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

Abstract

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.

Whole-body magnetic resonance imaging in extrathoracic sarcoidosis

“…By using WB-MRI, extrathoracic organ involvement was detected in 38% of this nonselected patient group and this is in accordance with data obtained by PET/CT [8]. In agreement with previous PET studies [4,8,9], WB-MRI revealed the skeleton to be the most frequent site of extrathoracic involvement. Sarcoid muscular lesions were found in 13% of patients, supporting the assumption that muscular involvement is more frequent than clinically expected [10].…”

“…The detection of asymptomatic musculoskeletal sarcoid manifestations at WB-MRI can alter the estimation of the overall granulomatous load and disease activity, and together with the demonstrated functional impairment in patients with WB-MRI positivity, it might be speculated that WB-MRI represents a marker of total disease activity. Our findings complete previous data that demonstrated the value of PET/ CT for the assessment of disease activity in sarcoidosis [2][3][4]9], with the advantage of MRI being radiation free. Recent data suggested that PET is a predictor of pulmonary function in sarcoidosis [12]; however, the radiation exposure of PET should not be underestimated and PET is not recommended for standard workup procedures [13].…”

Sarcoidosis-associated fatigue

“…Historically, evaluation of the value of the various available tools for assessment of inflammatory activity has been hampered by the lack of a gold standard. The serological markers used are C-reactive protein, serum angiotensinconverting enzyme, soluble interleukin (IL)-2 receptor and neopterin [4,15,[42][43][44].…”

Imaging the inflammatory activity of sarcoidosis

“…After six cycles, the increase in forced expiratory volume in 1 s was 11%, and in vital capacity was 21%. [75]. In 20% of these patients, serum markers of activity were normal.…”

“…Retrospective analysis of 18 F-FDG PET/CT in symptomatic patients with stage IV disease, revealed persistent parenchymal disease activity in 14 out of 15 patients [75]. In addition, patients with increased metabolic activity in the lung parenchyma show a significant increase in VC and DL,CO after treatment [56,76].…”