Correlation between glycolytic phenotype and tumor grade in soft-tissue sarcomas by 18F-FDG PET.
Tumor glycolytic phenotyping can be accomplished with (18)F-FDG PET. Tumor (18)F-FDG uptake correlates with tumor grade in several cancers. However, the role of (18)F-FDG PET for the grading of soft-tissue sarcomas (STSs) warrants further research.


METHODS
One hundred two patients (48 men and 54 women; mean age +/- SD, 50 +/- 17 y) with 12 STS subtypes underwent (18)F-FDG PET/CT before treatment. Tumor (18)F-FDG uptake, expressed as maximum standardized uptake value (SUVmax), was compared among subtypes and correlated with histopathologic grade. Two frequently used sarcoma grading systems--the 3-tier system of the French Federation of Cancer Centers Sarcoma Group (Fédération Nationale des Centres de Lutte Contre le Cancer [FNCLCC]) and a 2-tier system (low grade vs. high grade)--were used.


RESULTS
More than 90% of STSs (93/102) exhibited a strong glycolytic phenotype (SUVmax, 2.7-52.2 g/mL). Tumor SUVmax differed significantly among tumor grades (P < 0.001 for the 3- and 2-tier grading systems). The FNCLCC and 2-tier grading systems predicted tumor grade with similar accuracy (area under the curve, 0.83 and 0.85, respectively; P = 0.35). SUVmax differed significantly among histologic subtypes (P = 0.03) in the entire population but not when high-grade STSs were analyzed separately (P = 0.31).


CONCLUSIONS
The tumor glycolytic phenotype correlated significantly with histologic grade as determined by both the FNCLCC and 2-tier (high vs. low) grading systems. (18)F-FDG PET cannot be used to reliably distinguish among grade 2 and 3 STSs (by FNCLCC) and the various subtypes.
Benz
Matthias R
MR
Department of Nuclear Medicine, University of Freiburg, Germany.
Dry
Sarah M
SM
Eilber
Fritz C
FC
Allen-Auerbach
Martin S
MS
Tap
William D
WD
Elashoff
David
D
Phelps
Michael E
ME
Czernin
Johannes
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D006019:Glycolysis / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012509:Sarcoma / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000473:pathology; D012983:Soft Tissue Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000473:pathology; D014055:Tomography, Emission-Computed; D055815:Young Adult
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18