Objectives To determine the diagnostic performance of ex vivo fluorescence confocal microscopy (FCM) for prostate cancer detection in magnetic resonance imaging (MRI)‐targeted biopsy specimens using final histopathology as the reference standard, and to quantify workflow component times relevant to same‐day implementation. Patients and Methods In this single‐centre prospective observational study, men undergoing MRI‐targeted transperineal prostate biopsy were enrolled. Targeted biopsy cores were imaged ex vivo using a Histolog® FCM scanner (SamanTree Medical SA, Lausanne, Switzerland) after rapid acridine orange immersion and prior to routine histopathological processing. Two board‐certified genitourinary pathologists independently reviewed FCM images in a blinded fashion and classified each specimen as positive or negative for prostate cancer and clinically significant cancer (CSC), defined as International Society of Urological Pathology Grade Group (GG) ≥2. Diagnostic performance was calculated against final histopathology. Workflow feasibility was assessed by measuring specimen preparation, scanning, and interpretation times. Interobserver agreement and exploratory discordance analyses were performed. Results A total of 50 MRI‐targeted biopsy specimens from 44 patients were analysed, of which 33 (66%) contained prostate cancer and 17 (52%) met criteria for CSC. For cancer detection, Reader 1 achieved 87.9% sensitivity and 94.1% specificity, and Reader 2 achieved 97.0% sensitivity and 76.5% specificity, with overall accuracy of 90% for both readers. Interobserver agreement for cancer detection was 88% ( κ = 0.74), and for CSC was 86% ( κ = 0.61). Mean specimen preparation and interpretation times were ~2 min each, with standardised scanning time of 50 s, enabling complete FCM assessment in <5 min per target. Discordance was concentrated in GG 2 disease and Prostate Imaging‐Reporting and Data System (PI‐RADS) 3 targets, while higher‐grade cancers and PI‐RADS 5 lesions were uniformly concordant. Conclusion Ex vivo FCM provides rapid, accurate, and reproducible assessment of MRI‐targeted prostate biopsy specimens for cancer detection within clinically feasible timeframes. These findings support FCM as a same‐day diagnostic adjunct and justify prospective trials evaluating real‐time implementation during targeted biopsy.
Younis et al. (Sat,) studied this question.