New techniques for sentinel node biopsy in breast cancer

Abstract

Sentinel lymph node biopsy (SLNB) is still the standard of care for axillary nodal staging in patients with invasive breast cancer (BC) and clinically negative lymph nodes (LNs). It successfully replaced the more invasive and morbid axillary lymph node dissection (ALND). The actual standard for SLNB is the radioisotope (RI) with or without blue dye (BD) technique. Because of several drawbacks reported in worldwide experiences, new techniques have been developed in the last years: indocyanine green (ICG) fluorescence, superparamagnetic iron oxide (SPIO) nanoparticles and contrast-enhanced ultrasound (CEUS) using microbubbles. Whilst each technique has its own advantages/disadvantages they are increasing their efficacy and are candidate to represent a new standard for SLNB in next future. This is a comprehensive review of current limitations of conventional techniques besides the improvements and innovations of new methods which, anyway, need future randomized controlled trials to be fully validated.

Meta-analysis Comparing Fluorescence Imaging with Radioisotope and Blue Dye-Guided Sentinel Node Identification for Breast Cancer Surgery

“…[2][3][4] Gold standard lymphatic mapping uses a combination of blue dye (BD; patent blue, methylene blue, or isosulphan blue) and radioactive colloid. [8][9][10][11] This dual tracer approach facilitates high sensitivity and low false negative rates. 9 However, BD can cause allergic reactions in 1.8% of patients, of which approximately 23% are type I hypersensitivity and 69% are type IV skin reactions.…”

“…[8][9][10][11] This dual tracer approach facilitates high sensitivity and low false negative rates. 9 However, BD can cause allergic reactions in 1.8% of patients, of which approximately 23% are type I hypersensitivity and 69% are type IV skin reactions. 12 Additionally, BD can cause semi-permanent skin staining/tattooing, which may or may not fade after several months, 13 and the technique may fail to accurately identify all sentinel nodes when used in isolation.…”

Sentinel Node Biopsy after Neoadjuvant Chemotherapy for Breast Cancer: Preliminary Experience with Clinically Node Negative Patients after Systemic Treatment

“…Since many studies have shown a great variation in identification (IR) and false negative rates (FNR), the reliability of SLNB after neoadjuvant chemotherapy (NACT) remains questionable [ 5 , 6 , 7 , 8 , 9 , 10 ].…”

Preoperative localization of sentinel lymph node in breast cancer patients by silver wire insertion or liquid charcoal injection guided by CT lymphography

“…Performing axillary lymph node dissection as a substitute for sentinel lymph node biopsy even in the absence of radioisotope is no longer accepted. This explains the need for providing other effective alternatives for SLN detection in areas lacking availability of radioisotopes …”

“…On the other hand, depending on blue dye alone has some disadvantages such as the relatively lower identification rate, the need for cumulative surgeon experience, and the lack of possibility to locate the LN site before skin incision. This led to thinking about the need for developing other alternatives for SLN detection which can offer the same detection & accuracy rates and avoid the drawbacks of the already available methods …”