Current and future perspectives of digital microscopy with fluorescence confocal microscope for prostate tissue interpretation: a narrative review

Fluorescence confocal microscopy (FCM) is an optical imaging technique providing digital microscopical images of fresh tissue in a real time fashion, without conventional processing. FCM has been widely applied in several fields of dermatology, including the detection of basal cell carcinoma and of cutaneous inflammatory diseases. The aim of the paper is to provide an overview of FCM applications in the field of prostate tissue interpretation and prostate cancer (PCa) detection. A Literature search (PubMed & Web of Science) was performed to identify articles concerned with the clinical and surgical applications of FCM in prostatic and periprostatic tissues interpretation. Overall, six articles were identified. All articles investigated the level of agreement between FCM and conventional histopathological analysis (hematoxylin-eosin, HE) for the discrimination between normal and PCa tissues. An investigative article on prostate samples retrieved from radical prostatectomy (RP) specimens and an atlas of FCM digital images from the same series were found. Two prospective clinical trials, comparing FCM and HE, pointed out a “substantial” to “almost perfect” discriminative performance of FCM for the diagnosis of PCa on prostate biopsy core. Finally, two studies investigated the intra-operative role of FCM during RP for the control of surgical dissection. In this setting, FCM could be used to analyse samples retrieved from suspicious peri-prostatic areas; FCM has also been tested for an en-face evaluation of flat slices obtained from the systematic sampling of the posterolateral aspects of the prostate, in a NeuroSAFE-like approach. Generally, FCM provides digital microscopical images of fresh tissue in a real time fashion, without requiring conventional processing. Currently, available studies confirmed a high concordance with conventional pathology for the detection of PCa. Further studies are required to validate the technology, to evaluate ISUP score attribution and to implement the fields of application of FCM for the treatment of prostate diseases.