title: The Assessment of Estrogen Receptor Status and Its Intratumoral Heterogeneity in Patients With Breast Cancer by Using 18F-Fluoroestradiol PET/CT.
abstract: OBJECTIVE
  The aim of this study was to investigate the clinical value of F-fluoroestradiol (F-FES) PET/CT in the assessment of the estrogen receptor (ER) and its intratumoral heterogeneity in breast cancer patients.
  
  
  METHODS
  Forty-six female patients (50 lesions) with histologically confirmed invasive breast cancer who underwent both F-FES and F-FDG PET/CT in our center were retrospectively included. All the patients enrolled were scheduled to undergo biopsy. The F-FES and FDG uptakes were compared with pathological features (tumor size, ER, progesterone receptor, human epidermal growth factor receptor 2, and Ki67%). The optimal threshold to discriminate ER-positive and ER-negative lesions was determined by receiver operating characteristic curve analysis. Furthermore, we observed the intratumoral heterogeneity by a heterogeneity index (SUVmax/SUVmean) and compared the results with the Chang-Gung Image Texture Analysis.
  
  
  RESULTS
  There was good agreement between F-FES uptake and ER, progesterone receptor, and human epidermal growth factor receptor 2 expression (P < 0.001), and the use of SUVmean instead of SUVmax can provide a slightly better correlation. The optimal threshold for F-FES PET/CT to discriminate between ER-positive and ER-negative lesions, as determined by receiver operating characteristic curve analysis, was an SUVmax of 1.82 (sensitivity = 88.2% and specificity = 87.5%) and SUVmean of 1.21 (sensitivity = 85.3% and specificity = 93.7). Our simplified heterogeneity index-FES can easily observe ER heterogeneity. In addition, our results suggested that recurrent/metastatic patients and lesions located other than breast might have greater heterogeneity.
  
  
  CONCLUSIONS
  F-FES PET/CT is a feasible, noninvasive method for assessing ER expression in breast cancer patients. Because intratumoral heterogeneity exists, F-FES PET/CT might better reflect the ER expression, especially in metastatic patients after treatment, thus assisting in making individualized treatment decisions.
authors.affiliation: From the Department of Nuclear Medicine, Fudan University Shanghai Cancer Center; Department of Oncology, Shanghai Medical College, and Center for Biomedical Imaging, Fudan University; and Shanghai Engineering Research Center of Molecular Imaging Probes, Shanghai, China.
authors.forename: Zhongyi
authors.initials: Z
authors.lastname: Yang
authors.forename: Yifei
authors.initials: Y
authors.lastname: Sun
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Xu
authors.forename: Yongping
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jianping
authors.initials: J
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Xue
authors.forename: Mingwei
authors.initials: M
authors.lastname: Wang
authors.forename: Huiyu
authors.initials: H
authors.lastname: Yuan
authors.forename: Silong
authors.initials: S
authors.lastname: Hu
authors.forename: Wei
authors.initials: W
authors.lastname: Shi
authors.forename: Beiling
authors.initials: B
authors.lastname: Zhu
authors.forename: Yingjian
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000473:pathology; D004958:Estradiol / Q000031:analogs & derivatives*; D005260:Female; D005462:Fluorine Radioisotopes; D006801:Humans; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography; D012372:ROC Curve; D011960:Receptors, Estrogen / Q000378:metabolism*; D012189:Retrospective Studies
chemical_list: D005462:Fluorine Radioisotopes; D011960:Receptors, Estrogen; C062756:1-fluoroestradiol; D004958:Estradiol