Pirads 3 lesions characterised by mp-mri of the prostate correspond with an intermediate to high risk of clinically significant prostate cancer on whole specimen histopathology-a retrospective review of 42 cases

Abstract

Objective: To assess whether lesions characterised by the prostate image reporting and data system (PIRADS) following 3T multiparametric magnetic resonance imaging (MRI) of the prostate correspond to clinically significant prostate cancers when assessed by histology following radical robotic prostatectomy (RRP). Method: A retrospective analysis of consecutive patients undergoing mpMRI of the prostate for suspicion of prostate cancer between October 2012 to April 2014. Demographic, clinical, MRI and histological data was examined. All patients underwent a multiparametric 3T-MRI (T2 and diffusionweighted imaging). Radiologists characterized lesions as per PIRADS criteria. We compared MRI results to corresponding histopathology obtained from the database of a specialised uro-pathologist. Patient characteristics assessed included PIRADS score and location of tumour on mpMRI, tumour volume on histopathology, prostate weight, Gleason grade, evidence of perineural invasion and pathological stage. Grade and location of MRI reported lesions were directly compared with whole specimen histopathology to determine correlation. Clinically significant disease was defined as per Epstein's Criteria. [1] Results: Overall 42 patients had PIRADS 3 lesions of which all underwent RRP and histological analysis. The mean age was 63 years. The median PSA was 6.3 ng/ml and median prostate weight 45.87g. Of the PIRADS 3 lesions, 30.9% were Gleason 3+3 = 6; 50% 3+4 = 7; 11.9% Gleason 4+3 = 7 and 7.2% were Gleason ≥8. 11 of the 42 had a tumour volume ≥ 0.5CC and 31 had tumours ≥0.5CC in volume. Importantly, 23 (54.8%) of the 42 patients were found to have clinically significant lesions with 7(16.6%) having Gleason 3+4 = 7 disease and 4 (9.5%) with 4+3 = 7 and 2 (4.8%) with Gleason ≥8. Conclusion: We have demonstrated that prostate lesions characterized by 3T mpMRI examination of the prostate as PIRADS 3, in accordance with the current prevalent scoring systems, is associated with an intermediate to high risk of significant prostate cancer being present.L617436398 <br />