Positron emission tomography/computed tomography (PET/CT) as predictor of sarcoidosis activity: a case series

Abstract

Introduction. Sarcoidosis is a multisystemic granulomatous disease that can manifest with different clinical and radiological presentations, without specific exams to monitor activity and its spontaneous or drug-induced remission. Objective. The aim of this study was to evaluate the agreement of patients' symptoms with PET CT results in patients with sarcoidosis. Methodology and Resources. Patients with sarcoidosis underwent two PET/CT scans at two different times between 6 and 12 months to assess disease activity. The SUVmax value was noted and its agreement with the clinical status of the disease was checked. The analysis was performed using the SUVmax.  Results and Discussion. 27 patients were recruited, totaling 54 exams. The median SUVmax was 8.1 (range 3.5–16.1). Most examinations that showed hypermetabolism included lungs and other organs in the same patient. The most affected sites with uptake by PET/CT were the lungs, followed by the intra-abdominal, pelvic, and peripheral lymph nodes. Other organs with glycolytic hypermetabolism include the spleen, subcutaneous tissue, bones, and heart. There was disagreement between PET/CT scans and clinical status in 44% of patients. This occurred mainly in patients with cutaneous manifestations that exhibited no metabolic correspondence on PET/CT; patients with radiological stage IV and dyspnea not attributable to disease activity; extrapulmonary sites such as the spleen, abdominal and peripheral lymph nodes, and bone without symptoms; and patients with pulmonary uptake on PET/CT despite being asymptomatic. Conclusions. The applicability of PET/CT should be discussed for each individual case to ensure the information will aid in the patient diagnosis and management.