title: Risk assessment in liposarcoma patients based on FDG PET imaging.
abstract: OBJECTIVE
  Tumor grade and subtype are considered standard parameters for risk assessment in patients with liposarcoma. The aim of this study was to assess the clinical value of [(18)F]fluorodeoxyglucose (FDG) PET-derived maximum standardized uptake value (SUV(max)) for prediction of outcome in liposarcoma patients.
  
  
  METHODS
  (18)F-FDG PET was performed in 54 patients with liposarcoma prior to therapy. SUV(max) was calculated for each tumor and results were correlated with tumor grade, subtype, and relapse-free survival.
  
  
  RESULTS
  SUV(max) ranged from 0.4 to 15.9 (mean 3.6) and was significantly lower in grade I than in grade II and grade III tumors. SUV(max) was 2.3+/-1.7, 3.5+/-1.5, 4.8+/-2.5, and 5.6+/-5.8 in well-differentiated, myxoid/round cell, dedifferentiated, and pleomorphic subtypes, respectively. Borderline differences (p=0.059) were found between tumor SUV(max) in patients with and without relapse. Using a SUV of 3.6 as cut-off, the accuracy in predicting a relapse was 75%. Tumor grade yielded a lower accuracy for predicting relapse (50%), as did tumor subtype (35%). In Kaplan-Meier survival analysis, patients with a SUV(max) >3.6 had a significantly shorter disease-free survival of 21 months compared with 44 months in patients with a SUV(max) </=3.6. Tumor grading and tumor subtype did not yield significant differences.
  
  
  CONCLUSIONS
  Pretherapy tumor SUV obtained by FDG PET imaging was a more useful parameter for risk assessment in liposarcoma than tumor grade or subtype. A SUV(max) of more than 3.6 resulted in a significantly reduced disease-free survival and identified patients at high risk for developing early local recurrences or metastatic disease.
authors.affiliation: Division of Nuclear Medicine, University of Washington Medical Center, Seattle, WA, USA. winbren_2000@yahoo.com
authors.forename: Winfried
authors.initials: W
authors.lastname: Brenner
authors.forename: Janet F
authors.initials: JF
authors.lastname: Eary
authors.forename: Willy
authors.initials: W
authors.lastname: Hwang
authors.forename: Cheryl
authors.initials: C
authors.lastname: Vernon
authors.forename: Ernest U
authors.initials: EU
authors.lastname: Conrad
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D015994:Incidence; D008080:Liposarcoma / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D011379:Prognosis; D019275:Radiopharmaceuticals; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D014861:Washington / Q000453:epidemiology
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18