title: Quantitative dynamic ¹⁸FDG-PET and tracer kinetic analysis of soft tissue sarcomas.
abstract: OBJECTIVE
  To study soft tissue sarcomas using dynamic positron emission tomography (PET) with the glucose analog tracer [(18)F]fluoro-2-deoxy-D-glucose ((18)FDG), to investigate correlations between derived PET image parameters and clinical characteristics, and to discuss implications of dynamic PET acquisition (D-PET).
  
  
  METHODS
  D-PET images of 11 patients with soft tissue sarcomas were analyzed voxel-by-voxel using a compartment tracer kinetic model providing estimates of transfer rates between the vascular, non-metabolized, and metabolized compartments. Furthermore, standard uptake values (SUVs) in the early (2 min p.i.; SUVE) and late (45 min p.i.; SUVL) phases of the PET acquisition were obtained. The derived transfer rates K1, k2 and k3, along with the metabolic rate of (18)FDG (MRFDG) and the vascular fraction νp, was fused with the computed tomography (CT) images for visual interpretation. Correlations between D-PET imaging parameters and clinical parameters, i.e. tumor size, grade and clinical status, were calculated with a significance level of 0.05.
  
  
  RESULTS
  The temporal uptake pattern of (18)FDG in the tumor varied considerably from patient to patient. SUVE peak was higher than SUVL peak for four patients. The images of the rate constants showed a systematic pattern, often with elevated intensity in the tumors compared to surrounding tissue. Significant correlations were found between SUVE/L and some of the rate parameters.
  
  
  CONCLUSIONS
  Dynamic (18)FDG-PET may provide additional valuable information on soft tissue sarcomas not obtainable from conventional (18)FDG-PET. The prognostic role of dynamic imaging should be investigated.
authors.affiliation: Department of Medical Physics, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.
authors.forename: Espen
authors.initials: E
authors.lastname: Rusten
authors.forename: Jan
authors.initials: J
authors.lastname: Rødal
authors.forename: Mona E
authors.initials: ME
authors.lastname: Revheim
authors.forename: Arne
authors.initials: A
authors.lastname: Skretting
authors.forename: Oyvind S
authors.initials: OS
authors.lastname: Bruland
authors.forename: Eirik
authors.initials: E
authors.lastname: Malinen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D012509:Sarcoma / Q000000981:diagnostic imaging*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18