BACKGROUND: 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 microliter 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.
Animals ; Coloring Agents/diagnostic use ; Female ; Fluorescent Dyes/*diagnostic use ; Lymph Nodes/pathology ; Male ; Models, Animal ; Nanoparticles/*diagnostic use ; Rabbits ; Rhodamines/diagnostic use ; Rosaniline Dyes/diagnostic use ; Sentinel Lymph Node Biopsy/*methods ; Stomach/*pathology ; Time Factors

The purpose of this study was to investigate the feasibility of sentinel node frozen biopsy to minimize the extensive pelvic lymph nodes dissection in early stage cervical cancer patients on the basis that the risk of skip metastasis to the paraaortic area is negligible. Twenty-six patients with early stage cervical cancer were enrolled in this study. Technetium-99m colloid albumin (Tc(99m)) was injected intradermally around the tumor for allowing preoperative lymphoscintigraphy and intraoperative hand-held gama probe detection of seninel nodes. For visual detection, isosulfan blue dye was injected into the peritumoral sites before peritoneal opening. Postoperative morbidity and negative predictive value were the endpoints of this study. The 26 patients, ranging in age from 32 to 71 yr, underwent intraoperative sentinel nodes mapping. All the patients underwent complete pelvic lymph nodes dissection including para-aortic nodes. There was one case with positive non-sentinel nodes despite the negative sentinel node by frozen biopsy (negative predictive value, 95.2%). This new technique of sentinel node mapping is safe and simple to perform. Further clinical trials using the combination of Tc(99m) and isosulfan blue dye are warranted and this technique will make a true advance for less aggressive management of patients with early stage cervical cancer.
Adult ; Aged ; Female ; Humans ; *Lymph Node Excision ; Lymph Nodes/pathology/radionuclide imaging/*surgery ; Middle Aged ; Pelvic Neoplasms/*pathology/radionuclide imaging/surgery ; Pelvis ; Predictive Value of Tests ; Rosaniline Dyes/metabolism ; Sensitivity and Specificity ; *Sentinel Lymph Node Biopsy ; Technetium Tc 99m Aggregated Albumin/diagnostic use ; Uterine Cervical Neoplasms/*pathology/radionuclide imaging/surgery