Risk assessment in liposarcoma patients based on FDG PET imaging.
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.
Brenner
Winfried
W
Division of Nuclear Medicine, University of Washington Medical Center, Seattle, WA, USA. winbren_2000@yahoo.com
Eary
Janet F
JF
Hwang
Willy
W
Vernon
Cheryl
C
Conrad
Ernest U
EU
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
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18