title: Grading of tumors and tumorlike lesions of bone: evaluation by FDG PET.
abstract: Clinical diagnosis of skeletal tumors can be difficult, because such lesions compose a large, heterogeneous group of entities with different biologic behaviors. The aim of this prospective study was to assess the value of PET in grading tumors and tumorlike lesions of bone.
  
  
  METHODS
  Two hundred two patients with suspected primary bone tumors were investigated using FDG PET. Uptake of FDG was evaluated semiquantitatively by determining the tumor-to-background ratio (T/B). All patients underwent biopsy, resulting in the histologic detection of 70 high-grade sarcomas, 21 low-grade sarcomas, 40 benign tumors, 47 tumorlike lesions, 6 osseous lymphomas, 6 plasmacytomas, and 12 metastases of an unknown primary tumor.
  
  
  RESULTS
  All lesions, with the exception of 3 benign tumors, were detected by increased FDG uptake. Although sarcomas showed significantly higher T/Bs than did latent or active benign lesions (P < 0.001), aggressive benign lesions could not be distinguished from sarcomas. Using a T/B cutoff level for malignancy of 3.0, the sensitivity of FDG PET was 93.0%, the specificity was 66.7%, and the accuracy was 81.7%.
  
  
  CONCLUSIONS
  FDG PET provides a promising tool for estimating the biologic activity of skeletal lesions, implicating consequences for the choice of surgical strategy.
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University of Ulm, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Schulte
authors.forename: D
authors.initials: D
authors.lastname: Brecht-Krauss
authors.forename: B
authors.initials: B
authors.lastname: Heymer
authors.forename: A
authors.initials: A
authors.lastname: Guhlmann
authors.forename: E
authors.initials: E
authors.lastname: Hartwig
authors.forename: M R
authors.initials: MR
authors.lastname: Sarkar
authors.forename: C G
authors.initials: CG
authors.lastname: Diederichs
authors.forename: A
authors.initials: A
authors.lastname: Von Baer
authors.forename: J
authors.initials: J
authors.lastname: Kotzerke
authors.forename: S N
authors.initials: SN
authors.lastname: Reske
mesh_terms: D000328:Adult; D001859:Bone Neoplasms / Q000000981:diagnostic imaging*; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000378:metabolism; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012509:Sarcoma / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18