title: [Utility and advantages of single tracer subareolar injection in sentinel lymph node biopsy in breast cancer].
abstract: BACKGROUND
  Sentinel lymph node (SLN) biopsy is a reliable technique for determining axillary status in patients with early breast cancer. This technique is a minimally invasive procedure that can avoid the use of lymphadenectomy in patients without axillary involvement. We present a validation study of SLN biopsy with subareolar injection of 99mTc-nanocolloids.
  
  
  METHODS
  We studied 100 patients with early breast cancer (T1 and T2) over a 2-year period. All patients underwent deep subareolar-injection of 99mTc-nanocoloid for localization of the sentinel node. Images were obtained and when the sentinel node was seen, it was marked on the skin. All patients underwent tumor excision and radioguided SLN biopsy followed by complete lymphadenectomy. Histopathological analysis of sentinel nodes was performed by hematoxylin-eosin and immunohistochemistry with cytokeratins.
  
  
  RESULTS
  The sentinel node was identified in all patients, and a mean of 1.95 sentinel nodes per patient were found. Lymphatic metastases in the sentinel node were found in 44 patients and in 15 of these tumoral spread was also found in the remaining axillary nodes. In the 56 remaining patients the sentinel node was free of metastasis, but in two of them a non-sentinel node was found to be positive (4.5% false negative rate). Sensitivity was 95.7% (44/46), specificity was 100% (54/54), the positive predictive value was 100% and the negative predictive value was 96.4% (54/56).
  
  
  CONCLUSIONS
  SLN biopsy is an accurate alternative to complete axillary lymph node dissection in patients with early-stage breast cancer. This technique improves the staging of these patients and decreases the morbidity associated with lymphadenectomy. The advantages of subareolar injection are that a single injection site is required, the tumor does not have to be located by other techniques, it allows rapid visualization of the sentinel node and avoids the "shine through phenomenon" when the tumor is located near the axilla.
authors.affiliation: Servicio de Medicina Nuclear, Hospital Universitario Insular de Gran Canaria, Las Palmas de Gran Canaria, Canarias, Spain. faynaa@yahoo.es
authors.forename: Fayna
authors.initials: F
authors.lastname: Armas
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Hernández
authors.forename: Víctor
authors.initials: V
authors.lastname: Vega
authors.forename: Isabel
authors.initials: I
authors.lastname: Gutiérrez
authors.forename: Concepción
authors.initials: C
authors.lastname: Jiménez
authors.forename: Marta
authors.initials: M
authors.lastname: Pavcovich
authors.forename: Beatriz
authors.initials: B
authors.lastname: Báez
authors.forename: Pedro
authors.initials: P
authors.lastname: Pérez-Correa
authors.forename: Valentín
authors.initials: V
authors.lastname: Núñez
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D007267:Injections; D008875:Middle Aged; D009558:Nipples; D011877:Radionuclide Imaging; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D013668:Technetium Tc 99m Aggregated Albumin / Q000008:administration & dosage
chemical_list: D013668:Technetium Tc 99m Aggregated Albumin; C083602:technetium Tc 99m nanocolloid