Inflammatory activity assessment by F18 FDG-PET/CT in persistent symptomatic sarcoidosis

Respir Med. 2011 Dec;105(12):1917-24. doi: 10.1016/j.rmed.2011.08.012. Epub 2011 Sep 6.


Background: Establishing inflammatory activity in sarcoidosis patients with persistent disabling symptoms is important. Whole body F(18)-FDG PET/CT (PET) appeared to be a sensitive method to detect inflammatory activity in newly diagnosed symptomatic sarcoidosis. The aim was to assess the presence of inflammatory activity using PET in sarcoidosis patients with unexplained persistent disabling symptoms and the association between PET findings and serological inflammatory markers.

Methods: Sarcoidosis patients who underwent a PET between June 2005 and June 2010 (n = 89), were retrospectively included. All PET scans were examined and positive findings were classified as thoracic and/or extrathoracic. As serological markers of inflammatory activity angiotensin-converting enzyme (ACE), soluble interleukin-2 receptor (sIL-2R), and neopterin were considered.

Results: In 65/89 (73%) of the studied patients PET was positive, 52 of them (80%) had serological signs of inflammatory activity. In 14/15 patients with a Chest X-ray stage IV PET was positive. In 80% of the PET positive patients extrathoracic inflammatory activity was found. Sensitivity of combined serological inflammatory markers for the presence of inflammatory activity as detected by PET was 80%, specificity 100%, positive predictive value 100%, negative predictive value 65%.

Conclusions: The majority of sarcoidosis patients with persistent disabling symptoms, even those with radiological stage IV, had PET positive findings with remarkably 80% extrathoracic lesions. In 20% PET was positive without signs of serological inflammatory activity. PET appeared to be of additional value to assess inflammatory activity in patients with persistent symptoms in the absence of signs of serological inflammatory activity and to detect extrathoracic lesions.

Publication types

  • Evaluation Study

MeSH terms

  • Adult
  • Aged
  • Biomarkers / blood
  • Female
  • Fluorodeoxyglucose F18*
  • Humans
  • Inflammation
  • Lung Diseases / diagnostic imaging*
  • Lung Diseases / immunology
  • Male
  • Middle Aged
  • Multimodal Imaging* / methods
  • Neopterin / blood
  • Netherlands / epidemiology
  • Peptidyl-Dipeptidase A / blood
  • Positron-Emission Tomography*
  • Predictive Value of Tests
  • Quality of Life
  • Radiopharmaceuticals*
  • Receptors, Interleukin-2 / blood
  • Reproducibility of Results
  • Retrospective Studies
  • Sarcoidosis / diagnostic imaging*
  • Sarcoidosis / epidemiology
  • Sarcoidosis / immunology
  • Sensitivity and Specificity
  • Tomography, X-Ray Computed*
  • Whole Body Imaging
  • Young Adult


  • Biomarkers
  • Radiopharmaceuticals
  • Receptors, Interleukin-2
  • Fluorodeoxyglucose F18
  • Neopterin
  • Peptidyl-Dipeptidase A