Dopamine transporter single photon emission computed tomography (DaT-SPECT) use in the diagnosis and clinical management of parkinsonism: an 8-year retrospective study

INTRODUCTION: Parkinson’s disease (PD) is a neurodegenerative movement disorder that is typically diagnosed clinically. DaT-SPECT scanning (DaT Scan) can be used when there is diagnostic difficulty differentiating from non-neurodegenerative Parkinsonism. This study assessed the effect of DaT Scan imaging on diagnosis and subsequent clinical management of these disorders. METHODS: This single-trust retrospective study involved 455 patients who had undergone DaT scans for investigation for Parkinsonism, between 01/01/2014 and 31/12/2021. Data collected included patient demographics, date of clinical assessment, scan report, pre-scan and post-scan diagnosis, and clinical management. RESULTS: The mean age at scan was 70.5 years and 57% were male. The percentage of patients who had an abnormal scan result was 40% (n = 184), whilst 53% (n = 239) had a normal scan result, and 7% (n = 32) had an equivocal scan. Pre-scan diagnosis was consistent with scan results in 71% of cases of neurodegenerative Parkinsonism, whereas this figure was 64% for cases of non-neurodegenerative Parkinsonism. For all DaT scans, the diagnosis was changed in 37% of patients (n = 168), whilst the clinical management was changed in 42% of patients (n = 190). Change in management involved 63% starting dopaminergic medication, 5% stopping dopaminergic medications, and 31% undergoing other changes in management. CONCLUSION: DaT imaging is useful for confirming the correct diagnosis and clinical management for patients with clinically indeterminate Parkinsonism. Pre-scan diagnoses were generally consistent with scan results.