title: Breast cancer lymphoscintigraphy: Factors associated with sentinel lymph node non visualization.
abstract: OBJECTIVE
  To evaluate factors associated with non identification of the sentinel lymph node (SLN) in lymphoscintigraphy of breast cancer patients and analyze the relationship with SLN metastases.
  
  
  METHODS
  A single-center, cross-sectional and retrospective study was performed. Forty patients with lymphoscintigraphy without sentinel lymph node identification (negative lymphoscintigraphy - NL) were enrolled. The control group included 184 patients with SLN identification (positive lymphoscintigraphy - PL). Evaluated factors were age, body mass index (BMI), tumor size, histology, localization, preoperative breast lesion hookwire (harpoon) marking and SLN metastases. The statistical analysis was performed with uni- and multivariate logistic regression models and matched-pairs analysis.
  
  
  RESULTS
  Age (p=0.036) or having BMI (p=0.047) were the only factors significantly associated with NL. Being ≥60 years with a BMI ≥30 increased the odds of having a NL 2 and 3.8 times, respectively. Marking with hookwire seems to increase the likelihood of NL, but demonstrated statistical significance is lacking (p=0.087). The other tested variables did not affect the examination result. When controlling for age, BMI and marking with the harpoon, a significant association between lymph node metastization and NL was not found (p=0.565).
  
  
  CONCLUSIONS
  The most important factors related with non identification of SLN in the patients were age, BMI and marking with hook wire. However, only the first two had statistical importance. When these variables were controlled, no association was found between NL and axillary metastases.
authors.affiliation: Department of Nuclear Medicine of Portuguese Institute of Oncology, Lisbon Center, Portugal. Electronic address: sofiacarrilhovaz@gmail.com.
authors.forename: S C
authors.initials: SC
authors.lastname: Vaz
authors.affiliation: Department of Nuclear Medicine of Portuguese Institute of Oncology, Lisbon Center, Portugal.
authors.forename: Â
authors.initials: Â
authors.lastname: Silva
authors.affiliation: Department of Nuclear Medicine of Portuguese Institute of Oncology, Lisbon Center, Portugal.
authors.forename: R
authors.initials: R
authors.lastname: Sousa
authors.affiliation: Department of Nuclear Medicine of Portuguese Institute of Oncology, Lisbon Center, Portugal.
authors.forename: T C
authors.initials: TC
authors.lastname: Ferreira
authors.affiliation: Clinical Research Unit of Portuguese Institute of Oncology, Lisbon Center, Portugal.
authors.forename: S
authors.initials: S
authors.lastname: Esteves
authors.affiliation: Department of Nuclear Medicine of Portuguese Institute of Oncology, Lisbon Center, Portugal.
authors.forename: I P
authors.initials: IP
authors.lastname: Carvalho
authors.affiliation: Department of Nuclear Medicine of Portuguese Institute of Oncology, Lisbon Center, Portugal.
authors.forename: P
authors.initials: P
authors.lastname: Ratão
authors.affiliation: Department of Nuclear Medicine of Portuguese Institute of Oncology, Lisbon Center, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Daniel
authors.affiliation: Department of Nuclear Medicine of Portuguese Institute of Oncology, Lisbon Center, Portugal.
authors.forename: L
authors.initials: L
authors.lastname: Salgado
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D002173:Cancer Care Facilities; D003430:Cross-Sectional Studies; D005188:False Negative Reactions; D005260:Female; D057918:Fiducial Markers; D006801:Humans; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging*; D061305:Lymphoscintigraphy / Q000379:methods*; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods*; D012189:Retrospective Studies; D012307:Risk Factors; D000071036:Sentinel Lymph Node / Q000000981:diagnostic imaging*; D062606:Tertiary Care Centers; D047368:Tumor Burden
keywords: Axillary metastases; Breast cancer; Cáncer de mama; Ganglio centinela; Linfogammagrafía; Lymphoscintigraphy; Metástasis axilares; Sentinel lymph node