MRI predicts prostatic urethral involvement in men undergoing radical prostatectomy: implications for cryo-ablation of localized prostate cancer.

To determine whether multi-parametric magnetic resonance imaging (mpMRI) can reliably predict proximity of prostate cancer to the prostatic urethra in a contemporary series of men undergoing radical prostatectomy (RP) at two academic centers.

Clinical characteristics of consecutive men undergoing pre-operative mpMRI prior to RP and whole-mount axial serial step-sectioned pathology examination at two academic centers between Jun 2016 and Oct 2018 were analyzed retrospectively. Every tumor was characterized by its pathologic minimum distance to the prostatic urethral lumen (pMDUL). Only the cancer closest to the urethra represented the prostatic urethral index lesion. The radiologic minimum distance of the index lesion to the prostatic urethral lumen was measured and noted as ≤ 5 mm versus  > 5 mm. The sensitivity, specificity, positive and negative predicting values (PPV and NPV) and area under the receivers operating characteristics curve (AUC) were calculated for performance of mpMRI for predicting pMDUL ≤ 5 mm.

Of the 163 surgical specimens examined, 112 (69%) exhibited a pMDUL ≤ 5 mm. These men had significantly higher grade group (GG) and advanced pathological and clinical stage. The rates of high PI-RADS score and presence of gross extracapsular extension were also significantly greater for the group with pMDUL ≤ 5 mm. The AUC, sensitivity, specificity, PPV, and NPV were 0.641, 51.8, 76.5, 82.9, and 42.4%, respectively, for mpMRI to predict pMDUL < 5 mm.

Nearly 70% of men undergoing RP present with tumor within 5 mm of the prostatic urethra. These tumors present higher risk characteristics, and mpMRI exhibited moderate performance and high PPV in their pre-operative detection. Physicians performing partial gland ablation should take these results into consideration during treatment selection and planning.

World journal of urology. 2021 Feb 22 [Epub ahead of print]

Ezequiel Becher, Akash Sali, Andre Abreu, Tsuyoshi Iwata, Angela Tong, Fang-Ming Deng, Atsuko Iwata, Chhavi Gupta, Inderbir Gill, Manju Aron, Suzanne Palmer, Herbert Lepor

Department of Urology, NYU Langone Health, 222 E41st St, 12th floor, New York, NY, 10017, USA. ., Department of Urology, Keck School of Medicine, USC Institute of Urology and Catherine and Joseph Aresty, University of Southern California, Los Angeles, CA, USA., Department of Radiology, NYU Langone Health, New York, NY, USA., Department of Pathology, NYU Langone Health, New York, NY, USA., Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA., Department of Radiology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA., Department of Urology, NYU Langone Health, 222 E41st St, 12th floor, New York, NY, 10017, USA.

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