Cardiac MIBG Scintigraphy in Neurodegenerative Parkinsonism: Limitations in Clinical Practice

BACKGROUND: Iodine-metaiodobenzylguanidine (MIBG) scintigraphy is a valuable tool for differentiating neurodegenerative parkinsonism but interpretation can be difficult due to comorbidities and drug-tracer interactions. OBJECTIVES: This study investigated factors limiting the clinical applicability of MIBG scintigraphy in everyday clinical practice. METHODS: Patient records (2021-2022) were retrospectively reviewed, independent of whether MIBG scintigraphy was performed, for comorbidities and concomitant medication confounding its interpretation. RESULTS: Six hundred ninety five patients (640 Parkinson's disease, 22 multiple system atrophy, 33 progressive supranuclear palsy) were included. Factors potentially influencing cardiac MIBG binding were present in 55.3% with 18.1% exhibiting multiple factors. Medications with known drug-tracer interactions were found in 46.9% and comorbidities associated with reduced cardiac MIBG uptake in 20.9%. CONCLUSIONS: The clinical utility of MIBG scintigraphy is frequently restricted by medications and comorbidities highlighting the need of careful planning in clinical practice.