title: Assessment of multifocality and axillary nodal involvement in early-stage breast cancer patients using 18F-FDG PET/CT compared to contrast-enhanced and diffusion-weighted magnetic resonance imaging and sentinel node biopsy.
abstract: BACKGROUND
  Non-invasive evaluation of the extent of axillary nodal involvement in early-stage breast cancer (ESBC) patients and accurate assessment of multifocality are both challenging. Few reports have explored whether 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) might be more useful than other diagnostic methods in these contexts.
  
  
  OBJECTIVE
  To prospectively evaluate the diagnostic utility of FDG PET/CT, contrast-enhanced, and diffusion-weighted magnetic resonance imaging (DCE-MRI and DWI), and sentinel lymph node biopsy (SNB), in detection of axillary metastatic lymph nodes in ESBC patients; and to explore the utilities of FDG PET/CT and DCE-MRI for identification of multifocality.
  
  
  METHODS
  Twenty-four female patients (mean age, 47 ± 9.9 years; range, 24-68 years) with ESBC underwent whole-body FDG PET/CT and breast MRI prior to operation. SNB and axillary lymph node dissection (ALND) were performed on all patients, as was mastectomy or wide local tumor excision. Histopathological findings served as the gold standard when evaluating either multifocality or axillary nodal involvement.
  
  
  RESULTS
  The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy, of PET/CT and DCE-MRI, used to detect multifocality, were as follows: 67% versus 78%, 100% versus 53%, 100% versus 50%, 83% versus 80%, and 88% versus 63%. SNB afforded the highest sensitivity (93%) in terms of detection of axillary metastasis. The sensitivity, NPV, and accuracy of PET/CT were 67%, 62%, and 75% respectively, thus higher than the equivalent values of either DCE-MRI or DWI.
  
  
  CONCLUSIONS
  For assessment of multifocality in ESBC patients, highly specific results of PET/CT should be taken into account along with DCE-MRI findings. For evaluation of axillary nodal involvement, PET/CT has higher sensitivity, NPV, and accuracy values than DCE-MRI and DWI and may guide a surgical decision to proceed or not to SNB or ALND.
authors.affiliation: Department of Nuclear Medicine, Bezmialem Vakif University School of Medicine, Istanbul, Turkey nurhanergul@yahoo.com.
authors.forename: Nurhan
authors.initials: N
authors.lastname: Ergul
authors.affiliation: Department of Surgery, Bezmialem Vakif University School of Medicine, Istanbul, Turkey.
authors.forename: Huseyin
authors.initials: H
authors.lastname: Kadioglu
authors.affiliation: Department of Radiology, Bezmialem Vakif University School of Medicine, Istanbul, Turkey.
authors.forename: Seyma
authors.initials: S
authors.lastname: Yildiz
authors.affiliation: Department of Radiation Oncology, Bezmialem Vakif University School of Medicine, Istanbul, Turkey.
authors.forename: Serap Baskaya
authors.initials: SB
authors.lastname: Yucel
authors.affiliation: Department of Pathology, Bezmialem Vakif University School of Medicine, Istanbul, Turkey.
authors.forename: Zuhal
authors.initials: Z
authors.lastname: Gucin
authors.affiliation: Department of Nuclear Medicine, Bezmialem Vakif University School of Medicine, Istanbul, Turkey.
authors.forename: Ezgi Basak
authors.initials: EB
authors.lastname: Erdogan
authors.affiliation: Department of Nuclear Medicine, Bezmialem Vakif University School of Medicine, Istanbul, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Aydin
authors.affiliation: Department of Surgery, Bezmialem Vakif University School of Medicine, Istanbul, Turkey.
authors.forename: Mahmut
authors.initials: M
authors.lastname: Muslumanoglu
mesh_terms: D000328:Adult; D000368:Aged; D001365:Axilla / Q000473:pathology; D001943:Breast Neoplasms / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: Breast; PET; magnetic resonance diffusion/perfusion; magnetic resonance imaging (MRI)