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

Area of Science:

• Nuclear medicine imaging
• Inflammatory disease diagnostics
• Sarcoidosis research

Background:

• Establishing inflammatory activity is crucial for managing persistent, disabling sarcoidosis symptoms.
• Whole body F(18)-FDG PET/CT (PET) shows promise in detecting inflammation in newly diagnosed sarcoidosis.

Purpose of the Study:

• To assess inflammatory activity using PET in sarcoidosis patients with unexplained persistent disabling symptoms.
• To evaluate the association between PET findings and serological inflammatory markers.

Main Methods:

• Retrospective analysis of 89 sarcoidosis patients who underwent PET between June 2005 and June 2010.
• Classification of PET findings into thoracic and/or extrathoracic.
• Consideration of angiotensin-converting enzyme (ACE), soluble interleukin-2 receptor (sIL-2R), and neopterin as serological inflammatory markers.

Main Results:

• PET was positive in 73% of patients; 80% of these showed serological inflammatory signs.
• PET was positive in 14/15 patients with Chest X-ray stage IV.
• 80% of PET-positive patients had extrathoracic inflammatory activity; PET sensitivity was 80% with 100% specificity for serological markers.

Conclusions:

• The majority of sarcoidosis patients with persistent symptoms, including stage IV, had positive PET findings, with 80% showing extrathoracic lesions.
• PET identified inflammatory activity in 20% of patients without serological inflammatory markers.
• PET is valuable for assessing inflammatory activity and detecting extrathoracic lesions in sarcoidosis, especially when serological markers are inconclusive.