DAT SPECT Predicts Survival in Patients Assessed for Differential Diagnosis of Dementia

Dopamine transporter (DAT) SPECT is an established diagnostic procedure in dementia diagnostics, yet its prognostic value is currently unknown.

We evaluated the prognostic value of DAT SPECT in patients assessed for differential diagnosis of dementia.

We included all patients who had received DAT SPECT for differential diagnosis of dementia from 10/2008 to 06/2016 at our site and whose survival status could be obtained in 09/2019. Clinical SPECT reports, categorizing scans into positive or negative for nigrostriatal degeneration (NSD), were tested for their prognostic value (Cox regressions, adjusted for age and sex). In addition, an automated region-of-interest analysis (striatum, occipital cortex as reference) was performed.

Median follow-up of 97 included patients was 6.6 years. Patients with NSD had a significantly higher mortality risk than those without NSD (HR = 3.6 [2.0-6.7], p < 0.001). Results were confirmed by region-of-interest analysis: higher mortality risk was associated with lower striatal DAT binding (HR = 1.8 per standard deviation loss).

Beyond its established utility in dementia diagnostics, DAT SPECT also conveys important prognostic information.