News | Radiopharmaceuticals and Tracers | December 28, 2017

PET Tracer Gauges Effectiveness of Promising Alzheimer's Treatment

PET tracer helps identify ability of key enzyme to inhibit amyloid-β protein generation in mouse models

PET Tracer Gauges Effectiveness of Promising Alzheimer's Treatment

Longitudinal PET imaging with 18F-AV45. PET imaging shows the average 18F-AV45 uptake per animal group at 8 and 13 months of age. A significant interaction of genotype treatment was observed in the cortex (p = 0.0248), hippocampus (p = 0.0071) and thalamus (p = 0.0084), indicating reduced [18F]-AV45 uptake in BACE1 inhibited transgenic mice. Credit: MICA, University of Antwerp, Belgium.

December 28, 2017 — In the December featured basic science article in The Journal of Nuclear Medicine, Belgian researchers report on the first large-scale longitudinal imaging study to evaluate BACE1 inhibition with micro-PET (positron emission tomography) in mouse models of Alzheimer’s disease. PET imaging has been established as an excellent identifier of the amyloid plaque and tau tangles that characterize Alzheimer’s disease. Now it is proving to be an effective way to gauge treatment effectiveness.

The tracer makes it possible to image the effects of chronic administration of an inhibitor for an enzyme, called beta (β)-site amyloid precursor protein-cleaving enzyme 1 (BACE1), which cuts off protein fragments that can lead to amyloid-β development and is more prevalent in brains affected by Alzheimer’s. It does this by binding to BACE1.

The study compared control mice with those genetically-altered to have Alzheimer’s, and tested 18F-florbetapir (18F-AV45) along with two other tracers, 18F-FDG PET and 18F-PBR111. The mice received the BACE inhibitor at 7 weeks, then brain metabolism, neuroinflammation and amyloid-β pathology were measured using a micro-PET (μPET) scanner and each of the tracers. Baseline scans were done at 6-7 weeks and follow-up scans at 4,7 and 12 months. 18F-AV45 uptake was measured at 8 and 13 months of age. After the final scans, microscopic studies were performed.

While all three tracers detected pathological differences between the genetically modified mice and the controls, only 18F-AV45 showed the effects of inhibitor treatment by identifying reduced amyloid-β pathology in the genetically modified mice. This was confirmed in the microscopic studies.

The team of the Molecular Imaging Center Antwerp, Belgium, however warned, “This study clearly showed that accurate quantification of amyloid-beta tracers is critically important and that the non-specific uptake in the brain of subjects might be underestimated for some existing Alzheimer’s tracers that have fast metabolization profiles. The aim of this translational research is advancing results discovered at the bench so that they can be applied to patients at the bedside.”

For more information: www.jnm.snmjournals.org

Related Content

CT Offers Non-Invasive Alternative for Complex Coronary Disease Treatment Planning
News | CT Angiography (CTA) | October 16, 2018
A new study published in the European Heart Journal shows computed tomography (CT) can be a useful aid in heart team...

Images from computed tomography (CT) colonography show segmented abdominal aortic calcification measured with semiautomated CT tool on coronal image. Within region of interest over aorta selected by user, tool automatically segments and quantifies aortic calcification (shown in blue). 

Image Credit: O’Connor S D, Graffy P M, Zea R, et al. Does nonenhanced CT-based quantification of abdominal aortic calcification outperform the Framingham Risk Score in predicting cardiovascular event sin asymptomatic adults? Radiology doi: 10.1148/radiol.2018180562. Published online Oct. 2, 2018. © RSNA.

News | Computed Tomography (CT) | October 12, 2018
Computed tomography (CT)-based measures of calcification in the abdominal aorta are strong predictors of heart attacks...
CORAR Supports Medicare Diagnostic Radiopharmaceutical Payment Equity Act of 2018
News | Radiopharmaceuticals and Tracers | October 12, 2018
October 12, 2018 — The Council on Radionuclides and Radiopharmaceuticals Inc.
iCAD Announces Positive Clinical Results for Artificial Intelligence Tomosynthesis Technology
News | Mammography | October 11, 2018
iCAD Inc. announced positive clinical results of its new digital breast tomosynthesis (DBT) cancer detection software,...
Huntsman Cancer Institute Installs First Preclinical nanoScan 3T PET/MRI in U.S.
News | PET-MRI | October 10, 2018
The Center for Quantitative Cancer Imaging at Huntsman Cancer Institute (HCI) at the University of Utah in Salt Lake...
Surgery, Radiation Therapy Equally Effective in Treating Oropharyngeal Cancer
News | Radiation Therapy | October 09, 2018
A new study by researchers at UT Southwestern Medical Center found no major long-term differences in the effectiveness...
ASTRO 2018 Radiation Therapy Clinical Trials
Feature | ASTRO | October 08, 2018
October 8, 2018 — The American Society for Radiation Oncology (ASTRO) announced the 10 top-rated clinical studies tha
Adherence to Annual Lung Cancer Screening Needs Improvement
News | Lung Cancer | October 03, 2018
A study of adherence to annual low-dose computed tomography (LDCT) screening within the Veteran Health Administration...
Xoft Electronic Brachytherapy System Effective Long-Term for Early-Stage Breast Cancer
News | Brachytherapy Systems, Women's Healthcare | October 02, 2018
Breast cancer recurrence rates for patients treated with the Xoft Axxent Electronic Brachytherapy (eBx) System that...
CyberKnife System Provides Excellent Prostate Cancer Survival Rates in Five or Fewer Sessions
News | Stereotactic Body Radiation Therapy (SBRT) | September 27, 2018
Accuray Inc. announced that published data from two prospective, multi-center studies using differing protocols provide...