title: Adipose tissue and muscle attenuation as novel biomarkers predicting mortality in patients with extremity sarcomas.
abstract: OBJECTIVE
  To assess CT-attenuation of abdominal adipose tissue and psoas muscle as predictors of mortality in patients with sarcomas of the extremities.
  
  
  METHODS
  Our study was IRB approved and HIPAA compliant. The study group comprised 135 patients with history of extremity sarcoma (mean age: 53 ± 17 years) who underwent whole body PET/CT. Abdominal subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), and psoas muscle attenuation (HU) was assessed on non-contrast, attenuation-correction CT. Clinical information including survival, tumour stage, sarcoma type, therapy and pre-existing comorbidities were recorded. Cox proportional hazard models were used to determine longitudinal associations between adipose tissue and muscle attenuation and mortality.
  
  
  RESULTS
  There were 47 deaths over a mean follow-up period of 20 ± 17 months. Higher SAT and lower psoas attenuation were associated with increased mortality (p = 0.03 and p = 0.005, respectively), which remained significant after adjustment for age, BMI, sex, tumor stage, therapy, and comorbidities (p = 0.002 and p = 0.02, respectively). VAT attenuation was not associated with mortality.
  
  
  CONCLUSIONS
  Attenuation of SAT and psoas muscle, assessed on non-contrast CT, are predictors of mortality in patients with extremity sarcomas, independent of other established prognostic factors, suggesting that adipose tissue and muscle attenuation could serve as novel biomarkers for mortality in patients with sarcomas.
  
  
  CONCLUSIONS
  • CT-attenuation of adipose tissue and muscle predict mortality in sarcoma patients • CT-attenuation predicts mortality independent of established prognostic factors • Patients with sarcomas often undergo CT for staging or surveillance • Adipose tissue and muscle attenuation could serve as biomarkers for mortality.
authors.affiliation: Division of Musculoskeletal Imaging and Intervention, 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 Musculoskeletal Imaging and Intervention, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Yawkey 6E, 55 Fruit Street, Boston, MA, 02114, USA.
authors.forename: Josephina A
authors.initials: JA
authors.lastname: Vossen
authors.affiliation: Department of Radiation Oncology, Francis H Burr Proton Therapy Center, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA.
authors.forename: Karen
authors.initials: K
authors.lastname: De Amorim Bernstein
authors.affiliation: Institute of Technology Assessment, Massachusetts General Hospital and Harvard Medical School, 101 Merrimac Street, Boston, MA, 02114, USA.
authors.forename: Elkan F
authors.initials: EF
authors.lastname: Halpern
authors.affiliation: Division of Musculoskeletal Imaging and Intervention, 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: Division of Musculoskeletal Imaging and Intervention, 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*; D015415:Biomarkers; D005121:Extremities; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D016658:Psoas Muscles / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D012509:Sarcoma / Q000000981:diagnostic imaging / Q000401:mortality*; D012983:Soft Tissue Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality*; D014057:Tomography, X-Ray Computed
chemical_list: D015415:Biomarkers
keywords: Adipose tissue attenuation; Computed tomography (CT); Hounsfield Units; Muscle attenuation; Sarcoma