Abstract
Introduction:
Symptom heterogenicity in dementia subtypes can pose diagnostic challenges, leading to potential misdiagnoses and significant implications on patient management. The NICE Guidelines for Dementia 2018 [NG97] recommend FDG-PET where diagnostic uncertainty remains after initial assessment. From 2021, a national and collaborative initiative supported using FDG-PET brain imaging for dementia in Wales to facilitate more accurate and timely diagnoses with higher degrees of confidence. This project aimed to evaluate the temporal aspects and diagnostic accuracy of FDG-PET utilization in Cardiff and Vale University Health Board.
Methods:
A retrospective review of 25 patients’ medical records who underwent FDG-PET between 2019 – 2023 was completed. Demographics, diagnostic journey details, and durations between steps were recorded. A comparison of diagnoses made at Memory Clinic (MC) and post-FDG-PET was performed. Results: The average age of patients referred for FDG-PET was 63.3 years (sd=7.69); 60% were under the age of 65 (n=15). The mean time taken from GP referral to MC review was 108.7 days (sd= 44.9). The mean duration from MC review to FDG-PET was 201.7 days (influenced by one outlier with complex presentations). The median time from MC review to FDG-PET was 71 days. The most common final diagnosis was Alzheimer’s disease, both typical and atypical subtypes. 16% (n= 4) of final diagnoses differed from initial clinical suspicion but imaging was supportive in guiding onward management. Patient outcomes depended on final diagnoses.
Conclusion:
Overall, FDG-PET supported the team in establishing a diagnosis with greater confidence, where 84% of FDG-PET outcomes were consistent with the initial working diagnosis. The recorded durations between initial review in MC and FDG-PET imaging varied considerably between individuals, however, the impression was that access to FDG-PET in Wales has supported earlier confirmation of diagnosis compared with prior practice and plays a particular role in earlier diagnosis of younger individuals.