Ex vivo fluorescence confocal microscopy: the first application for real-time pathological examination of prostatic tissue

Objective: To report the first application of ex vivo fluorescence confocal microscopy (FCM) - a novel optical technology that is capable of providing fast microscopic imaging of unfixed tissue specimens- in the urological field assessing its diagnostic accuracy for non neoplastic and cancerous prostate tissue (prostatic adenocarcinoma) compared to the 'gold standard' histopathological diagnoses. Patients and methods: In all, 89 specimens from 13 patients with clinically localised prostate cancer were enrolled into the study. All patients underwent robot-assisted laparoscopic radical prostatectomy with fresh prostatic tissue biopsies taken at the end of each intervention using an 18-G biopsy punch. Specimens were randomly assigned to the three collaborating pathologists for evaluation. Intra- and inter-observer agreement was tested by the means of Cohen's κ. The diagnostic performance was evaluated on receiver operating characteristic curve analysis. Results: The overall diagnostic agreement between FCM and histopathological diagnoses was substantial with a 91% correct diagnosis (κ = 0.75) and an area under the curve of 0.884 (95% confidence interval 0.840–0.920), 83.33% sensitivity, and 93.53% specificity. Conclusion: FCM seems to be a promising tool for enhanced specimens' reporting performance, given its simple application and very rapid microscopic image generation (<5 min/specimen). This technique may potentially be used for intraoperative pathological specimens' analysis.