Impact of 5-alpha reductase inhibitors on pre-biopsy MRI interpretation: effects on PI-RADS assessment and local staging

Arianna Tumminello¹, Giuseppe Reitano¹, Elisa Tonet¹, Giovanni Basso¹, Felice Crocetto², Iliana Bednarova³, Francesca Caumo³, Matteo Todisco⁴, Alberto Lauro⁴, Carmelo Lacognata⁴, Francesca Galuppini⁵, Giorgio De Conti⁴, Giovanni Betto¹, Massimo Iafrate¹, Giacomo Novara¹, Fabrizio Dal Moro¹, Fabio Zattoni^1,*
1 Urology Clinic, Department of Surgery, Oncology and Gastroenterology (DISCOG), University of Padova, Padova, Italy
2 Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples “Federico II”, Naples, Italy
3 Radiology Unit, Veneto Institute of Oncology IOV-IRCCS, Padua, Italy
4 Radiology Unit, Department of Radiology, University Hospital of Padua, Padua, Italy
5 Surgical Pathology & Cytopathology Unit, Department of Medicine (DIMED), University of Padova, Padova, Italy
* Corresponding Author: Fabio Zattoni. Email: email
(This article belongs to the Special Issue: Advancing Early Detection of Prostate Cancer: Innovations, Challenges, and Future Directions)

Canadian Journal of Urology https://doi.org/10.32604/cju.2026.073468

Received 18 September 2025; Accepted 26 March 2026; Published online 13 May 2026

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Abstract

5-alpha reductase inhibitors (5-ARIs) are widely prescribed for the management of benign prostatic hyperplasia and are known to induce morphological and metabolic changes in prostatic tissue. This narrative review summarizes current evidence on the impact of 5-ARI therapy on multiparametric magnetic resonance imaging (mpMRI) findings and the potential clinical implications. While some studies report reduced discrimination on T2-weighted and apparent diffusion coefficient (ADC) metrics after long-term exposure, others suggest improved lesion visibility due to a more homogeneous benign background. Most studies found no significant difference in the Prostate Imaging Reporting and Data System (PI-RADS) lesion distribution between 5-ARI users and non-users. However, conflicting evidence exists regarding mpMRI sensitivity and specificity in 5-ARI-treated patients. Limited data is available on the effect of 5-ARIs on local staging accuracy. Overall, the effect of 5-ARIs on prostate mpMRI interpretation appears complex, highlighting the need for prospective studies and treatment-adjusted risk assessment tools to support clinical decision-making.