title: The Comparative Study of Ultrasonography, Contrast-Enhanced MRI, and (18)F-FDG PET/CT for Detecting Axillary Lymph Node Metastasis in T1 Breast Cancer.
abstract: OBJECTIVE
  A more noninvasive evaluation of axillary lymph node in breast cancer is one of the principal challenges of breast cancer treatment. To detect axillary lymph node metastasis (ALNM) in T1 breast cancer, we have compared the axillary ultrasonography (AUS), contrast-enhanced magnetic resonance imaging (cMRI), and (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) to determine the most adequate test or a combination of tests.
  
  
  METHODS
  Retrospectively, 349 T1 breast cancer patients who were preoperatively examined using AUS, cMRI, and PET/CT between 2008 and 2011 and whom underwent pathological evaluations of axillary lymph nodes were reviewed and analyzed.
  
  
  RESULTS
  In total, 26.4% (92/349) of patients exhibited ALNM. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of AUS for determining ALNM were 44.6%, 88.7%, 58.6%, 81.7%, and 77.1%, respectively. cMRI was similar to AUS. The sensitivity, specificity, PPV, NPV, and accuracy of PET/CT were 44.5%, 94.2%, 73.2%, 82.6%, and 81.1%, respectively. The combination including cMRI and PET/CT was the most accurate with sensitivity, specificity, PPV, NPV, and accuracy values of 39.1%, 98.8%, 92.3%, 81.9%, and 83.1%, respectively. The mean number (3.5±4.2) of ALNMs in the patients who were positive based on cMRI and PET/CT and also pathologically proven to exhibit ALNM was significantly larger than the number (2.16±2.26) in other patients who exhibited ALNM (p=0.035).
  
  
  CONCLUSIONS
  There are no definitive modalities for detecting ALNM in T1 breast cancers to replace sentinel lymph node biopsy (SLNB). If ALNM is suspected based on cMRI and PET/CT, the axillary dissection without SLNB might be a better option because it is related to high possibilities of ALNM and large axillary metastatic volumes.
authors.affiliation: Department of Surgery, Kyungpook National University School of Medicine, Daegu, Korea.
authors.forename: Seung Ook
authors.initials: SO
authors.lastname: Hwang
authors.forename: Sang-Woo
authors.initials: SW
authors.lastname: Lee
authors.forename: Hye Jung
authors.initials: HJ
authors.lastname: Kim
authors.forename: Wan Wook
authors.initials: WW
authors.lastname: Kim
authors.forename: Ho Yong
authors.initials: HY
authors.lastname: Park
authors.forename: Jin Hyang
authors.initials: JH
authors.lastname: Jung
keywords: Axilla; Breast neoplasms; Diagnostic imaging; Lymph node excision; Sentinel lymph node biopsy