title: Prospective evaluation of soft tissue masses and sarcomas using fluorodeoxyglucose positron emission tomography.
abstract: BACKGROUND
  The differentiation of soft tissue sarcoma (STS) from benign masses is difficult owing to their clinical and radiological similarities. Accurate staging is hindered by the large number of sites at which metastases may be found. This study examined the value of whole-body [18F]2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) in patients presenting with soft tissue masses.
  
  
  METHODS
  Thirty patients with a soft tissue mass suspected to be malignant were evaluated with FDG PET. The images were evaluated qualitatively and quantitatively for uptake of FDG to determine whether benign lesions could be differentiated from malignant tumours, and for the presence of metastases.
  
  
  RESULTS
  Thirty-one masses were removed from 30 patients; 12 were benign and 19 were malignant STSs. Using qualitative assessment of the FDG PET images, all the high-grade STSs (n = 12) were correctly identified, but low-grade STS (n = 7) could not be differentiated from a benign lesion. Using a quantification assessment, there was a 95 per cent sensitivity and a 75 per cent specificity in diagnosing STS. Three patients had metastases at presentation; two were correctly identified by FDG PET.
  
  
  CONCLUSIONS
  FDG PET has a role in distinguishing high-grade STS from low-grade or benign STS and may have a role in staging malignant tumours.
authors.affiliation: St Thomas' Soft Tissue Tumour Unit, London, UK.
authors.forename: J D
authors.initials: JD
authors.lastname: Lucas
authors.forename: M J
authors.initials: MJ
authors.lastname: O'Doherty
authors.forename: B F
authors.initials: BF
authors.lastname: Cronin
authors.forename: P K
authors.initials: PK
authors.lastname: Marsden
authors.forename: M A
authors.initials: MA
authors.lastname: Lodge
authors.forename: P H
authors.initials: PH
authors.lastname: McKee
authors.forename: M A
authors.initials: MA
authors.lastname: Smith
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012509:Sarcoma / Q000000981:diagnostic imaging* / Q000473:pathology; D014055:Tomography, Emission-Computed / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18