title: Determinants of diagnostic performance of [F-18]fluorodeoxyglucose positron emission tomography for axillary staging in breast cancer.
abstract: OBJECTIVE
  To prospectively investigate determinants of the accuracy of staging axillary lymph nodes in breast cancer using [F-18]fluorodeoxyglucose positron emission tomography (FDG PET).
  
  
  METHODS
  Patients with primary operable breast cancer underwent FDG PET of the chest followed by sentinel node biopsy (SNB, n = 47) and/or complete axillary lymph node dissection (ALND, n = 23). PET scans were independently interpreted by three observers in a blinded fashion with respect to the FDG avidity of the primary tumor and the axillary status. The results were compared to histopathological analyses of the axillary lymph nodes. Clinicians were blinded to the PET results.
  
  
  RESULTS
  Axillary lymph node specimens and FDG PET scans were evaluated in 70 patients (59% cT1). Overall, 32 (46%) had lymph node metastases as established by SNB (18/47) or ALND (14/23), 20 of which were confined to a single node. The overall sensitivity of FDG PET was 25%, with a specificity of 97%. PET results were false-negative in all 18 positive SNBs and true-positive in 8/14 in the ALND group. The performance of FDG PET depended on the axillary tumor load and the FDG avidity of the primary tumor. Intense uptake in the primary tumor was found in only 57% of the patients, and this was independent of the size. There was excellent interobserver agreement of visual assessment of FDG uptake in primary tumor and axillary lymph nodes.
  
  
  CONCLUSIONS
  The sensitivity of FDG PET to detect occult axillary metastases in operable breast cancer was low, and it was a function of axillary tumor load and FDG avidity of the primary tumor. Even though the clinical relevance of occult disease detected by SNB needs to be confirmed, it is suggested that FDG PET in these patients should be focused on exploiting its nearly perfect specificity and the potential prognostic relevance of variable FDG uptake.
authors.affiliation: Departments of Internal Medicine and Surgery, Ziekenhuis Amstelveen, Amstelveen, The Netherlands. jjho@zha.nl
authors.forename: Jacobus J M
authors.initials: JJ
authors.lastname: van der Hoeven
authors.forename: Otto S
authors.initials: OS
authors.lastname: Hoekstra
authors.forename: Emile F I
authors.initials: EF
authors.lastname: Comans
authors.forename: Rik
authors.initials: R
authors.lastname: Pijpers
authors.forename: Robert P A
authors.initials: RP
authors.lastname: Boom
authors.forename: Dick
authors.initials: D
authors.lastname: van Geldere
authors.forename: Sybren
authors.initials: S
authors.lastname: Meijer
authors.forename: Adriaan A
authors.initials: AA
authors.lastname: Lammertsma
authors.forename: Gerrit J J
authors.initials: GJ
authors.lastname: Teule
mesh_terms: D001365:Axilla; D001943:Breast Neoplasms / Q000473:pathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy; D014055:Tomography, Emission-Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18