Multiphoton microscopy for structure identification in human prostate and periprostatic tissue: implications in prostate cancer surgery

OBJECTIVE To test whether multiphoton microscopy (MPM) might allow identification of prostatic and periprostatic structures with magnification and resolution similar to gold standard histopathology. MATERIAL AND METHODS The present study included 95 robotic radical prostatectomy patients who consented to participate in an Institutional Review Board-approved study starting in 2007. The types of specimens used for imaging were excised surgical margins and biopsies, and sections obtained from the excised prostate. The specimens were imaged with a custom-built MPM system. All images were compared with haematoxylin/eosin histopathology of the same specimen. RESULTS MPM of freshly excised, unprocessed and unstained tissue can identify all relevant prostatic and periprostatic structures, such as nerves, blood vessels, capsule, underlying acini and also pathological changes, including prostate cancer. Histological confirmation and correlation of these structures and pathologies have validated the findings of MPM. CONCLUSIONS MPM shows great promise as a tool for real- time intra-surgical histopathology without needing excision or administration of contrast agents. The results will, however, need to be confirmed in true surgical settings using a miniaturized MPM microendoscope.