Introduction:

There is high level evidence showing the addition of MRI to the diagnostic pathway for prostate cancer improves the detection rate of clinically significant (CS) disease at time of biopsy. However, the majority of landmark studies only included patients who received prostate biopsies via transrectal (TR) approach. It is well known that transperineal (TP) approach is now preferred over TR approach due to decreased risk post-biopsy infection/sepsis. In this study, we sought to compare the impact of pre-biopsy MRI on prostate cancer detection rates when using TR vs. TP approach.

Methods:

Our institutional database was queried for all patients who underwent prostate biopsy from 2018 through 2022. Patients were then stratified by biopsy approach (TR vs. TP) and MRI status prior to biopsy. Patients were excluded from this study if they had previous diagnosis of prostate cancer or received prostate biopsy prior to referral. Patients who had a positive lesion on MRI (PIRADS >/= 3) underwent combined MRI/TRUS fusion plus systematic biopsy. Patients with a negative MRI (PIRADS < 3) or patients without pre-biopsy MRI underwent systematic biopsy only. CS cancer (defined as Gleason Grade Group >/= 2) detection rates were compared amongst groups with p-values < 0.05 considered to be statistically significant. 

Results:

We identified 318 biopsy naïve patients with an elevated PSA who were referred for biopsy. Median age and PSAD was 66 (IQR 60-70) and 0.16 ng/mL² (IQR 0.10-0.31), respectively. Overall, 51.3% (163/318) of patient received MRI prior to biopsy, with 50.6% (161/318) and 49.4% (157/318) undergoing TR and TP biopsies, respectively. PSAD of TR and TP cohorts were 0.14 ng/mL² (0.09-0.28) and 0.17 ng/mL² (IQR 0.11-0.32), repectively. There was a significantly increased CS cancer detection rate for patients who received MRI prior to TR biopsy (19/26) compared with those who did not (50/135) receive MRI prior (73.1% vs. 37.0%, p=0.001). There was no significant difference in CS cancer detection rates for patients who received MRI prior to TP biopsy (96/137) when compared with those who did not (12/20) receive MRI (70.1% vs. 60%, p=0.516).

Conclusion:

The addition of pre-biopsy MRI improves cancer detection rates for clinically significant disease when utilizing the transrectal approach. However, the same increase in cancer detection rates was not seen for patients who received MRI prior to transperineal biopsy. It is hypothesized that the transperineal systematic biopsy provides a more thorough sample of the prostate, especially for the anterior gland, therefore potentially limiting the additive benefit of MRI when compared with transrectal biopsy.

Funding: N/A