Colonic and gastric cancer metastatic lymph nodes: applications of autofluorescence-based techniques

Lymphadenectomy and extended lymphadenectomy are still controversial issues in surgical oncology.The detection methods for metastatic lymph nodes include lymphoscintigraphy and radiolabelled antibody, but immunohistochemical sentinel lymph node (SLN) identification is commonly used. The potential diagnostic use of cell and tissue autofluorescence (AF) is well known. Here we review our studies on the application of AF-based techniques for diagnosiing metastatic lympg nodes. We had previously demonstrated that AF imaging allows discrimination between hyperplastic and primary neoplastic lymph nodes. Our more recent studies show that the combination of autofluorescence micrscopy can be applied to the diagnosis of secondary neoplastic lymph nodes in gastric and colorectal cancer. These techniques have been validated by histochemical and immunohistochemical methods. Studies are in progress to select the best due tracer for SLN identification, to improve image quality and to develop a software for automatic analysis of tissue AF to help the decision-making process during surgery