title: Responsiveness of FDG PET/CT to treatment of patients with active chronic sarcoidosis.
abstract: OBJECTIVE
  This study aimed to compare baseline to follow-up 18F-FDG PET/CT findings after treatment for active chronic sarcoidosis and to correlate changes on 18F-FDG PET/CT with changes in clinical status.
  
  
  METHODS
  The sample included 66 patients with chronic sarcoidosis and evidence of active inflammation on baseline F-FDG PET/CT for which they received therapy. Of these 66 patients, 30 returned for the follow-up 18F-FDG PET/CT after 12 (5) months to evaluate response to treatment. They were also asked to indicate changes in clinical status. Baseline characteristics of patients who did and did not return for the follow-up were compared to assess selection bias.
  
  
  RESULTS
  SUVmax was significantly decreased at the follow-up compared with baseline 18F-FDG PET/CT (8.46 [3.52] vs 4.90 [0.96]; P = 0.006), primarily in the mediastinum. Inflammatory activity appeared absent in 9 patients, decreased in 12 patients, and increased in 9 patients, with the corresponding changes in SUVmax of -80%, -41%, and +54%, respectively. The changes on 18F-FDG PET/CT were in agreement with self-perceived changes in clinical symptoms (P = 0.019). The angiotensin-converting enzyme at the follow-up was not significantly different from baseline (49.80 [19.25] vs 46.35 [25.58], P = 0.522). There was no difference in baseline characteristics of patients who did and did not return for the follow-up.
  
  
  CONCLUSIONS
  18F-FDG PET/CT is able to detect clinically meaningful changes in magnitude and extent of inflammatory activity in patients receiving treatment for active chronic sarcoidosis. Thus, 18F-FDG PET/CT is a valuable adjunct to clinical evaluation for monitoring the response to treatment in these patients.
authors.affiliation: Faculty of Medicine, University of Belgrade, Belgrade, Serbia. dsobic2@gmail.com
authors.forename: Dragana P
authors.initials: DP
authors.lastname: Sobic-Saranovic
authors.forename: Isidora T
authors.initials: IT
authors.lastname: Grozdic
authors.forename: Jelica
authors.initials: J
authors.lastname: Videnovic-Ivanov
authors.forename: Violeta
authors.initials: V
authors.lastname: Vucinic-Mihailovic
authors.forename: Vera M
authors.initials: VM
authors.lastname: Artiko
authors.forename: Djordjije Z
authors.initials: DZ
authors.lastname: Saranovic
authors.forename: Smiljana V
authors.initials: SV
authors.lastname: Pavlovic
authors.forename: Vladimir B
authors.initials: VB
authors.lastname: Obradovic
mesh_terms: D002908:Chronic Disease; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D005500:Follow-Up Studies; D006801:Humans; D007249:Inflammation / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D012507:Sarcoidosis / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed
chemical_list: D019788:Fluorodeoxyglucose F18