Early-stage lesions are difficult to identify intraoperatively during colorectal cancer surgery. Therefore, preoperative lesion marking using a colonoscopic approach is crucial to confirm the location and extent of resection during surgery. Preoperative lesion location can help determine the optimal extent of resection, thereby increasing the accuracy of colorectal surgery. This is particularly true for cases requiring surgery after early-stage colorectal cancer or endoscopic tumor resection. Therefore, preoperative marking with indocyanine green (IDG) allows for laparoscopic identification of the lesion. This is crucial because it allows for precise lesion location, thereby enhancing surgical accuracy and preventing the need for unnecessary additional resections.

The recently developed indocyanine green (ICG)-hyaluronic acid mixture (LuminoMark™, Hanlim Pharm Co., Seoul, Republic of Korea) is a surgical marker combining indocyanine green with macroaggregated albumin (MAA). Its non-diffusing properties allow for precise lesion targeting. It addresses unmet needs of existing surgical markers, such as skin pigmentation and surgical site contamination. It effectively adsorbs onto cancerous lesions, enabling precise lesion location. Real-time tracking of the pigment allows for clear identification of the lesion's extent of removal, enhancing convenience and usability during surgery. It has already demonstrated superiority over existing labeling methods in a phase 3 clinical trial for breast lesions, receiving approval from the Ministry of Food and Drug Safety. Clinical trials are underway for various cancer types, including gastric and colon cancer, but it remains an over-approved drug.

Therefore, this study aimed to determine the accuracy of endoscopic labeling using a novel luminomarker for preoperative colon cancer lesion marking.

Inclusion Criteria:

• Adult patients aged 19-80 years
• Clinical T1-2, N0, without distant metastasis on imaging
• If surgical treatment is required after ESD (endoscopic mucosal resection)*
• If endoscopic lesion marking is required as determined by the attending physician

Exclusion Criteria:

• Patients diagnosed with distant metastases (M1)
• Severe hepatic or renal dysfunction (Child-Pugh Class C, eGFR <39 mL/min/1.73 m2)
• Pregnant or lactating women
• High risk of intestinal obstruction or perforation
• Patients deemed inappropriate by the investigator (high-risk patients, such as patients with lung or heart disease, risk factors for bleeding, hepatitis virus infection, or other cancers)
• Patients with a history of hypersensitivity to the luminomarker drug or its components
• Patients who have experienced skin hypersensitivity to the dye
• Patients who do not wish to participate in the study