title: Evaluation of chemotherapy response in primary bone tumors with F-18 FDG positron emission tomography compared with histologically assessed tumor necrosis.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the potential of positron emission tomography using F-18-fluoro-2-deoxy-D-glucose (FDG PET) to assess the chemotherapy response of primary osseous tumors compared with the degree of necrosis determined histologically.
  
  
  METHODS
  Seventeen patients with primary bone tumors (11 osteosarcomas, 6 Ewing's sarcomas) were examined using FDG PET and planar bone scintigraphy before neoadjuvant chemotherapy and before surgery. Tumor response was classified histologically according to Salzer-Kuntschik (grades I-II: good response; grades IV-VI: poor response). In both imaging methods, quantification was performed using tumor to nontumor ratios (T:NT).
  
  
  RESULTS
  Histologically, 15 patients were classified as having good responses (grade I, n = 1; grade II, n = 6; grade III, n = 8) and two as having poor responses (grades IV and V). FDG PET showed more than a 30% decrease in T:NT ratios in all patients who had good responses. However, three of these patients had increasing bone scintigraphy T:NT ratios, and another five had decreasing ratios of less than 30%. The patients with poor responses had increasing T:NT ratios and decreasing ratios of less than 30%, respectively, using both imaging methods.
  
  
  CONCLUSIONS
  FDG PET seems to be a promising tool for evaluating the response of primary osseous tumors to chemotherapy. In this preliminary study, FDG PET was superior to planar bone scintigraphy.
authors.affiliation: Department of Nuclear Medicine, University Hospital, Westfälische Wilhelms-Universität, Münster, Germany. franziu@uni-muenster.de
authors.forename: C
authors.initials: C
authors.lastname: Franzius
authors.forename: J
authors.initials: J
authors.lastname: Sciuk
authors.forename: C
authors.initials: C
authors.lastname: Brinkschmidt
authors.forename: H
authors.initials: H
authors.lastname: Jürgens
authors.forename: O
authors.initials: O
authors.lastname: Schober
mesh_terms: D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D009336:Necrosis; D012516:Osteosarcoma / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000473:pathology; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012512:Sarcoma, Ewing / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology; D014055:Tomography, Emission-Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18