title: A new natural history of Charcot foot: clinical evolution and final outcome of stage 0 Charcot neuroarthropathy in a tertiary referral diabetic foot clinic.
abstract: OBJECTIVE
  The purpose of this study is to describe the usefulness of 18F-FDG PET/CT scanning in the diagnosis and follow-up of stage 0 Charcot foot (CNO) and CNO outcomes when therapeutic options are driven by this image modality.
  
  
  METHODS
  We selected 25 out of 40 diabetic patients with an acute CNO, without any bone involvement at x-ray (stage 0 CNO). Diagnostic criteria were inflammatory clinical signs of the affected foot and skin temperature difference greater than 2°C compared with the contralateral foot (ΔT). All patients underwent x-ray, MRI, and 18F-FDG PET/CT scanning (expressed as standardized uptake value, SUVmax) at baseline (T0). All patients underwent another 18F-FDG PET/CT within 1 month after ΔT was less than 2°C [clinical recovery (T1)] and again every 3 months until SUVmax was less than 2 [final recovery (T2)]; at this time, MRI confirmed the end of the inflammatory condition.
  
  
  RESULTS
  T0 ΔT was 3.04 ± 1.65°C. All patients showed T0 SUVmax of the affected foot higher than the contralateral one (3.83 ± 1.087 vs. 1.24 ± 0.3; P < 0.001). At clinical recovery (T1), defined by ΔT below 2°C, the inflammatory signs were no longer present (T0 vs. T1 ΔT = 3.04 ± 1.65 vs. 0.9 ± 0.55°C; P < 0.0001). At T1, SUVmax was unchanged from T0 (3.80 ± 1.69 vs. 3.83 ± 1.09; P = ns). At final recovery (T2), ΔT was 0.74 ± 0.29°C (similar to T1 ΔT), while the SUVmax dropped from T1 to T2 (3.8 ± 1.69 vs. 1.72 ± 0.52; P < 0.0001). Standard therapy was total contact cast and removable cast walker until T2 (15.12 ± 5.45 mo). No patient developed foot bone fractures nor had relapses during follow-up (21.75 ± 16.7 mo).
  
  
  CONCLUSIONS
  PET/CT scan allows the quantification of the inflammatory process; therefore, it may drive clinical decisions in the management of acute CNO better than clinical criteria. None of our patients developed foot bone fractures or had relapses during follow-up driven by PET/CT scan.
authors.affiliation: Policlinico Tor Vergata, Rome, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Ruotolo
authors.forename: Barbara
authors.initials: B
authors.lastname: Di Pietro
authors.forename: Laura
authors.initials: L
authors.lastname: Giurato
authors.forename: Salvatore
authors.initials: S
authors.lastname: Masala
authors.forename: Marco
authors.initials: M
authors.lastname: Meloni
authors.forename: Orazio
authors.initials: O
authors.lastname: Schillaci
authors.forename: Alberto
authors.initials: A
authors.lastname: Bergamini
authors.forename: Luigi
authors.initials: L
authors.lastname: Uccioli
mesh_terms: D017719:Diabetic Foot / Q000000981:diagnostic imaging*; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D033023:Foot Joints / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011859:Radiography; D012017:Referral and Consultation; D012881:Skin Temperature; D062606:Tertiary Care Centers; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18