Publications by authors named "M Tonietto"

Alzheimer disease (AD) is characterized by the accumulation of tau neurofibrillary tangles that can be labeled with PET tracers. Multiple tau PET tracers have been used in clinical studies, including [F]GTP1, [F]PI-2620, and [F]MK-6240. Standardized harmonization scales for comparing tau PET signals across tracers are currently under development and can be informed by comparisons of signals between tracers in both target and off-target regions of the brain.

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Background: Second-generation tau tracers for positron emission tomography (PET) show high affinity for paired helical filaments tau deposits characteristic of Alzheimer´s disease and low off-target binding. Differences in their chemical structure though may lead to variations in their regional tau uptake and off-target signal. In this work, we aimed to compare the in-vivo uptake of tau tracers [F]PI-2620 and [F]RO948 in the early stages of the AD continuum.

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Introduction: Tau-positron emission tomography (PET) outcome data of patients with Alzheimer's disease (AD) cannot currently be meaningfully compared or combined when different tracers are used due to differences in tracer properties, instrumentation, and methods of analysis.

Methods: Using head-to-head data from five cohorts with tau PET radiotracers designed to target tau deposition in AD, we tested a joint propagation model (JPM) to harmonize quantification (units termed "CenTauR" [CTR]). JPM is a statistical model that simultaneously models the relationships between head-to-head and anchor point data.

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Article Synopsis
  • The study aimed to evaluate the relationship between oxygen supply and myelin damage in the brain by simultaneously measuring myelin and cerebral blood flow (CBF) using dynamic [11C]PiB PET scans.* -
  • Eight healthy subjects underwent two PET scans to compare three quantitative analysis methods for CBF and myelin content, focusing on the impact of region size and assessing reproducibility and intercorrelations between metrics.* -
  • Results indicated that the SRTM2 method was the most reliable for CBF measurement in white matter, showing lower blood flow in white compared to grey matter and revealing important interactions between region size and measurement reliability.*
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Background: Monoclonal antibodies that target amyloid-beta and remove amyloid plaques can slow cognitive and functional decline in early Alzheimer's disease. Gantenerumab is a subcutaneously administered fully-human anti-amyloid-beta monoclonal antibody with highest affinity for aggregated amyloid-beta. Since the phase 3 GRADUATE trials did not meet the primary endpoint (change from baseline to Week 116 in Clinical Dementia Rating scale - Sum of Boxes), development of gantenerumab in sporadic Alzheimer's disease was stopped and all ongoing trials were terminated early due to sponsor decision.

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