Indocyanine Green Fluorescence Imaging System As an Alternative to the Conventional Sentinel Lymph Node Mapping Using A Radiotracer in Breast Cancer.

1091 Background: Near-infrared fluorescence signal of indocyanien green (ICG) can visualize subcutaneous lymphatic flows and draining (sentinel) lymph nodes (SLNs). In fluorescence ICG Breast Study Group 01 study (fICG BR01), this ICG fluorescence mapping was superior to the dye method in early stage breast cancer (Sugie T, et al. Ann Surg Oncol 2013). The following fICG BR02 study evaluates clinical usefulness of this ICG fluorescence method in comparison to the conventional radioisotope (RI) method. Methods: On the day before or on the day of SLN biopsy, 99mTc-labelled colloid was injected into the subareolar region of each patient. Before the start of operation, ICG was injected into the subareolar region and lymphatic flows bound for the axilla were traced with PDE camera (Hamamatsu Photonics Co, Japan). A real-time navigation surgery by ICG florescence imaging enabled to identify SLNs to be excised. A gamma probe was used to verify no residual radioactivity in the axilla after SLN removal. Results: A total of 847 women with T1-2 breast cancer were enrolled and 821 pts. were included in the per-protocol final analysis. The median pts. age was 55 (range, 22-80) years and the median BMI was 22.1 (range, 14.9-38.8) kg/m2. There was no significant difference in the detection rate between the ICG and RI method (97.2% vs 97.0%). However, a combination of ICG and RI achieved a significant higher detection rate than RI alone (99.8% vs 97%, p<0.001). The involvement of SLNs was found in 180 pts. and a detection rate of positive SLN using ICG fluorescence and RI was 93.3% and 90%, respectively. The detection rate of SLNs with a combination of ICG and RI was improved significantly compared with RI alone (97% vs 90%, p<0.001). There is no serious adverse event due to hypersensitivity to ICG. Conclusions: The ICG fluorescence method has a high detection rate of SLN comparable with that of the RI method. A combination of these two methods yield a significant improvement of SLN detection compared with RI alone. The results of this study confirm that ICG fluorescence imaging system is an alternative and/or additive to the conventional SLN mapping using a radioactive tracer in breast cancer. Clinical trial information: UMIN000005167.