title: Detection of osseous metastasis by 18F-NaF/18F-FDG PET/CT versus CT alone.
abstract: OBJECTIVE
  Sodium fluoride PET (18F-NaF) has recently reemerged as a valuable method for detection of osseous metastasis, with recent work highlighting the potential of coadministered 18F-NaF and 18F-FDG PET/CT in a single combined imaging examination. We further examined the potential of such combined examinations by comparing dual tracer 18F-NaF18/F-FDG PET/CT with CT alone for detection of osseous metastasis.
  
  
  METHODS
  Seventy-five participants with biopsy-proven malignancy were consecutively enrolled from a single center and underwent combined 18F-NaF/18F-FDG PET/CT and diagnostic CT scans. PET/CT as well as CT only images were reviewed in blinded fashion and compared with the results of clinical, imaging, or histological follow-up as a truth standard.
  
  
  RESULTS
  Sensitivity of the combined 18F-NaF/18F-FDG PET/CT was higher than that of CT alone (97.4% vs 66.7%). CT and 18F-NaF/18F-FDG PET/CT were concordant in 73% of studies. Of 20 discordant cases, 18F-NaF/18F-FDG PET/CT was correct in 19 (95%). Three cases were interpreted concordantly but incorrectly, and all 3 were false positives. A single case of osseous metastasis was detected by CT alone, but not by 18F-NaF/18F-FDG PET/CT.
  
  
  CONCLUSIONS
  Combined 18F-NaF/18F-FDG PET/CT outperforms CT alone and is highly sensitive and specific for detection of osseous metastases. The concordantly interpreted false-positive cases demonstrate the difficulty of distinguishing degenerative from malignant disease, whereas the single case of metastasis seen on CT but not PET highlights the need for careful review of CT images in multimodality studies.
authors.affiliation: From the *Department of Radiology, †Division of Nuclear Medicine, Department of Radiology, Stanford University Medical Center, Stanford, CA.
authors.forename: Srinath C
authors.initials: SC
authors.lastname: Sampath
authors.forename: Srihari C
authors.initials: SC
authors.lastname: Sampath
authors.forename: Camila
authors.initials: C
authors.lastname: Mosci
authors.forename: Amelie M
authors.initials: AM
authors.lastname: Lutz
authors.forename: Juergen K
authors.initials: JK
authors.lastname: Willmann
authors.forename: Erik S
authors.initials: ES
authors.lastname: Mittra
authors.forename: Sanjiv S
authors.initials: SS
authors.lastname: Gambhir
authors.forename: Andrei
authors.initials: A
authors.lastname: Iagaru
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000000981:diagnostic imaging*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009362:Neoplasm Metastasis / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D012680:Sensitivity and Specificity; D012969:Sodium Fluoride / Q000008:administration & dosage; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D012969:Sodium Fluoride