Results of the Dutch ABIDE project associates PET scans to essential changes in diagnosis and treatment
Positron emission tomography (PET) to identify amyloid plaques in the brain has been extensively used in research. However, only few studies have assessed its usefulness in clinical practice. Now, a prospective diagnostic study in the Netherlands has found indication that amyloid PET, as part of a routine diagnostic work-up, can influence the diagnosis and treatment of patients with mild cognitive impairment.
According to Arno de Wilde (VU University Medical Center, Amsterdam) and colleagues participating in the ABIDE  project, offering amyloid PET imaging to all patients in a memory clinic led to a change in etiological diagnosis in 25%, and a treatment switch for 24% of those. These and further results of the study were published in the most recent issue of JAMA Neurology .
In this study, researchers offered amyloid PET with fluoride-18 Florbetaben to a total of 507 memory clinic patients as part of their routine diagnostic dementia workup (average age: 65 years; females: 39%). Pre- and post-amyloid PET diagnoses were determined for each patient, including both a clinical syndrome (dementia, mild cognitive impairment, or subjective cognitive decline) and a suspected etiology (Alzheimer’s disease or not), as well as an estimation of neurologists’ confidence in the diagnoses. Also a treatment plan was established.
The pre-test diagnoses were Alzheimer’s dementia for 32.3% of all patients; non-Alzheimer’s dementia for 13.8%; mild cognitive impairment for 22.5%; and subjective cognitive decline for 31.3%.
Following amyloid PET, which was positive for 47.7% of the patients, the pre-test etiology changed for 24.7%, more often from a negative (31%) than a positive (18%) result (P < 0.01), and the diagnostic confidence increased from 80% to 89% (P < 0.001). Moreover, neurologists altered the patient treatment post-PET in 24.3% of the cases, mainly with regards to the prescribed medication.
PET improves diagnostic accuracy
Despite some study limitations highlighted by the authors – such as a study population younger than the average Alzheimer’s disease patients, and the occurrence of fewer comorbid illnesses than in many patients with cognitive impairment in clinical practice –the research has shown that amyloid PET improves diagnostic accuracy and can help patients and families make important decisions about medications, employment, finances, and clinical trial participation.
As explained by de Wilde , the “results demonstrate that amyloid PET has important consequences, in terms of diagnosis and treatment changes, for a significant number of patients in a situation that closely resembles clinical practice. These results are an important step in bridging the gap between using amyloid PET in a research setting versus daily clinical practice”.
Performed within the frameworks of the Dutch ABIDE project, this study was supported by a ZonMW-Memorabel grant and a grant by Piramal Imaging (positron emission tomography scan costs) to the Stichting Alzheimer & Neuropsychiatrie (Amsterdam).
ABIDE (Alzheimer’s Biomarkers in Daily Practice)  is a 3-year-long project being carried out in the Netherlands. The program aims to translate the diagnostic technologies of amyloid PET, magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) from the research setting to daily clinical practice , focusing on patients with mild cognitive impairment.
[*1] de Wilde A, van Maurik IS, Kunneman M, Bouwman F, Zwan M, Willemse EA, Biessels GJ, Minkman M, Pel R, Schoonenboom NS, Smets EM, Wattjes MP, Barkhof F, Stephens A, van Lier EJ, Batrla-Utermann R, Scheltens P, Teunissen CE, van Berckel BN, van der Flier WM. Alzheimer’s biomarkers in daily practice (ABIDE) project: Rationale and design. Alzheimers Dement (Amst). 2017 Jan 23;6:143-151. eCollection 2017. PMID: 28239639.
[*2] de Wilde A, van der Flier WM, Pelkmans W, Bouwman F, Verwer J, Groot C, van Buchem MM, Zwan M, Ossenkoppele R, Yaqub M, Kunneman M, Smets EMA, Barkhof F, Lammertsma AA, Stephens A, van Lier E, Biessels GJ, van Berckel BN, Scheltens P. Association of amyloid positron emission tomography with changes in diagnosis and patient treatment in an unselected memory clinic cohort: The ABIDE Project. JAMA Neurol. 2018 Jun 11. [Epub ahead of print] PMID: 29889941.
[*3] George, J. Amyloid PET Changes Diagnosis, Treatment – Dutch study may boost prospects for insurance, Medicare coverage. MedPage Today, 2018 June 11. Available at: https://www.medpagetoday.com/neurology/alzheimersdisease/73412. Accessed on June 13, 2018.
[*4] van Maurik IS, Zwan MD, Tijms BM, Bouwman FH, Teunissen CE, Scheltens P, Wattjes MP, Barkhof F, Berkhof J, van der Flier WM; Alzheimer’s Disease Neuroimaging Initiative. Interpreting biomarker results in individual patients with mild cognitive impairment in the Alzheimer’s Biomarkers in Daily Practice (ABIDE) Project. AMA Neurol. 2017 Dec 1;74(12):1481-1491. PMID: 29049480.