title: Appearance of untreated bone metastases from breast cancer on FDG PET/CT: importance of histologic subtype.
abstract: OBJECTIVE
  To determine if the histology of a breast malignancy influences the appearance of untreated osseous metastases on FDG PET/CT.
  
  
  METHODS
  This retrospective study was performed under IRB waiver. Our Hospital Information System was screened for breast cancer patients who presented with osseous metastases, who underwent FDG PET/CT prior to systemic therapy or radiotherapy from 2009 to 2012. Patients with invasive ductal carcinoma (IDC), invasive lobular carcinoma (ILC), or mixed ductal/lobular (MDL) histology were included. Patients with a history of other malignancies were excluded. PET/CT was evaluated, blinded to histology, to classify osseous metastases on a per-patient basis as sclerotic, lytic, mixed lytic/sclerotic, or occult on CT, and to record SUVmax for osseous metastases on PET.
  
  
  RESULTS
  Following screening, 95 patients who met the inclusion criteria (74 IDC, 13 ILC, and 8 MDL) were included. ILC osseous metastases were more commonly sclerotic and demonstrated lower SUVmax than IDC metastases. In all IDC and MDL patients with osseous metastases, at least one was FDG-avid. For ILC, all patients with lytic or mixed osseous metastases demonstrated at least one FDG-avid metastasis; however, in only three of seven patients were sclerotic osseous metastases apparent on FDG PET.
  
  
  CONCLUSIONS
  The histologic subtype of breast cancer affects the appearance of untreated osseous metastases on FDG PET/CT. In particular, non-FDG-avid sclerotic osseous metastases were more common in patients with ILC than in patients with IDC. Breast cancer histology should be considered when interpreting non-FDG-avid sclerotic osseous lesions on PET/CT, which may be more suspicious for metastases (rather than benign lesions) in patients with ILC.
authors.affiliation: Department of Radiology, Weill Cornell Medical College, New York, NY, USA.
authors.forename: Brittany Z
authors.initials: BZ
authors.lastname: Dashevsky
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Debra A
authors.initials: DA
authors.lastname: Goldman
authors.affiliation: Department of Radiology, Weill Cornell Medical College, New York, NY, USA.
authors.forename: Molly
authors.initials: M
authors.lastname: Parsons
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Mithat
authors.initials: M
authors.lastname: Gönen
authors.affiliation: Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Adriana D
authors.initials: AD
authors.lastname: Corben
authors.affiliation: Department of Radiology, Weill Cornell Medical College, New York, NY, USA.|Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA.
authors.forename: Maxine S
authors.initials: MS
authors.lastname: Jochelson
authors.affiliation: Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Clifford A
authors.initials: CA
authors.lastname: Hudis
authors.affiliation: Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Monica
authors.initials: M
authors.lastname: Morrow
authors.affiliation: Department of Radiology, Weill Cornell Medical College, New York, NY, USA. ulanerg@mskcc.org.|Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA. ulanerg@mskcc.org.
authors.forename: Gary A
authors.initials: GA
authors.lastname: Ulaner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000556:secondary*; D001943:Breast Neoplasms / Q000473:pathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008875:Middle Aged; D064847:Multimodal Imaging; D060787:Neoplasm Grading; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D019788:Fluorodeoxyglucose F18