The purpose of this study is to assess the feasibility of image-guided surgery in patients with early stage gastric cancer using Robotic Surgery with Tile-pro program. For the assessment of the feasibility, conversion to open or laparoscopic surgery due to disturbance of will indicate the failure.

To assess the feasibility of image-guided surgery in patients with early stage gastric cancer using Robotic Surgery with Tile-pro program. For the assessment of the feasibility, conversion to open or laparoscopic surgery due to disturbance of will indicate the failure.

Diagnosis of early stage gastric cancer -> CT scanning & EUS for staging -> (Registration) -> Robotic surgery with image reconstruction -> Conversion rate, Tumor location & vascular anatomy correlation.

Inclusion Criteria:

• Patients who are older than 20 years
• Histologically confirmed gastric adenocarcinoma
• Patients who want robotic gastric cancer surgery
• Preoperative clinical stage Stage I (T1N0, T1N1, T2N0) diagnosed with EGD, EUS & CT scan
• No history of drug allergy
• creatinine < 1.5 X upper normal limit
• Informed consent

Exclusion Criteria:

• Previous history of upper abdominal surgery
• Patient refused the study