title: Utility of 18F-fluorodeoxy glucose and 18F-sodium fluoride positron emission tomography/computed tomography in the diagnosis of medication-related osteonecrosis of the jaw: A preclinical study in a rat model.
abstract: OBJECTIVE
  The aim of this study was to determine the clinical utility of positron emission tomography/computed tomography (PET/CT) using 18F-FDG and 18F-NaF for the diagnosis of osteonecrosis of the jaw (ONJ), by observing characteristics in rat models treated with zoledronic acid (ZA) and/or dexamethasone (DX) followed by tooth extraction.
  
  
  METHODS
  A total of 48 rats were divided randomly into four groups: Group 1, rats treated with ZA and DX; Group 2, rats treated with ZA; Group 3, rats treated with DX; and Group 4, rats treated with vehicle as normal controls. They underwent examinations with both 18F-FDG and 18F-NaF PET/CT at 4 weeks prior to tooth extraction (baseline) and 4 weeks after tooth extraction. Rats were then sacrificed to evaluate the histological incidence and characteristics of ONJ. Histological and radiological characteristics of all groups were compared to assess the effects of medication and tooth extraction.
  
  
  RESULTS
  Baseline PET/CT studies using 18F-FDG and 18F-NaF showed no difference in uptake among the groups. However, 18F-FDG PET/CT performed at 4 weeks after tooth extraction showed increased glucose metabolism at the extraction site in both the ZA/DX and the ZA-only groups compared with that in the vehicle-treated group, in accordance with the higher incidence of histological ONJ (p < 0.05, respectively). 18F-NaF PET/CT performed at 4 weeks after tooth extraction showed decreased bone uptake in the extraction site in the ZA/DX, ZA, and DX groups versus the vehicle group (all p < 0.05), but this was not correlated with the incidence of histological ONJ. The incidence of ONJ was highest in the ZA/DX group (66.7%), followed by the ZA group, both of which were significantly higher than in the DX and vehicle groups (both p < 0.05).
  
  
  CONCLUSIONS
  18F-FDG PET/CT as an inflammatory marker appeared to be a more appropriate imaging modality than 18F-NaF PET/CT in diagnosing ONJ in a rat model including a ZA/DX group. However, the decreased bone remodeling tendency highlighted by 18F-NaF PET/CT may be an indicator of a possible risk of ONJ before the onset of clinical signs and symptoms.
authors.affiliation: Department of Conservative Dentistry, Ewha Womans University School of Medicine, Seoul, South Korea.
authors.forename: Yemi
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors.forename: Ho-Young
authors.initials: HY
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Ewha Womans University School of Medicine, Seoul, South Korea.
authors.forename: Hai-Jeon
authors.initials: HJ
authors.lastname: Yoon
authors.affiliation: Department of Nuclear Medicine, Ewha Womans University School of Medicine, Seoul, South Korea. Electronic address: kbomsahn@ewha.ac.kr.
authors.forename: Bom Sahn
authors.initials: BS
authors.lastname: Kim
mesh_terms: D000818:Animals; D059266:Bisphosphonate-Associated Osteonecrosis of the Jaw; D019788:Fluorodeoxyglucose F18; D005947:Glucose; D064847:Multimodal Imaging / Q000379:methods*; D010020:Osteonecrosis; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000494:pharmacology*; D051381:Rats; D012969:Sodium Fluoride; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D012969:Sodium Fluoride; D005947:Glucose
keywords: (18)F-FDG PET/CT; (18)F-NaF; Bisphosphonate; Diagnosis; Medication-related osteonecrosis of the jaw; Rat model