Sentinel lymph node biopsy in N+ breast cancer with conversion into N0 after neoadjuvant chemotherapy.

Objective: Sentinel lymph node biopsy (SLNB) usefulness in breast carcinoma N+ converted to N0 after neoadjuvant chemotherapy (NC).
Material and Methods: Descriptive study including 16 females with infiltrating carcinoma with lymphatic metastasis confirmed by biopsy, leaving a metallic marker (MM) in pathological lymph nodes (LN). All patients underwent NC reaching a complete radiological response in LN. Lymphoscintigraphy was performed after ^99m Tc nanocoloid injection, obtaining planar images and SPECT/CT. Lymphatic drainage and concordance of sentinel node (SN) with MM was analyzed.
Results: SN was visualized in lymphoscintigraphy in 93.7% of cases. The SN coincided with the MM in 12/15 cases on SPECT/CT. The SLNB technique was completed on 14/16 patients, intraoperatively locating the GC in all of them. The SN was negative in 10 cases, 3 cases presented macrometastases and 1 micrometastases. Axillary lymphadenectomy (AL) was performed in a case of macrometastasis with>15,000cp/μARNm CK-19, absence of drainage and in one case that showed no coincidence with the MM due different Berg's level location. These last two cases presented lymph node metastasis. In the other two cases with not coincidence between the SN and the MM, a total of 4 lymph nodes were removed, showing no evidence of metastasis. Patients without AL were followed up for an average of 10 months (range 6-17), with no evidence of lymph node involvement.
Conclusion: SLNB in breast cancer with conversion into N0 after neoadjuvant treatment is a technique with good results and a low false negative rate.
(Copyright © 2018 Sociedad Española de Medicina Nuclear e Imagen Molecular. Publicado por Elsevier España, S.L.U. All rights reserved.)