European Association of Urology guidelines now recommend performing magnetic resonance imaging (MRI)-targeted with peri-lesional biopsies rather than traditional systematic biopsies. In patients with MRI-detected prostate cancer, the characteristics and therapeutic implications of concomitant MRI-undetected disease requiring systematic biopsy to identify are unclear. This was investigated through exploratory analyses of the PROMIS and PICTURE trials.
Patients with one or two suspicious quadrants on MRI, either ipsilateral or contralateral, and who underwent 5-mm transperineal template mapping biopsy were included. MRI-detected and -undetected lesions were compared and the impact of systematic biopsies on focal therapy planning was assessed. Cancer definitions used were Grade Group 2-5 and Grade Group 3-5.
Overall, 306 patients were included. A total of 240/306 (78%) had cancer diagnosed; 215/306 (70%) had MRI-detected cancer, with 44/306 (14%) having both MRI-detected cancer and additional MRI-undetected cancer. MRI-detected cancers had greater Grade Group and maximum cancer core length than MRI-undetected cancers (p < 0.001 for each). Of 127 patients eligible for focal therapy based on MRI-targeted biopsy alone, if whole gland biopsy were performed instead then 116/127 (91%) would not require a change to treatment template (p = 0.1). Adding contralateral hemigland biopsy to MRI-targeted biopsy identified all patients requiring a change to their treatment template. To ensure correct focal therapy planning for all, the number-needed-to-biopsy using additional contralateral hemigland biopsy instead of MRI-targeted biopsy alone was 12.
In this exploratory analysis, MRI-targeted biopsy alone was sufficient for detecting Grade Group 2-5 and Grade Group 3-5 cancer and was also sufficient for planning focal therapy, with the addition of contralateral systematic biopsies only altering focal therapy planning in 9%. Prospective validation of these findings, particularly regarding focal therapy planning, is needed.
European urology oncology. 2026 Jun 16 [Epub ahead of print]
Alexander Light, Max Peters, Archana Gopalakrishnan, Nikhil Mayor, Alex Freeman, Mark Emberton, Hashim U Ahmed, Taimur T Shah
Imperial Prostate, Department of Surgery and Cancer, Imperial College London, London, UK; Imperial Urology, Charing Cross Hospital, Imperial College Healthcare NHS Trust, London, UK. Electronic address: ., Radiotherapiegroep, Deventer, The Netherlands., Imperial Prostate, Department of Surgery and Cancer, Imperial College London, London, UK; Imperial Urology, Charing Cross Hospital, Imperial College Healthcare NHS Trust, London, UK., Department of Cellular Pathology, University College London Hospitals NHS Foundation Trust, London, UK., Division of Surgery and Interventional Science, University College London, London, UK; Department of Urology, University College Hospital, University College London Hospitals NHS Foundation Trust, London, UK.