Indocyanine green fluorescence imaging in gastric cancer: Clinical efficacy, technical innovations, and future perspectives

Table 1 Indocyanine green injection methods comparison in gastric cancer surgery

Feature	Submucosal injection	Sub-serosal injection
Injection method	Under the guidance of preoperative endoscopy	Intraoperative direct injection
Ease of use	Performed by endoscopist	Performed by surgeon during surgery
	Not occupy surgical time	May be limited by visual field and operational space
Imaging clarity	Fluorescence is concentrated with clear boundaries; beneficial for precise tumor and lymph node localization	Prone to ICG leakage and diffusion; lead to dispersed fluorescence, contaminated surgical field, and significant background interference
Risk of leakage	Low; unlikely to contaminate the abdominal cavity and surgical field	High; prone to leakage into the abdominal cavity, widely contaminating adipose tissue, intestines, and other tissues, severely affecting observation
Impact on surgery	Minimal impact; surgery can proceed as planned even if injection fails or fluorescence is poor	Potential impact; leaked ICG may contaminate the surgical field and interfere with subsequent non-fluorescence guided procedures
Applicability and recommendation	Preferred method; especially suitable for tumor localization and lymph node tracing in early gastric cancer	Applicable when preoperative endoscopy is not feasible
Key advantage	Clean surgical field, high-quality imaging, does not interfere with surgery	No additional preoperative endoscopic procedure required

ICG: Indocyanine green.