Introduction:

The impact of biopsy approach on the detection rate of prostate cancer (PCa) is an active area of investigation. While recent evidence suggests higher cancer detection rates for targeted biopsies using a transperineal approach, the impact of lesion location remains unclear. This study aims to investigate the relative performance of transperineal (TP) MRI-targeted prostate biopsy (TBx) for the detection of clinically significant prostate cancer (csPCa) in the apex, compared to transrectal (TR) TBx.  

Methods:

A prospectively maintained database of patients who underwent MRI-guided prostate biopsy at our institution between 2016-2023 was queried for patients with MRI lesions in the apex.  Biopsies were performed using the UroNav MRI/ultrasound fusion biopsy system using an endfire ultrasound probe. Overall cancer detection rate, as well as rate of Gleason grade group (GG) ≥2 and GG≥3, were compared on a per-lesion basis between patients undergoing TP-TBx and patients undergoing TR-TBx. Clinical factors including PSA levels, prostate volume, and the location of the lesion in the apex were assessed using two-sample t-tests and chi-squared tests, and PIRADS scores were compared between groups using the Kruskal-Wallis test. To account for patients who underwent both TP-TBx and TR-TBx, chi-squared tests were conducted to compare the diagnoses for the same patient cohort.

Results:

Between 2016-2023, 1034 apical prostate lesion biopsies were identified, of which 159 were TP-TBx and 875 were TR-TBx (Table 1). A univariate analysis of pre-biopsy PSA, prostate volume and PIRADS demonstrated no statistically significant difference between the TP-TBx and TR-TBx groups. The rate of ≥GG2 cancers diagnosed was statistically greater for TP-TBx vs TR-TBx (44.26% vs 35.66%, p =0.03). The overall cancer detection rate (CDR) and CDR of cancers ≥ GG 3 were not statistically different between biopsy types. Amongst the sub cohort with available zonal delineation (n = 764), there was a higher CDR of GG>2 cancers in the peripheral zone, but not transition zone (Table 2). Among a subset of patients who underwent TR biopsy followed by TP (n= 34), 35.29% were upgraded on TP biopsy, while 0% of patients who underwent TR after TP biopsy (n= 5) were upgraded on TR biopsy. 

Conclusion:

In this analysis, targeted transperineal biopsy was associated with higher GG≥2 detection rate compared to transrectal biopsy for apical lesions. Prospective studies are warranted to validate transperineal biopsy as a potentially superior approach for prostate cancer detection in apical lesions in the MRI era.   

Funding: N/A