Despite the theoretical superiority of robotic technology, surgical outcomes following robotic surgery have shown little benefit over conventional laparoscopic surgery. At present, studies have evaluated the value of robotic technology in clinical practice, including EndoWrist®, TilePro®, Firefly®, and Single-Site®, and have demonstrated the possibility of added clinical value, specifically in regards to decreased postoperative pancreatic fistula, usefulness as a multi-display education system, visualization of lymphatic channels, and implementation of reduced-port robotic gastrectomy. However, these technologies have only been applied independently and not in a well-organized manner.

Maximizing radicality and safety while minimizing invasiveness are critical to bettering cancer surgery. We hypothesize that robot technology can affect these factors positively and that the use of appropriate parameters thereof could help shed more light on the benefits of a robotic system in gastric cancer surgery.

1. Radicality: added benefit of Firefly® for lymph node visualization Number of retrieved lymph nodes can be considered a surrogate marker of long-term survival. In our proposed study, we will focus on the number of retrieved (lymph nodes as the primary outcome. Additionally, bleeding, which is known to be associated with poor overall survival, will be measured as a secondary outcome. Three-year recurrence free survival and 5-year overall survival will be followed up.
2. Safety: benefit of Firefly® in differentiating lymph nodes from other organs and benefit of a magnified view and EndoWrist® Although robotic surgery reportedly shows less in-hospital and outpatient complication rates, a higher number of enrolled patients is needed to statistically validate these results. In the currently proposed study, these would be secondary outcomes. We have experienced the benefit of using fluorescence imaging to differentiate lymph node from biliary trees and pancreas parenchyma. As a reflection thereof, bleeding would be measured as parameter of unintended injury to a normal organ. To evaluate injury to pancreas parenchyma and postoperative pancreatic fistula, amylase/lipase levels in serum and drainage fluid will be measured.
3. Invasiveness: value of Single-Site® Serum CRP (C reactive protein) levels (day 0, day 3, day 5, and 4 weeks after surgery) and pain scores (at 6 hr, 12 hr, 24 hr, 48 hr, and 72 hr after surgery) will be measured to evaluate surgical trauma to the patients. Satisfaction on the wound will be evaluated using Korean version of the body image scale at one month after surgery.

Inclusion Criteria:

• Documented diagnosis of gastric adenocarcinoma and scheduled to undergo minimally invasive gastrectomy
• Age > 20 years
• A patient who signed the informed consent

Exclusion Criteria:

• Mentally incompetent, illiterate, or pregnant patients
• Requiring major combined resection (colon, pancreas, etc., except the gall bladder)
• Having metastatic or non-resectable lesion.
• Active other cancer history