New fluorescence imaging method for sentinel lymph node biopsy in patients with early breast cancer.

Abstract

e11578 Background: Indocyanine green (ICG) is a popular diagnostic reagent for the examination of hepatic function and cardiac output. In this study, based on the fluorescence characteristics of ICG, we present a new method that enables the detection of sentinel lymph nodes (SLN) with high sensitivity using ICG fluorescence imaging. Methods: Fluorescence images were obtained using the fluorescence imaging system, the Photodynamic Eye (Hamamatsu Photonics Co., Japan). A 0.5% ICG solution combined with Indigocarmine was intradermally injected for 0.3 ml in the areola closest to a tumor. Subcutaneous lymphatic channels draining from the areola to the axilla or other directions were visible by fluorescence imagings immediately. The point where the fluorescence disappeared was identified on the skin, and the skin has been pressed with the capsule. The point of fluorescence seemed was then incised, and the SLN were then dissected by fluorescence navigation. Results: This study enrolled 202 patients with clinically node-negative breast cancer. Their average age was 53.9 years (ranged from 29 to 82 years). Sixty five patients were premenopausal, and 137 patients were postmenopausal. There were five cases of Tis lesions and 117 cases with T1 lesions and 80 cases with T2 lesions. Subcutaneous lymphatic channels and SLN were successfully visualized in all patients. One lymphatic channel to the axilla was 53%, two channels were 32%, and three channels were 16%. The channels to other directions were not seen. The number of fluorescent 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 76 patients (identification rate: 62.4%). Twenty three patients had lymph node metastases pathologically. All of them were recognized by fluorescence imagings, but, in 10 patients, lymph nodes with metastases were not identified by a blue dye. Conclusions: The fluorescence imaging method is therefore considered to be a new and effective method for SLN mapping, which allows easy, highly sensitive and real-time imaging-guided SLN mapping in patients with early breast cancer. The current results show that SLN mapping guided by ICG fluorescence imaging could therefore be a promising tool.