Validation protocol of sentinel node biopsy for breast cancer using radioactive tracer at the Institute of Oncology Bucharest "Prof. Dr. Alexandru Trestioreanu"

The sentinel ganglion concept originates in the assumption according to which the primary tumor drains into a specific lymph node area and then runs through the lymphatic nodes in an orderly, sequential mode. When neoplastic dissemination along the lymphatic pathway occurs, there is an initial invasion of a specific lymph node (rarely more than one) located on the drainage route. That first lymph node has been identified as the sentinel node, which mirrors the regional lymph node status. In order to establish the indication for lymphadenectomy and avoid the situations in which such a surgical procedure would be of no use (N-), the only correct method consists in the identification and biopsy of the sentinel node which can be performed using vital staining (blue dye), radioactive tracers or both. The technique of sentinel lymph node identification and biopsy by means of radioactive tracing includes: -pre-surgical lymphoscintigraphy, -identification of the sentinel lymph node and its excisional biopsy, -intra-operative histopathological examination, paraffin embedded sections and immunohistochemical stains of the sentinel lymph node. The paper presents the refinement of the technique and the validation of the method for identification and biopsy of the sentinel lymph node in breast cancer with the intra-operative use of NEOPROBE 2000 gamma probe at the "Prof. Dr. Alexandru Trestioreanu" Oncological Institute in Bucharest. It is a prospective study which enrolled 93 patients with breast cancer between September 2003-December 2005, who underwent sentinel node biopsy. Complete axillary dissection (back-up lymphadenectomy) was performed in all cases. By comparing the pathological results of the frozen section of the sentinel node, with the paraffin embedded and immunohistochemical ones of the remaining axillary nodes, we present the following

Results: sensibility 97,15% (34/35), specificity 100% (93/93), positive predictive value 100% (34/34), negative predictive value 98,3% (58/59).