System (PIRADS) version 2 guidelines. All men subsequently underwent TP targeted biopsy with the KOELIS TrinityTM prostate fusion biopsy system. The overall cohort was separated into quartiles (N = 40 per group) and was also stratified by urologist and PIRADS score.
Results: A total of 160 patients underwent MRI-US TP fusion biopsy. The learning curve for overall cancer detection rate (Gleason Grade Group (GG) 1-5) was approximately 80 cases (cancer detection rate per quartile = 57.5, 50, 62.5 and 65%, p< 0.01) and was approximately 40 cases (cancer detection rate per quartile = 22.5, 40, 47.5 and 40%, p< 0.01) for clinically significant prostate cancer (csPC) (defined as Gleason GG 2-5). When stratified by urologist of varying experience and volume, there was no appreciable difference in the cancer detection rate or learning curve for csPC (p = 0.6). When stratified by PIRADS score, cancer detection rates typically stabilized after 25 cases for PIRADS 3 and 4 lesions with minimal to no learning curve for PIRADS 5 lesions (Figure 1).
Conclusions: The learning curve for csPC detection rate using the KOELIS TrinityTM prostate fusion biopsy system via a TP approach was approximately 40 cases which did not vary based on user. Lower PIRADS scores of 3-4 were associated with a longer learning curve.
.jpg)
.jpg)
