The role of 18-FDG PET/CT in lung sarcoidosis

Introduction: Sarcoidosis is a multiorgan granulomatous disease of unknown etiology. 18F-fluorodeoxyglucosis positron emission tomography computed tomography (18F-FDG PET/CT) has been reported useful in the estimation of sarcoidosis activity and extent. Aim: To investigate the role of 18F-FDG PET/CT in the evaluation of intrathoracic active disease and its relationship to functional and clinical findings in pulmonary sarcoidosis patients. Material and methods: Sarcoidosis patients referred to our department between 2011 and 2016 were prospectively investigated by chest X-ray, CT, pulmonary function testing and 18F-FDG PET/CT in addition to systemic investigation. Results: 62 patients with biopsy proven sarcoidosis. All patients underwent 18F-FDG PET/CT. Median age 42 years, 54% had treatment, 63% female, 68% no/ex-smokers, Scadding radiographic stage 0, I, II, III, IV of 2,1/52,8/35/6,7/3,4, and FVC, Tiffeneau, DLCO, TLC had signs of respiratory functional impairment. Of the studied 18F-FDG PET/CT 19% had thoracic disease, 5% extrathoracic disease and 79% had both thoracic and extrathoracic disease. Concerning intrathoracic 18F-FDG PET/CT findings, bilateral hilar 63%, subcarinal 54%, subaortic lymph nodes 31% and bilateral lung parenchyma 67% were the most common sites of disease activity. Pulmonary parenchyma active disease patients expressed lower FEV1, FVC, DLCO, TLC (p Conclusion: 18F-FDG PET/CT evaluates the extent and inflammatory activity of lung sarcoidosis and was observed in 79% of patients and associated with functional and clinical parameters.