Indocyanine Green (ICG) fluorescence guided sentinel node biopsy for axillary nodal staging in breast cancer

Sentinel lymph node (SLN) biopsy is an accepted method for staging of axillary lymph nodes in patients with early breast cancer. Patients with negative SLN can be spared axillary lamph node dissection (ALND) with a significantly lower incidence of numbness, pain, impaired mobility and delay to return to work compared to ALND. SLN biopsy has been performed using different techniques, i.e. injection of blue dye, radioactive colloid or the combination of both. The average rate of SN identification using blue dye and radiocolloids is more than 95%, but results are ranging from 65% to 98%. However, there are concerns about sporadic limited availability and additional cost for radiocolloids that includes a lymphoscintigraphy for improved preoperative orientation for extra-axillary nodes and a handheld gamma probe. Furthermore, there are potential radiation hazards with the use of radiocolloids. There is recent evidence that Indocyanine green (ICG) could be a candidate for fluorescence guided SLN biopsy. ICG is a popular reagent that is clinically approved for the use of intravenous injection and has been applied in ocular arteriography and in the identification of gastric mucosal vessels. The reagent is a 776Da di-sulfonated molecule and shows a NIR fluorescence that has a moderate affinity binding site on human serum albumin. It rarely produces side effects and we observed no allergic reactions during the study. The advantages of both radiocolloid and blue dye could be combined using fluorescent dye for sentinel node detection, namely transcutaneous real-time lymphography, lymphatic and SLN staining and identification of lymphatic abnormalities. This study was performed to investigate the clinical approval of ICG fluorescence imaging for SLN detection. Peritumoreous injection of approximately 10mg ICG (2ml with regard to 5mg/ml) was performed intraoperatively 10 min before transcutaneous real-time lymphography with laser induced fluorescene by a camcorder. After transcutaneous identification of a potential Sentinel Lymph Node (SLN), dissection was proceeded lasting about 5-15min to identify and prepare the SLN. Fluorescence was checked after removal of SLN, SLN was sent to pathology and procedure lasted overal time of about 20-30 min. SLN was performed one time for each patient.