Sentinel lymph node mapping of the stomach using fluorescent magnetic nanoparticles in rabbits

BACKGROUND/AIMS: Sentinel lymph node (SLN) mapping of the stomach cancer using available techniques is limited by unpredictable lymphatic drainage patterns and skip metastasis. The aim of this study was to test the feasibility of gastric SLN mapping using fluorescent magnetic nanoparticles (FMNP) of uniform nano-size. METHODS: Biocompatible silica-overcoated magnetic nanoparticles containing rhodamine B isothiocyanate (RITC) within a silica shell of controllable thickness with 60 nm thickness were used as model nanomaterials. Gastric lymphatic mapping was performed by injecting 100 microL of either FMNP or isosulafan blue subserosally. Gastric injections (n=7) were made into the body, approximately 5 cm from the lesser curvature of rabbits. Sentinel lymph nodes were visualized using fluorescent nanoparticle detection system. RESULTS: In 7 rabbits, it was demonstrated that FMNP quickly and accurately detected sentinel lymph nodes. Injection into the stomach resulted in identification of a retrogastric lymph node. Histological analysis in all cases confirmed the presence of nodal tissue. CONCLUSIONS: FMNP can be a potential alternative to existing tracers in the detection of SLN in this animal experiment.