title: Cystic fibrosis: detecting changes in airway inflammation with FDG PET/CT.
abstract: OBJECTIVE
  To determine if fluorine 18 fluorodeoxyglucose (FDG) positron emission tomographic (PET)/computed tomographic (CT) imaging can depict a treatment effect from intravenous antibiotics for pulmonary exacerbation in cystic fibrosis (CF).
  
  
  METHODS
  The study was approved by the institutional review board of the Hospital for Sick Children and by Health Canada. Consent was obtained from all subjects. Patients with CF who were between 6 and 18 years of age and were admitted for a pulmonary exacerbation were eligible for the study. FDG PET/CT examinations (with low-dose CT) were performed on days 1 and 14 of admission (±72 hours). PET activity was quantified by using standardized uptake values (SUVs) through assessment of background activity (mean SUV [SUV(mean)]) and superimposed focal uptake (maximum SUV [SUV(max)]) for each lung zone. CT studies were scored by using the CF-CT model. SUVs from pre- and posttherapy studies were compared by using paired t tests. Unpaired t tests were used to compare data in patients with CF and data in 10 control subjects.
  
  
  RESULTS
  Twenty patients with CF were enrolled. Antibiotic therapy resulted in a significant decrease in SUV(max) (mean difference, 2.3 ± 2.1 [standard deviation], P < .0001). Pretherapy SUV(max) and SUV(mean) and posttherapy SUV(max) were significantly different from those in control subjects. The change in SUV(max) and percentage predicted forced expiratory volume in 1 second was negatively correlated. (R = -0.72, P = .004). Overall CF-CT scores significantly correlated with SUV(max) (R = 0.40, P = .01).
  
  
  CONCLUSIONS
  FDG PET/CT is a useful tool for detecting inflammatory changes resulting from treatment for pulmonary exacerbations in pediatric patients with CF. Inflammatory changes detected by using FDG PET/CT correlated with lung function, sputum neutrophil counts, and CF-CT scores. Analyzing focal lung inflammation (with SUV(max)) may be a feasible way to measure airway inflammation in patients with CF.
authors: Division of Respiratory Medicine, Department of Paediatrics, Hospital for Sick Children, University of Toronto, 555 University Ave, Toronto, ON, Canada. reshma.amin@sickkids.ca
authors: Reshma
authors: R
authors: Amin
authors: Martin
authors: M
authors: Charron
authors: Leonard
authors: L
authors: Grinblat
authors: Amer
authors: A
authors: Shammas
authors: Hartmut
authors: H
authors: Grasemann
authors: Karla
authors: K
authors: Graniel
authors: Pierluigi
authors: P
authors: Ciet
authors: Harm
authors: H
authors: Tiddens
authors: Felix
authors: F
authors: Ratjen
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002648:Child; D003550:Cystic Fibrosis / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007249:Inflammation / Q000000981:diagnostic imaging / Q000188:drug therapy; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012129:Respiratory Function Tests; D014057:Tomography, X-Ray Computed
chemical_list: D000900:Anti-Bacterial Agents; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18