The use of indocyanine green as the only tracer for the identification of the sentinel lymph node in breast cancer: safety and feasibility.

BACKGROUND

Sentinel lymph node biopsy (SLNB) is now considered the "gold standard" for axillary staging in the treatment of breast cancer. Most of the lymph node mapping experiences have been performed with a radioisotope (albumin-Tc99m) associated or not with the intraoperative injection of a dye, such as Patent-Blue V. Recent studies have shown how the use of indocyanine green (ICG; a drug used for diagnostic use for many years in other sectors) as a fluorescent tracer, allows to obtain alone detection rate of the sentinel lymph node similar or even better, without the risks related to radioactivity and with better use of resources.

METHODS

From March 2020 to February 2021, 184 patients with breast cancer cN0, candidate for SLNB were enrolled at the Complex Operative Unit (UOC) of Breast Surgery, Breast Unit of the Hospital of Verona. The ICG was injected into the periareolar site and was used the NOVADAQ SPY Elite system (Stryker) for transcutaneous intraoperative observation of fluorescence. The primary objective of the study is the evaluation of the feasibility of the technique and its sensitivity in the identification of sentinel lymph node; among the secondary endpoints the recognition of predictive factors on the identification (t1-t0) and extraction (t2-t1) times of the sentinel lymph node, and on the number of lymph node uptake pathways. Finally, was analyse the safety of the technique.

RESULTS

The sentinel lymph node was detected and removed in 98.3%. The average number of sentinel lymph nodes extracted is 1.527, while the average number of total lymph nodes (TLNs) extracted is 3.375. The sensitivity of the sentinel lymph node detection technique with ICG, turns out to be 100%. Finally, in the literature, lymphatic function decreases with increasing age, reducing the identification rate of the SLN; this is not confirmed in our study.

CONCLUSIONS

Our study confirms the use of the only ICG tracer for SLNB in cN0 breast cancer, demonstrating that it is a safe, effective and sensitive technique, which also allows to reduce costs, risks and organizational efforts.