Indocyanine green fluorescence imaging system for sentinel lymph node biopsy in early breast cancer patients.

Abstract

649 Background: Sentinel lymph nodes (SLN) biopsy is a useful method to assess axillary lymph node status in early breast cancer. Indocyanine green (ICG) fluoresces by irradiating the excitation light when it unites with the serum protein. In the study, we present a novel method that allows the detection of SLN with high sensitivity using ICG fluorescence imaging. Methods: A 0.5% ICG solution combined with indigo carmine was intradermally injected for 0.3 mL in the areola closest to a tumor. Fluorescence imaging device (Photodynamic Eye: Hamamatsu Photonics Co.) was obtained using a charge coupled camera and light emitting diodes at 760 nm as the light source. Subcutaneous lymphatic channels draining from the areola to the axilla or other directions were visible by fluorescence imagings immediately. The SLN were then dissected by fluorescence navigation. Results: This study enrolled 175 patients with clinically node-negative breast cancer. Their average age was 52.8 years (ranged from 29 to 82 years). Sixty one patients were premenopausal, and 114 patients were postmenopausal. There were 112 cases with T1 lesions and 63 cases with T2 lesions. Subcutaneous lymphatic channels and SLN were successfully visualized in all patients. One lymphatic channel to the axilla was 55% (95/175), two channels were 29% (51/175), and three channels were 15% (27/175). The channels to other directions were not seen. The number of fluorescence SLN ranged from 1 to 6 (mean: 3.1), and blue dyed SLN ranged from 0 to 3 (mean: 1.2). In the latter, SLN were not identified in 64 patients (identification rate: 63.4%). Twenty three patients had lymph node metastases pathologically. All of them were recognized by fluorescence imagings, but, in 12 patients, lymph nodes with metastases were not identified by a vital dye. A significant correlation was seen between BMI and the time to arrival at the axilla. Conclusions: This ICG fluorescence imaging system presents a novel method for SLN mapping, which allows easy, highly sensitive and real-time imaging-guided SLN mapping in patients with early breast cancer. We hope that this method will provide with detection rate and negative predictive value in SLN navigation surgery. No significant financial relationships to disclose.