Low‐cost Fluorescein as an Alternative to Radio‐colloid for Sentinel Lymph Node Biopsy—a Prospective Validation Study in Early Breast Cancer

Background Sentinel lymph node biopsy (SLNB) using radio‐pharmaceutical (RP) and a blue dye is gold standard for axillary staging in clinically node‐negative early breast cancer. High costs and limited availability of RP and/or gamma probe are major deterrents in performing SLNB in developing countries. Fluorescence‐guided SLNB can obviate the need for RP and gamma probe. Fluorescein is an inexpensive fluorescent lymphatic tracer. In this study, we compared SLN identification rate (SLN‐IR) and false negative rates (FNR) of fluorescein‐guided SLNB and radio‐guided SLNB using 99mTc‐Sulfur‐colloid, in isolation, or in combination with methylene blue dye (MBD). Methods Sixty‐five cN0 early and large operable breast cancer patients underwent validation SLNB using fluorescein (and blue LED light), 99mTc‐Sulfur‐colloid (and gamma probe) and MBD. Inj Fluorescein 4% was injected, 1 ml each peri‐tumoral and sub‐areolar five minutes before axillary incision. Axillary dissection was performed irrespective of SLNB histology. The SLN‐IR and FNR with various tracers and their combinations were compared. Results The mean number of SLNs identified was 3.5 ± 1.8 (range 1–6). The SLN‐IR using RP alone was 94%, fluorescein alone was 92%, and MBD alone was 82%. The SLN‐IR using fluorescein plus MBD combination was 95.4%, compared to 97% using MBD plus RP combination. FNR was 6.3% using fluorescein plus MBD, as well as RP plus MBD combinations. Conclusions SLN‐IR of > 90% and SLN‐FNR of < 10% using fluorescein plus MBD combination are in acceptable range, and are comparable to that of RP plus MBD combination. Fluorescein can replace RP for performing SLNB, in combination with MBD.