IMPORTANCE Fluorescent imaging with indocyanine green can be used to visualize lymphatics. Peritumoral injection of indocyanine green may allow for visualization of every draining lymph node from a primary lesion on near-infrared imaging. OBJECTIVES To evaluate the role of fluorescent lymphography using near-infrared imaging as an intraoperative tool for achieving complete lymph node dissection and compare the number of lymph nodes retrieved with the use of near-infrared imaging and the number of lymph nodes retrieved without the use of near-infrared imaging. DESIGN, SETTING, AND PARTICIPANTS This prospective single-arm study was conducted among 40 patients who underwent robotic gastrectomy between August 30, 2013, and July 21, 2014, at a single-center, tertiary referral teaching hospital. After propensity score matching, the results of these 40 patients were compared with the results of 40 historical control patients who underwent robotic gastrectomy without indocyanine green injection

In early gastric cancer (EGC), tumor invasion depth is an important factor for determining the treatment method. However, as endoscopic ultrasonography has limitations when measuring the exact depth in a clinical setting as endoscopists often depend on gross findings and personal experience. The present study aimed to develop a model optimized for EGC detection and depth prediction, and we investigated factors affecting artificial intelligence (AI) diagnosis. We employed a visual geometry group(VGG)-16 model for the classification of endoscopic images as EGC (T1a or T1b) or non-EGC. To induce the model to activate EGC regions during training, we proposed a novel loss function that simultaneously measured classification and localization errors. We experimented with 11,539 endoscopic images (896 T1a-EGC, 809 T1b-EGC, and 9834 non-EGC). The areas under the curves of receiver operating characteristic curves for EGC detection and depth prediction were 0.981 and 0.851, respectively. Among the factors affecting AI prediction of tumor depth, only histologic differentiation was significantly associated, where undifferentiated-type histology exhibited a lower AI accuracy. Thus, the lesion-based model is an appropriate training method for AI in EGC. However, further improvements and validation are required, especially for undifferentiated-type histology.

MSI gastric cancer was associated with good prognosis but there was heterogeneity in the recent studies. Changed epidemiology and effects of chemotherapy are potential causes of heterogeneity. Establishing a consensus for defining MSI in gastric cancer should be preferred for future studies.

Background Although various liver-directed treatment modalities, such as liver resection and radiofrequency ablation (RFA), have been applied to treat liver metastases from gastric cancer, optimal management of them remains controversial. In patients with liver metastasis from gastric cancer, we investigated the short-and long-term outcomes of liver resection and RFA and analyzed factors influencing survival. Methods A total of 98 gastric cancer patients with liver metastasis and no extrahepatic disease were treated by liver resection (n = 68) or RFA (n = 30). Short-and long-term outcomes were evaluated retrospectively for each of the liver-directed treatments. Results Severe complication rates did not differ between liver resection (18 %) and RFA (10 %) (p = 0.333). Only one treatment-related mortality occurred in the liver resection group. No statistically significant difference in survival was noted between the treatment groups. Median overall survival after liver resection was 24 months, with 3-year overall and progression-free survival rates of 40.6 % and 30.4 %, respectively. Median overall survival after RFA was 23 months, with 3-year overall and progression-free survival rates of 43.0 % and 37.4 %, respectively. Only the size of the metastases was shown to be an independent prognostic factor for gastric cancer patients with liver metastasis. Conclusions In select patients with liver metastasis from gastric cancer, liver resection and RFA showed satisfactory and comparable short-and long-term results. Thus, systemic chemotherapy may not be the only therapeutic option for patients with liver metastasis, and possible liver-directed treatment options for such patients should be considered on an individual basis.