Ioflupane I-123 (DB08824): A Comprehensive Monograph on a Radiopharmaceutical Agent for Neurodegenerative Disease Imaging

Executive Summary

Ioflupane I-123 is a small-molecule radiopharmaceutical agent that has become an indispensable tool in the field of nuclear neurology for the diagnostic evaluation of neurodegenerative disorders. It is specifically designed for the visualization of striatal dopamine transporters (DATs) using Single Photon Emission Computed Tomography (SPECT) brain imaging.[1] The core mechanism of action of Ioflupane I-123 relies on its high binding affinity for presynaptic DATs, which are transmembrane proteins integral to the regulation of synaptic dopamine. By carrying the gamma-emitting radionuclide Iodine-123 to these transporters, the agent allows for the in-vivo quantification and spatial mapping of dopaminergic neuron integrity within the brain's nigrostriatal pathway.[3] A reduction in the density of these transporters serves as a robust biomarker for the neuronal loss characteristic of certain neurodegenerative conditions.

The primary clinical indications for Ioflupane I-123 SPECT imaging are centered on its ability to aid in complex differential diagnoses. Its foundational use is in the evaluation of adult patients with suspected Parkinsonian Syndromes (PS), where it helps to distinguish tremor caused by conditions with presynaptic dopaminergic deficits (e.g., Idiopathic Parkinson's Disease, Multiple System Atrophy, Progressive Supranuclear Palsy) from Essential Tremor, a condition in which the dopaminergic system remains intact.[1] More recently, its indication has been expanded to assist in the differentiation of Dementia with Lewy Bodies (DLB) from Alzheimer's Disease (AD), a distinction with profound implications for patient management and safety.[6]