Abstract
PURPOSE: Mitoxantrone hydrochloride injection for tracing (MHI) is a novel lymphatic tracer recommended for sentinel lymph node (SLN) biopsy (SLNB) in breast cancer. However, whether MHI can be detected under near-infrared fluorescence and the optimal MHI concentration and injection timing for SLNB remain unclear. This study characterized the fluorescent properties of MHI and explored its optimal application conditions for SLNB. METHODS: A total of 103 patients with clinically lymph node (LN)-negative breast cancer were enrolled who underwent mastectomy with SNLB followed by completion axillary lymph node dissection (ALND) were enrolled. Specifically, 32 patients (cohort I) were randomly allocated into four groups (undiluted, 1:2 dilution, 1:5 dilution, and 1:10 dilution) to determine the optimal concentration for fluorescence imaging, which was further confirmed in an additional 31 patients (cohort II). Subsequently, 40 patients (cohort III) were intraoperatively injected with either methylene blue (MB) or MHI/indocyanine green (ICG), and their lymphatic drainage imaging results were compared. RESULTS: Undiluted MHI was identified as the optimal concentration for both visible dye and near-infrared fluorescence imaging. In all 39 patients (eight patients from cohort I and all the patients in cohort II) injected with undiluted MHI, lymphatic vessels were visible on the body surface, along with an SLN detection rate of 94.9% and a false-negative rate (FNR) of 5.26%. A waiting time of 5 min was recommended as the optimal dyeing time before skin incision for SLNB. Furthermore, MHI demonstrated comparable SLN detection rate and lymphatic vessel imaging rate to those of MB and ICG with high specificity and operational convenience. CONCLUSION: MHI is a feasible fluorescence tracer for SLNB, with its dual advantages of visual clarity (like MB) and lymphatic specificity (like ICG). These combined advantages may enhance the accuracy and practicality of SLNB in breast cancer.