Evidence-based role of PET imaging in cardiac and systemic sarcoidosis: an umbrella review of the current literature

BACKGROUND: Sarcoidosis is a multisystem granulomatous disorder characterized by diverse clinical presentations and imaging findings, usually affecting the lungs and lymph nodes and skin and less commonly the heart and other organs. Positron emission tomography (PET), especially with [18F]FDG, has increasingly been used to improve the detection, risk stratification, and therapeutic monitoring of both cardiac sarcoidosis (CS) and systemic sarcoidosis (SS).METHODS: This umbrella review systematically examined published systematic reviews and meta-analyses reporting the evidence-based performance and clinical utility of PET, particularly hybrid techniques such as PET/CT for the evaluation of cardiac and systemic sarcoidosis. Multiple biomedical databases, including PubMed/MEDLINE and the Cochrane Library, were systematically searched using defined keywords related to PET imaging and sarcoidosis.RESULTS: A qualitative synthesis of the included systematic reviews and meta-analyses revealed consistent evidence supporting the application of [18F]FDG PET/CT in both cardiac and systemic sarcoidosis. Selected reviews highlighted [18F]FDG PET/CT’s value for diagnosing active disease, guiding immunosuppressive therapy, and risk stratification, especially in cardiac involvement. [18F]FDG PET/CT emerged as a valuable adjunct in evaluating suspected sarcoidosis when conventional diagnostic methods were inconclusive or insufficient.CONCLUSIONS: Evidence-based reviews consistently support the integration of [18F]FDG PET/CT for clinical decision-making in cardiac and systemic sarcoidosis, particularly for patients with unclear presentations or complex disease, for diagnosing, risk stratification and monitoring sarcoidosis. Advancing this field will require focused efforts on standardizing imaging protocols, fostering multicenter collaboration, and incorporating PET-based analyses into treatment strategies to enhance patient care and promote precision medicine in inflammatory cardiomyopathies.