[123I]FP-CIT (DaTscan) SPECT Brain Imaging in Patients with Suspected Parkinsonian Syndromes

OBJECTIVE To review [123I]FP-CIT (Ioflupane I 123, DaTscan) SPECT imaging and its role in clinical practice. BACKGROUND [123I]FP-CIT is a radiopharmaceutical that binds reversibly to striatal presynaptic dopamine transporters. METHODS We review the two principal multicenter clinical trials of [123I]FP-CIT SPECT imaging and provide additional, previously unreported information. Study 1 was a trial of [123I]FP-CIT SPECT in patients with early suspected parkinsonism that compared baseline scans to the consensus clinical diagnosis established 3 years later. Study 2 was a trial of [123I]FP-CIT SPECT in patients with established diagnoses of parkinsonian syndrome (PS) or essential tremor (ET). RESULTS In Study 1, positive percent agreement (abnormal baseline scan and clinical diagnosis of PS at 36 months [n= 71]) was 78-79%. Negative percent agreement (normal baseline scan and a clinical diagnosis of non-PS at 36 months [n= 28]) was 97%. In study 2, positive percent agreement (abnormal scan and a clinical diagnosis of PS [n= 158]) was 92-97%. Negative percent agreement (normal scan and a clinical diagnosis of ET [n= 27]) was 74-96%. CONCLUSION [123I]FP-CIT SPECT brain imaging is used to assist in the evaluation of adult patients with suspected PS and may help differentiate ET from PS as an adjunct to other diagnostic evaluations.