BACKGROUND: Near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) has been recently introduced for lymphatic mapping in several tumors. We aimed at investigating whether this technology may improve the intraoperative visualization of lymph nodes during robotic gastrectomy for gastric cancer.
METHODS: Between June 2014 and June 2018, a total of 94 patients underwent robotic gastrectomy with D2 lymph node dissection for gastric cancer. In 37 patients, ICG was injected endoscopically into the submucosal layer around the tumor the day before surgery. After propensity score matching, the results of these 37 patients were compared with the results of 37 control patients who had undergone robotic gastrectomy without ICG injection.
RESULTS: Among the 37 patients within the ICG group, no adverse events related to ICG injection or intraoperative NIR imaging occurred. After completion of D2 lymph node dissection, no residual fluorescent lymph nodes were left in the surgical field. A mean of 19.4 ± 14.7 fluorescent lymph nodes was identified per patient. The mean total number of harvested lymph nodes was significantly higher in the ICG group than in the control group (50.8 vs 40.1, P = 0.03). In the ICG group, 23 patients had metastatic lymph nodes. The accuracy, sensitivity, and specificity of ICG fluorescence for metastatic lymph nodes were 62.2%, 52.6%, and 63.0%, respectively.
CONCLUSION: Our study indicates that NIR imaging with ICG may provide additional node detection during robotic surgery for gastric cancer. Unfortunately, this technique failed to show good selectivity for metastatic lymph nodes.