Sentinel Lymph Nodes Detection in Early-Stage Breast Cancer: ICG-Enhanced Fluorescence and Radioactivity Detection Methods Comparison

Abstract

Introduction: A sentinel lymph node biopsy (SLNB) is a standard procedure for surgical staging in the early stage of breast cancer, avoiding excess lymphadenectomy in most patients. Among the new methods of SLNB, there is a prospective method based on the use of indocyanine green (ICG) as a contrast medium. Numerous studies to assess the possibility of the routine use of ICG fluorescence method generally favored the use of ICG. The main issue discussed is whether it can be used alone or in combination with the RI method. In this work, using the specified device, we conducted a study aimed at intercomparing of ICG fluorescence imaging and the radioactivity detection methods in order to assess prospects for the use of the ICG method of imaging for SLN detection in early-stage breast cancer. Material and Methods: A prospective, non-randomized single-center study was conducted at the oncological breast unit Pavlov State Medical University, Russia. The study included 32 patients aged from 34 to 78 (median-55.2 years) with breast cancer (cTis-3, N0-2). 4 patients underwent surgery after neoadjuvant systemic treatment. 30-45 minutes before the surgery, additionally, 2 ml of the ICG solution was administered near the tumor margin via single skin puncture. The solution was prepared by dissolving 25 mg ICG in 20% of human albumin. Then the place of injection was massaged for at least 5 minutes. SLN biopsy was performed by two criteria by the presence of radioactivity in the axillary region, which was monitored using a handheld gamma-detector or by the ICG fluorescence, location of which was visualized using the ICG-Scope system. The lymph node was recognized as a sentinel if its intensity exceeded the background radioactivity level of 99mTc or exceeded the threshold value upon the ICG fluorescence, which was 1% of the standard sample intensity.