title: Do clinical, histological or immunohistochemical primary tumour characteristics translate into different (18)F-FDG PET/CT volumetric and heterogeneity features in stage II/III breast cancer?
abstract: OBJECTIVE
  The aim of this retrospective study was to determine if some features of baseline (18)F-FDG PET images, including volume and heterogeneity, reflect clinical, histological or immunohistochemical characteristics in patients with stage II or III breast cancer (BC).
  
  
  METHODS
  Included in the present retrospective analysis were 171 prospectively recruited patients with stage II/III BC treated consecutively at Saint-Louis hospital. Primary tumour volumes were semiautomatically delineated on pretreatment (18)F-FDG PET images. The parameters extracted included SUVmax, SUVmean, metabolically active tumour volume (MATV), total lesion glycolysis (TLG) and heterogeneity quantified using the area under the curve of the cumulative histogram and textural features. Associations between clinical/histopathological characteristics and (18)F-FDG PET features were assessed using one-way analysis of variance. Areas under the ROC curves (AUC) were used to quantify the discriminative power of the features significantly associated with clinical/histopathological characteristics.
  
  
  RESULTS
  T3 tumours (>5 cm) exhibited higher textural heterogeneity in (18)F-FDG uptake than T2 tumours (AUC <0.75), whereas there were no significant differences in SUVmax and SUVmean. Invasive ductal carcinoma showed higher SUVmax values than invasive lobular carcinoma (p = 0.008) but MATV, TLG and textural features were not discriminative. Grade 3 tumours had higher FDG uptake (AUC 0.779 for SUVmax and 0.694 for TLG), and exhibited slightly higher regional heterogeneity (AUC 0.624). Hormone receptor-negative tumours had higher SUV values than oestrogen receptor-positive (ER-positive) and progesterone receptor-positive tumours, while heterogeneity patterns showed only low-level variation according to hormone receptor expression. HER-2 status was not associated with any of the image features. Finally, SUVmax, SUVmean and TLG significantly differed among the three phenotype subgroups (HER2-positive, triple-negative and ER-positive/HER2-negative BCs), but MATV and heterogeneity metrics were not discriminative.
  
  
  CONCLUSIONS
  SUV parameters, MATV and textural features showed limited correlations with clinical and histopathological features. The three main BC subgroups differed in terms of SUVs and TLG but not in terms of MATV and heterogeneity. None of the PET-derived metrics offered high discriminative power.
authors.affiliation: Department of Nuclear Medicine, Saint-Louis Hospital, Paris, France.
authors.forename: David
authors.initials: D
authors.lastname: Groheux
authors.affiliation: INSERM, UMR 1101 LaTIM, CHRU Morvan, 2 avenue Foch, 29609, Brest, France.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Majdoub
authors.affiliation: DACTIM, Department of Nuclear Medicine, Milétrie Hospital, Poitiers, France.
authors.forename: Florent
authors.initials: F
authors.lastname: Tixier
authors.affiliation: DACTIM, Department of Nuclear Medicine, Milétrie Hospital, Poitiers, France.
authors.forename: Catherine Cheze
authors.initials: CC
authors.lastname: Le Rest
authors.affiliation: Department of Nuclear Medicine, Saint-Louis Hospital, Paris, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Martineau
authors.affiliation: Department of Nuclear Medicine, Saint-Louis Hospital, Paris, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Merlet
authors.affiliation: Breast Diseases Unit and Department of Medical Oncology, Saint-Louis Hospital, Paris, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Espié
authors.affiliation: Department of Pathology, Saint-Louis Hospital, Paris, France.
authors.forename: Anne
authors.initials: A
authors.lastname: de Roquancourt
authors.affiliation: Department of Nuclear Medicine, CHU Bordeaux, University of Bordeaux, Bordeaux, France.
authors.forename: Elif
authors.initials: E
authors.lastname: Hindié
authors.affiliation: INSERM, UMR 1101 LaTIM, CHRU Morvan, 2 avenue Foch, 29609, Brest, France. hatt@univ-brest.fr.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Hatt
authors.affiliation: INSERM, UMR 1101 LaTIM, CHRU Morvan, 2 avenue Foch, 29609, Brest, France.
authors.forename: Dimitris
authors.initials: D
authors.lastname: Visvikis
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011379:Prognosis; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden
chemical_list: D019788:Fluorodeoxyglucose F18