Abstract: PD43-03
Sources of Funding: none

Introduction

Multiparametric MRI (mp-MRI) is a non-invasive imaging technique that is increasingly used to stratify patients and lesions according to suspicion and risk of having significant prostate cancer (sPCa). Whereas, high suspicious findings on mp-MRI often appear to be PCa, a low-suspicious mp-MRI is assumed to predict the absence of sPCa. However, the clinical outcome after a low-suspicious mp-MRI or benign mp-MRI targeted biopsies of a suspicious lesion in a longer term is uncertain. The objective was to assess the clinical impact and the time-varying risk of being diagnosed with sPCa following either a low-suspicious mp-MRI or benign mp-MRI targeted biopsies (mp-MRI-bx) in men with prior negative transrectal ultrasound biopsies (TRUS-bx).

Methods

289 patients were included and underwent mp-MRI followed by re-TRUS-bx and mp-MRI-bx of suspicious lesions at baseline. Of these, 194 patients had either a low suspicious mp-MRI or benign mp-MRI-bx and were selected for this analysis. Men diagnosed with PCa by re-TRUS-bx were classified as mp-MRI false-negative. Men without cancer were followed for at least three years to assess how many had another re-biopsy and a subsequent diagnosis of PCa within follow-up (see flow diagram). The negative predictive values (NPV) of mp-MRI and mp-MRI-bx for ruling out any PCa, significant grade (Gleason score≥7) PCa and clinical sPCa were calculated.

Results

PCa was detected in 38/194 (20%) patients during the entire follow-up period of median 44 (range 36-59) months. The overall NVP of mp-MRI and mp-MRI-bx to rule out any PCa and significant grade PCa was 80% (156/194) and 95% (185/194), respectively. In addition, the NPV of clinical sPCa was 88% (170/194) caused by 15 patients with Gleason score 6 cancer having a PSA-density > 0.15 ng/ml/cc. No patients with low suspicious mp-MRI features had significant grade PCa detected

Conclusions

A low suspicious mp-MRI in patients with previous negative TRUS-bx has a high NPV for ruling out sPCa in a longer term. Thus, immediate repeated biopsies have only diminutive clinical impact and could be avoided even in men with persistent elevated PSA-levels.

Funding

none