Indocyanine green fluorescence imaging for sentinel lymph node detection in colorectal cancer: A systematic review

Indocyanine green fluorescence-imaging (ICG-FI) has emerged as a potential tool for increasing the accuracy of staging of patients with primary colorectal cancer (CRC) through the detection of sentinel lymph nodes (SLNs). Here, we report the results of a systematic review of the available literature in the clinical setting of ex vivo and in vivo ICG-FI for the detection of SLNs in primary colorectal cancer. PubMed, Scopus, and Cochrane literature databases were searched for original articles on the use of ICG in the setting of clinical studies of CRC. Eighty studies were identified and screened, 23 were assessed for eligibility and 10 were included for review. Both ex vivo and in vivo ICG-FI are reported to be feasible for the detection of SLNs in CRC. The reported sensitivity of both techniques remains low, varying from 0% to 100% for the in vivo technique and 57% for the ex vivo technique. ICG-FI has not yet been shown to perform better than the standard blue dye technique. In addition, large variability among reported studies in terms of techniques used (ICG dose, type of injection), type of pathologic analyses performed (HE, IHC, serial section), and definition of positive LN status for sensitivity calculations made them difficult to compare directly. ICG-FI is a promising technique for the detection of SLNs in the setting of CRC but more work needs to be done to clearly define protocols and indications for its use and to test its efficacy in larger patient populations.