title: Prognostic value of 18F-FDG PET in monosegmental stenosis and myelopathy of the cervical spinal cord.
abstract: MRI offers perfect visualization of spondylotic stenosis of the cervical spine, but morphologic imaging does not correlate with clinical symptoms and postoperative recovery after decompression surgery. In this prospective study, we investigated the role of (18)F-FDG PET in patients with degenerative stenosis of the cervical spinal cord in relation to postsurgical outcome.
  
  
  METHODS
  Twenty patients with monosegmental spondylotic stenosis of the middle cervical spine (C3/C4 or C4/C5) showing intramedullary hyperintensity on T2-weighted MRI and clinical symptoms of myelopathy (myelopathic patients) were investigated by (18)F-FDG PET. Maximum standardized uptake values (SUV(max)) were measured at all levels of the cervical spine (C1-C7). Decompression surgery and anterior cervical fusion were performed on all patients, and clinical status (Japanese Orthopedic Association [JOA] score) was assessed before and 6 mo after surgery. The (18)F-FDG data of 10 individuals without cervical spine pathology were used as a reference (controls).
  
  
  RESULTS
  The myelopathic patients showed a significant decrease in (18)F-FDG uptake in the area of the lower cervical cord, compared with the control group (C7 SUV(max), 1.49 ± 0.18 vs. 1.71 ± 0.27, P = 0.01). Ten myelopathic patients exhibited focally increased (18)F-FDG uptake at the level of the stenosis (SUV(max), 2.27 ± 0.41 vs. 1.75 ± 0.22, P = 0.002). The remaining 10 patients showed inconspicuous (18)F-FDG uptake at the area of the stenosis. Postoperatively, the patients with focally increased (18)F-FDG accumulation at the level of stenosis showed good clinical recovery and a significant improvement in JOA scores (13.6 ± 2.3 vs. 9.5 ± 2.5, P = 0.001), whereas no significant improvement was observed in the remaining patients (JOA score, 12.0 ± 2.4 vs. 11.6 ± 2.5, not statistically significant). Multiple regression analysis identified the presence of focally increased (18)F-FDG uptake at the level of the stenosis as an independent predictor of postoperative outcome (P = 0.002).
  
  
  CONCLUSIONS
  The results suggest that regional changes in (18)F-FDG uptake have prognostic significance in compression-induced cervical myelopathy that may be helpful in decisions on the timing of surgery.
authors.affiliation: Department of Neurosurgery, Heinrich-Heine-University, Düsseldorf, Germany.
authors.forename: Frank W
authors.initials: FW
authors.lastname: Floeth
authors.forename: Gabriele
authors.initials: G
authors.lastname: Stoffels
authors.forename: Jörg
authors.initials: J
authors.lastname: Herdmann
authors.forename: Sven
authors.initials: S
authors.lastname: Eicker
authors.forename: Norbert
authors.initials: N
authors.lastname: Galldiks
authors.forename: Sascha
authors.initials: S
authors.lastname: Rhee
authors.forename: Hans-Jakob
authors.initials: HJ
authors.lastname: Steiger
authors.forename: Karl-Josef
authors.initials: KJ
authors.lastname: Langen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery*; D003627:Data Interpretation, Statistical; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000209:etiology; D019637:Orthopedic Procedures; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D019275:Radiopharmaceuticals; D012984:Software; D013117:Spinal Cord Compression / Q000000981:diagnostic imaging / Q000601:surgery; D013118:Spinal Cord Diseases / Q000000981:diagnostic imaging* / Q000601:surgery*; D013130:Spinal Stenosis / Q000000981:diagnostic imaging* / Q000601:surgery*; D016896:Treatment Outcome
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18