PI-RADS 2.1 is valid for detecting prostate cancer in bpMRI in an Irish population

Magnetic resonance imaging (MR) of the prostate is an important part of the diagnostic pathway for patients with suspected prostate cancer. Current practice in many Irish centres is to perform biparametric MRI (bpMRI) incorporating T2- and diffusion-weighted imaging, and interpret it using the latest version of the American College of Radiology Prostate Imaging Reporting and Data System (PI-RADS), version 2.1. No study has yet reported on the use of bp-MRI and PI-RADS 2.1 in the investigation of prostate cancer investigation in the Irish healthcare setting.

We aimed to review one year of practice at our regional tertiary prostate cancer referral centre and compare diagnostic yield with international standards.

We identified all patients who had undergone prostate biopsy at our institution in 2023 and extracted pre-biopsy MRI results for each patient, comparing MRI results with biopsy reports.

We identified 328 patients in the study period who underwent prostate biopsy and pre-biopsy MRI. 182 of these had a pathological diagnosis of clinically significant prostate cancer (csPCa), defined as Gleason score of 7 or higher. Of these, 167 (92%) had a PI-RADS score of 3 or above, meaning at least equivocal for the presence of csPCA. Cancer detection rates were 31%, 54% and 96% for PI-RADS three, four and five lesions respectively. We demonstrated a sensitivity of 92% and specificity of 49% for detection of csPCa, closely aligned with international datasets.

The use and performance of bpMRI and PI-RADS 2.1 at our Irish tertiary urological centre is in line with international datasets. These have a key role in the diagnostic pathway of prostate cancer in Ireland.