title: Abdominal adipose tissue in MGUS and multiple myeloma.
abstract: OBJECTIVE
  To determine abdominal adipose tissue parameters on PET/CT in patients with monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) that may serve as predictors of progression of MGUS to MM. We hypothesized that patients with MM had higher abdominal adiposity and higher fat metabolic activity compared to patients with MGUS.
  
  
  METHODS
  Our retrospective study was IRB approved and HIPAA compliant. The study group comprised 40 patients (mean age 64 ± 13 years) with MGUS and 32 patients (mean age 62 ± 10 years) with recently diagnosed MM (mean time since diagnosis of MM 3.0 ± 3.9 months) who had not undergone MM treatment. All patients underwent whole body FDG-PET/CT. Total abdominal adipose tissue (TAT), abdominal subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) cross sectional areas (CSA) (cm(2)) and metabolic activity (SUV) were assessed. Groups were compared using ANOVA. ROC curve analysis was performed to determine cutoff values for abdominal adipose tissue parameters to detect MM.
  
  
  RESULTS
  Patients with recently diagnosed MM had higher TAT and SAT CSA (p ≤ 0.03) and higher fat metabolic activity (p < 0.01). VAT metabolic activity showed the highest sensitivity and specificity for identifying patients with MM (area under the curve 0.95 with cutoff value of >0.34, sensitivity 90.6 %, specificity 92.5 %, p < 0.0001).
  
  
  CONCLUSIONS
  Patients who were recently diagnosed with MM had higher abdominal fat CSA and higher fat metabolic activity compared to patients with MGUS. These parameters may serve as novel biomarkers of progression of MGUS to MM.
authors.affiliation: Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Yawkey 6E, 55 Fruit Street, Boston, MA, 02114, USA.
authors.forename: Joyce
authors.initials: J
authors.lastname: Veld
authors.affiliation: Division of Hematology-Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA.
authors.forename: Elizabeth K
authors.initials: EK
authors.lastname: O'Donnell
authors.affiliation: Maine Medical Center Research Institute, Scarborough, ME, 04074, USA.
authors.forename: Michaela R
authors.initials: MR
authors.lastname: Reagan
authors.affiliation: Division of Hematology-Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Yee
authors.affiliation: Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Yawkey 6E, 55 Fruit Street, Boston, MA, 02114, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Torriani
authors.affiliation: Maine Medical Center Research Institute, Scarborough, ME, 04074, USA.
authors.forename: Clifford J
authors.initials: CJ
authors.lastname: Rosen
authors.affiliation: Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Yawkey 6E, 55 Fruit Street, Boston, MA, 02114, USA. mbredella@mgh.harvard.edu.
authors.forename: Miriam A
authors.initials: MA
authors.lastname: Bredella
mesh_terms: D050153:Abdominal Fat / Q000000981:diagnostic imaging*; D050154:Adiposity; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008998:Monoclonal Gammopathy of Undetermined Significance / Q000000981:diagnostic imaging*; D009101:Multiple Myeloma / Q000000981:diagnostic imaging*; D000072078:Positron Emission Tomography Computed Tomography; D012189:Retrospective Studies
keywords: Abdominal adiposity; FDG-PET/CT; MGUS; Multiple myeloma