The problem of axillary staging in breast cancer after neoadjuvant chemotherapy. Role of targeted axillary dissection and types of lymph node markers.

Targeted axillary dissection (TAD) consists of a new axillary staging technique that combines sentinel lymph node biopsy (SLNB) and clipped lymph node biopsy (CLNB) in the same surgery, in order to re-stage patients with breast cancer and positive axillary lymph nodes undergoing neoadjuvant chemotherapy (NAQT). Prior to the NAQT, the affected lymph node is punctured and a solid marker is left inside echo-guided, in order to biopsy it in the subsequent surgery. There are numerous types of markers: metallic (steel, titanium or polyglycolic acid clips), radioiodine or ferromagnetic seeds, which differ in the method of location (wire, gamma-detection or magnetic probe). The aim of this study is to perform a systematic review about the current status of the TAD, as well as to explain the different techniques and types of axillary marking, based on the current available evidence.