Dopamine Transporter (DaT) Scan Utilization in a Movement Disorder Center.

BACKGROUND: The aim of this work was to describe utilization patterns of dopamine transporter (DaT) scan and its influence on patient management at a single movement disorders center. DaT scan helps differentiate between neurodegenerative from non-neurodegenerative parkinsonism and essential tremor (ET). It has been recently approved in the United States in 2011.
METHODS: We conducted a retrospective review of all patients, observed by movement disorders neurologists, who received a DaT scan. Demographic data, medication use, and prescan diagnosis were collected.
RESULTS: A total of 216 DaT scans were performed at our center from 1 June 2011 to 31 October 2012. A total of 175 scans were included for analysis. Rates of DaT scan utilization varied from 5 to 33 per 100 new patients observed. When our specialists suspected neurodegenerative parkinsonism before the scan (N = 70), the scan was abnormal in 57%. When non-neurodegenerative parkinsonism was prescan diagnosis (N = 46), the scan was normal in 65%. When essential/dystonic tremor was suspected (N = 14), the scan was normal in 79%. When psychogenic disorder was the prescan diagnosis (N = 15), the scan was normal in only 47%. Only 4% of patients with abnormal scan remained off anti-PD medications, whereas 24% of patients with negative scan were still on anti-PD medications.
CONCLUSIONS: DaT scan utilization among specialists varied greatly. Scan results correlated most when prescan diagnosis was ET than when working diagnosis was neurodegenerative parkinsonism or other non-neurodegenerative parkinsonism. Scan result was least consistent when prescan diagnosis was psychogenic disorder. Finally, DaT scans influenced medical treatment more when it was abnormal, compared to when it was normal.