Navigating technical variations and outcomes in indocyanine green-guided lymph node mapping for colorectal cancer

Indocyanine green is a fluorescent dye used in a wide range of specialties, including colorectal surgery. Although indocyanine green fluorescence imaging has been well established for assessing colorectal anastomotic perfusion, its role in lymph node mapping in colorectal cancer remains unclear. This narrative review aimed to provide an overview of the mechanism of action of indocyanine green-fluorescence imaging and its role in lymph node mapping in colorectal cancer.

PubMed/MEDLINE was searched through July 2026 for studies evaluating the use of indocyanine green-fluorescence imaging for lymphatic mapping and lymph node identification in colorectal cancer. Findings were narratively summarized.

Indocyanine green-fluorescence imaging may improve visualization of lymphatic drainage and support a more complete lymphadenectomy. Meta-analyses have reported pooled lymph node detection rates of 91% and 86.8%, with substantial variation by tumor location, disease stage, and mapping technique, with generally lower detection rates in rectal than in colon cancer. Pooled sensitivities of 63%, 64.3%, and 71% were reported, corresponding to false-negative rates of 37%, 35.7%, and 29%, respectively. Although indocyanine green-fluorescence imaging was associated with an increased lymph node harvest and occasionally modified resection strategy, data on long-term survival remain limited and inconsistent. Heterogeneity in indocyanine green dose and concentration, injection route and timing, imaging platforms, and outcome definitions limits comparison across studies.

Indocyanine green-fluorescence imaging might be a valuable tool for intraoperative lymphatic mapping and enhancing lymphadenectomy; however, substantial methodologic heterogeneity precludes definitive conclusions regarding its diagnostic accuracy for nodal metastatic status. Standardized protocols and high-quality prospective studies are needed to define its optimal role and long-term oncologic impact.