Advertisement

IMPACT OF 18F- FLORBETAPIR PET-CT ON CLINICAL DIAGNOSIS AND MANAGEMENT OF PATIENTS WITH POSSIBLE ALZHEIMER’S DISEASE

      Background

      Amyloid imaging is a relatively new technique helping establish a diagnosis of Alzheimer's disease (AD). In the UK, the use of amyloid tracers is limited by the funding arrangements within the NHS. This study was aimed to evaluate the clinical impact of 18F- Florbetapir-PET-CT on diagnosis and management of patients with high diagnostic uncertainty in community memory clinic.

      Methods

      A retrospective analysis of 13 consecutive 18F- Florbetapir-PET-CT studies was performed. Referrers were asked for an assessment of an impact on management, time between referral and diagnosis, the number of investigations performed during the diagnostic process, and whether any of them followed 18F- Florbetapir-PET-CT. Impact was classified as (a) no impact (b) confirmed proposed management or (c) altered management.

      Results

      13 patients aged between 52-74 (mean 62.5) with unclear diagnosis underwent 18F- Florbetapir-PET-CT imaging. The scan was positive for amyloid deposits in 9 out of 13 patients. Final diagnosis was AD in 9 patients, other diagnoses included frontotemporal dementia (FTDbv), traumatic encephalopathy, depression with anxiety and non-AD mild cognitive impairment (MCI). PET-CT scan had clinical impact in all cases by altering therapeutic management in 6 (46%) and confirming proposed management plan in the remaining 7 patients (53%). It was a conclusive investigation in 12 out of 13 cases. Only one person required further diagnostic tests after amyloid PET-CT (FDG-PET). The time from referral to diagnosis varied between 6 and 39 months, with the shorter intervals observed in more recently referred patients who had access to amyloid imaging. The number of the investigations, including structural imaging (MRI), FDG-PET, CSF analysis and neuropsychological assessment varied between 1 (usually MRI) to 5 (including sequential neuropsychological assessments).

      Conclusions

      This data indicates 18F- Florbetapir-PET-CT has a significant impact on the confidence of referring clinicians in all cases by altering therapeutic management in 46%, and confirming clinical impression in the others. Amyloid imaging can be a useful technique in diagnostically challenging cases where differential diagnosis includes AD in community memory clinic setting. The considerable cost of the scans may be offset by reducing the time from referral to diagnosis and the number of tests needed to confirm it.