Fluorescence indocyanine green (ICG) for sentinel-lymph-node mapping in colorectal cancer: a systematic review

Modern surgical guidance in laparoscopic colon cancer procedures could be enhanced by visualizing lymphatic flow during surgery, already helping surgeons in determining the precise extent of digestive resection and could be useful in lymphadenectomy. Related to oncological procedure, lymphadenectomy is mandatory to assess the extension of the disease. To explore this approach, the objective of this review is to examine the use of indocyanine green fluorescence imaging for real-time in vivo identification of lymphatic flow and especially sentinel nodes in patients undergoing elective surgery for colorectal cancer.

A systematic review was conducted to identify relevant studies on sentinel node mapping using indocyanine green (ICG) in colorectal cancer surgery. A comprehensive search was performed in electronic databases including PubMed, Embase, and Cochrane Library from inception to December 2024. The search strategy incorporated relevant keywords and MeSH terms, combining variations of "colorectal neoplasms," "sentinel lymph node," "indocyanine green," and related terms. The search was limited to articles published in English language.

A total of 405 studies were identified across all databases. After screening, 45 full-text articles were assessed for eligibility, and 12 studies were ultimately included in the systematic review. ICG-FI has not yet demonstrated superiority over the standard blue dye technique. Moreover, a notable heterogeneity exists among the reported studies concerning ICG dosage, injection methods and the definition of positive LN status for sensitivity calculations, making direct comparisons challenging.

Despite the potential shown with other surgical oncological resections, ICG-FI requires further investigation and standardization in protocols and indications to fully harness its capabilities for SLN detection in CRC, especially metastatic nodes. Larger patient populations should be considered in future research to comprehensively assess its efficacy. This systematic review highlights the heterogeneity and limitations of current evidence regarding ICG-FI for SLN detection in colorectal cancer. While preliminary results are encouraging, further well-designed prospective trials are required before routine clinical implementation can be recommended.