[Use of positron emission tomography in sarcoidosis]

FDG-PET, now hybrid positron emission tomography/computed tomography (PET-CT), has become an established diagnostic tool in oncology. Fluorodesoxyglucose ((18)F-FDG) is not specific for malignant lesions, as uptake of the tracer depends on its accumulation in cells with an increased glucose metabolism as it is also the case in infectious and inflammatory lesions, like sarcoidosis. Thus, FDG-PET has been proposed for internal medicine indications, one of whom is sarcoidosis. The main characteristics of FDG-PET are its better sensitivity compared to (67)Ga scintigraphy and its ability to be used as an earlier marker of therapeutic response as compared with anatomy-based and conventional scintigraphic imaging. However, FDG-PET should be used in atypical or advanced stage of the disease. Future prospective studies should be awaited before integrating FDG-PET in clinical routine for treatment outcome and disease activity assessment in sarcoidosis. New radiopharmaceutical probes are under development and will improve the performance of PET.