title: The role of 18F-FDG PET/CT in staging and restaging primary bone lymphoma.
abstract: OBJECTIVE
  Primary bone lymphoma (PBL) is one of the rarest primary bone malignancies. Very limited data are available on the role of fluorine-18-fluorodeoxyglucose (F-FDG) PET/CT in PBL.
  
  
  METHODS
  Overall, 16 relevant patients had F-FDG PET/CT for staging or staging/restaging PBL. The cases with extraskeletal lesions such as lymphadenopathy or with osseous involvements in disseminated lymphoma were excluded on the basis of the definition of PBL. F-FDG PET/CT findings were correlated to pathologic and/or anatomic image information.
  
  
  RESULTS
  F-FDG PET/CT was positive with markedly increased uptake in all known PBL lesions, with a sensitivity of 100%. In 15 of 16 (93.8%) cases, the bone lesions infiltrated the adjacent soft tissue with visible soft tissue components. Except for known primary bone lesion, F-FDG PET/CT showed additional 24 bone lesions in seven patients, which accounted for 44% of all cases. With maximum standardized uptake value of 2.5 as a cutoff for differentiating residual lymphoma from metabolically inactive disease on restaging scan, the sensitivity, specificity, positive predictive value, and negative predictive value of F-FDG PET/CT for PBL were 100% (4/4), 75% (9/12), 57% (4/7), and 100% (9/9), respectively. The diagnostic accuracy of restaging F-FDG PET/CT was 81% (13/16). Two of three false-positive scans were because of post-therapeutic osteonecrosis.
  
  
  CONCLUSIONS
  F-FDG PET/CT is sensitive for showing PBL that is typically highly F-FDG avid and has the ability to depict extraskeletal soft tissue involvement and additional bone lesions on staging. More importantly, F-FDG PET/CT may accurately and reliably evaluate therapeutic response with excellent sensitivity and negative predictive value. However, false-positive F-FDG uptake poses a concern on restaging PET/CT. Post-therapeutic osteonecrosis is a potential source of false-positive findings on F-FDG PET/CT.
authors.affiliation: Department of Radiology, Nuclear Medicine Service, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA.
authors.forename: Yiyan
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008223:Lymphoma / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods* / Q000706:statistics & numerical data; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods* / Q000706:statistics & numerical data; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18