By uploading pre-operative patient information and patient CT data to RUS™, a virtual surgical environment with patient-specific relief prediction models can be provided. First, after uploading the CT and clinical information of a gastric cancer patient diagnosed with gastric cancer through an actual endoscopic biopsy and scheduled for robotic total gastrectomy, RUS™ will operate normally to check whether patient-specific surgical navigation is available before or during surgery. In particular, when using the patient-specific surgery simulation system provided by RUS™, the CT information provides a patient-specific 3D environment well, so it will be checked regarding whether the surgeon can use it before or during surgery without any particular problems. Using RUS™ software, navigation information is used before or during surgery, and among these, parts that can be quantitatively compared with actual measurements will be evaluated as a secondary research goal. After the surgery, the investigators plan to check the amount of bleeding, duration of hospitalization, and the rate of complications by performing robot gastrointestinal resection using the navigation system to ensure that there are no problems with patient safety.

• Obtain consent from a patient who is diagnosed with gastric cancer and is scheduled for robotic surgery.

  • Take an abdominal CT before gastric cancer surgery according to the prescribed protocol.

    • Upload patient information and CT information before surgery to RUS™, an endoscopic treatment image planning software, to build a 3D modeling navigation system for a patient-customized surgical environment. (Measure the time (in days) from the time the CT is uploaded to the time when the RUS™ software can be operated.)

      • Before surgery, use the RUS™ navigation system to check the patient's relief and anatomical structure, mark the planned trocar insertion site, and obtain distance information from the umbilical trocar.

        ⑤ After general anesthesia on the day of surgery, mark the Landmark 25 area on the abdominal wall using a surgical marking pen. In addition, the abdominal wall surface scan is performed using a laser 3D scanner.

        ⑥ After the undulations are formed, the deformed abdominal wall surface is scanned with a laser 3D scanner.

        ⑦ Evaluate the degree of agreement between the patient's actual relief state measured in steps ⑤ and ⑥ and the patient's relief model predicted through the relief prediction model in RUS™.

        ⑧ When the trocar is inserted through an anatomical landmark after the actual patient's relief, compare the position information of the trocar with the trocar position information of the RUS™ measured in advance in step ④ to check its accuracy.

        ⑨ Check whether the blood vessels that must be checked during the total gastrectomy procedure (left omentary artery, left umbilical vein, superior omentum, superior vena cava, left gastric artery, superior artery, and left hepatic branching left hepatic artery) are presented in the RUS™ blood vessel segmentation model.

        ⑩ Among the vessels mentioned in step ⑨, for the vessels suggested by RUS™ for vessels (left gastric artery, superior artery, left gastric vein, and gastric colonic vein), check the anatomical positional relationship and measure branch points during actual surgery. Check the accuracy of matching with the anatomical location information and branching distance of the segmentation model.

Inclusion Criteria:

• Among the subjects, the subjects are selected according to the following criteria:

  1. Those who have been diagnosed with gastric cancer and are scheduled for robotic total gastrectomy;

  2. A person who is 18 years of age or older and able to make independent judgment on their own;

  3. A person who can have a CT scan according to the established protocol;

  4. Before participating in the clinical trial, an interview was conducted in an independent space, the purpose and contents of the clinical trial were fully explained, and the consent to participate in this study was voluntarily given (approved by the institutional research ethics review committee) and those who signed.

     For reference, internal employees and immediate family members can also participate in this study unless there is a special reason for exclusion.

     Exclusion Criteria:

• If any of the following exclusion criteria are met among the subjects, participants will be excluded from this clinical trial:

  1. Vulnerable subjects (those who lack medical ability, or are illiterate, pregnant, newborns, minors (under 18), etc.);
  2. Persons who cannot have a CT scan according to the prescribed protocol prior to gastric cancer surgery (contrast agent allergy, creatinine 1.5 times the normal maximum, claustrophobia, etc.);
  3. Persons whose major artery/venous structure in the stomach or abdominal cavity has been altered due to previous surgery (due to gastric cancer or other abdominal surgery);
  4. Persons with residual gastric cancer with a history of gastric surgery;
  5. Persons who did not consent to this study or who withdrew consent.

Diagnosed as gastric cancer Patients who will be carried out Robotic Gastrectomy in Yonsei University Health System, Severance Hospital