Imagerie préopératoire de l’extension ganglionnaire initiale et locorégionale des cancers du sein

Abstract

Although its use is underestimated, the lymph node area should be thoroughly investigated prior to treatment so that the right course of therapy can be selected, especially axillary surgical procedures, which may occasionally be performed after neoadjuvant chemotherapy. Ultrasonography plays a pivotal role in this assessment, as the high resolution waves enable metastatic tumours larger than 3 mm to be investigated, while aspiration biopsy techniques can confirm this spread in nearly 80% to 90% of cases. Evidence of pre-operative spread to the lymph nodes means that the surgeon no longer needs to perform a sentinel lymph node biopsy, which requires expensive equipment and a specialist team. When spread to the lymph nodes is proven or highly suspected, layered imaging techniques (computerised axial tomography and/or magnetic resonance imaging) will enable this spread to be quantified so that the extent of surgery and the amount of radiotherapy can be determined. Positron emission tomography is being developed and may also help in lymph node staging. No technique has a sufficiently high detection failure rate, which means that surgical investigation will never be required; however, the sentinel lymph node biopsy should be carried out only for patients considered as not needing surgery or radiotherapy after an extensive ultrasound investigation. The expected benefits and current limitations of the imaging techniques are being developed.