Therapeutic Consequences of Ga-PSMA-11-PET/CT in Prostate Cancer in Correlation to the Gleason Score, PSA Value, and D'Amico-Defined Risk Groups.

: The aim of this study was to demonstrate the importance of Gallium (Ga)-prostate specific membrane antigen (PSMA)-positron emissions tomography (PET)/computed tomography (CT)(PET/CT) in prostate cancer patients for therapy management with individual analyses regarding the Gleason score, prostate specific antigen (PSA) value, and the risk groups defined by D'Amico. : We retrospectively analyzed 562 Ga-PSMA-11-PET/CT examinations performed from January 2015 to March 2023 at University Hospital Marburg. We assessed treatment changes post Ga-PSMA-11-PET/CT and categorized the cases based on PSA values, Gleason scores, and D'Amico risk groups.

The impact of the xSPECT reconstruction algorithms on the recovery coefficients value for small tumors: a phantom study with 177Lu.

Quantifying small tumors is still a challenge due to the partial volume effect (PVE). Although iterative reconstruction had promising results with a better recovery coefficient (RC), it suffers from the PVE. RC values typically depend on the reconstruction method, which may affect on Lu quantifying.

Radiotracers for Imaging of Inflammatory Biomarkers TSPO and COX-2 in the Brain and in the Periphery.

Inflammation involves the activation of innate immune cells and is believed to play an important role in the development and progression of both infectious and non-infectious diseases such as neurodegeneration, autoimmune diseases, pulmonary and cancer. Inflammation in the brain is marked by the upregulation of translocator protein (TSPO) in microglia. High TSPO levels are also found, for example, in macrophages in cases of rheumatoid arthritis and in malignant tumor cells compared to their relatively low physiological expression.

In Silico and In Vitro Study towards the Rational Design of 4,4'-Disarylbisthiazoles as a Selective α-Synucleinopathy Biomarker.

The α-synucleinopathies are a group of neurodegenerative diseases characterized by the deposition of α-synuclein aggregates (α-syn) in the brain. Currently, there is no suitable tracer to enable a definitive early diagnosis of these diseases. We reported candidates based on 4,4'-disarylbisthiazole (DABTA) scaffold with a high affinity towards α-syn and excellent selectivity over Aβ and tau fibrils.

Toward Novel [F]Fluorine-Labeled Radiotracers for the Imaging of α-Synuclein Fibrils.

The accumulation of α-synuclein aggregates (α-syn) in the human brain is an occurrence common to all α-synucleinopathies. Non-invasive detection of these aggregates in a living brain with a target-specific radiotracer is not yet possible. We have recently discovered that the inclusion of a methylenedioxy group in the structure of diarylbisthiazole (DABTA)-based tracers improves binding affinity and selectivity to α-syn.

Clinical Relevance of [F]Florbetaben and [F]FDG PET/CT Imaging on the Management of Patients with Dementia.

PET of β-Amyloid plaques (Aβ) using Fflorbetaben (FFBB) and Ffluorodeoxyglucose (FFDG) increasingly aid clinicians in early diagnosis of dementia, including Alzheimer's disease (AD), frontotemporal disease, dementia with Lewy bodies, and vascular dementia. The aim of this retrospective analysis was to evaluate clinical relevance of FFBB, FFDG PET and complimentary CSF measurements in patients with suspected dementia. In this study, 40 patients with clinically suspected or history of dementia underwent (1) measurement of Aβ peptides, total tau, and p-tau protein levels in the cerebrospinal fluid (CSF) compared with healthy controls (HC); (2) clinical and neuropsychological assessment, which included Consortium to Establish a Registry for Alzheimer's Disease neuropsychological assessment battery (CERAD-NAB); (3) FFBB and FFDG PET imaging within an average of 3 weeks.

Mapping the Binding Interface of PET Tracer Molecules and Alzheimer Disease Aβ Fibrils by Using MAS Solid-State NMR Spectroscopy.

Positron emission tomography (PET) tracer molecules like thioflavin T specifically recognize amyloid deposition in brain tissue by selective binding to hydrophobic or aromatic surface grooves on the β-sheet surface along the fibril axis. The molecular basis of this interaction is, however, not well understood. We have employed magic angle spinning (MAS) solid-state NMR spectroscopy to characterize Aβ-PET tracer complexes at atomic resolution.

PET Radiopharmaceuticals for Alzheimer's Disease and Parkinson's Disease Diagnosis, the Current and Future Landscape.

Ironically, population aging which is considered a public health success has been accompanied by a myriad of new health challenges, which include neurodegenerative disorders (NDDs), the incidence of which increases proportionally to age. Among them, Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common, with the misfolding and the aggregation of proteins being common and causal in the pathogenesis of both diseases. AD is characterized by the presence of hyperphosphorylated τ protein (tau), which is the main component of neurofibrillary tangles (NFTs), and senile plaques the main component of which is β-amyloid peptide aggregates (Aβ).

Correction: F-FIBT may expand PET for β-amyloid imaging in neurodegenerative diseases.

The author listing has been updated to indicate that Timo Grimmer and Kuangyu Shi are equally contributing authors.

F-FIBT may expand PET for β-amyloid imaging in neurodegenerative diseases.

F-FIBT, 2-(p-Methylaminophenyl)-7-(2-[F]fluoroethoxy)imidazo-[2,1-b]benzothiazole, is a new selective PET tracer under clinical investigation to specifically image β-amyloid depositions (Aβ) in humans in-vivo that binds to Aβ with excellent affinity (K 0.7 ± 0.2) and high selectivity over tau and α-synuclein aggregates (Ki > 1000 nM).

Synthesis and preclinical evaluation of novel F-labeled Glu-urea-Glu-based PSMA inhibitors for prostate cancer imaging: a comparison with F-DCFPyl and F-PSMA-1007.

Background: Due to its high and consistent expression in prostate cancer (PCa), the prostate-specific membrane antigen (PSMA) represents an ideal target for molecular imaging and targeted therapy using highly specific radiolabeled PSMA ligands. To address the continuously growing clinical demand for F-labeled PSMA-probes, we developed two novel Glu-urea-Glu-(EuE)-based inhibitors, EuE-k-F-FBOA (1) and EuE-k-β-a-F-FPyl (2), both with optimized linker structure and different F-labeled aromatic moieties. The inhibitors were evaluated in a comparative preclinical study with F-DCFPyl and F-PSMA-1007.

Characterization and first human investigation of FIBT, a novel fluorinated Aβ plaque neuroimaging PET radioligand.

Imidazo[2,1-b]benzothiazoles (IBTs) are a promising novel class of amyloid positron emission tomography (PET) radiopharmaceuticals for diagnosis of neurodegenerative disorders like Alzheimer's disease (AD). Their good in vivo imaging properties have previously been shown in preclinical studies. Among IBTs, fluorinated [(18)F]FIBT was selected for further characterization and advancement toward use in humans.

Regional expansion of hypometabolism in Alzheimer's disease follows amyloid deposition with temporal delay.

Background: Cross-sectional imaging studies suggest that patterns of hypometabolism (measured by [(18)F] fluorodeoxyglucose positron emission tomography [FDG-PET]) and amyloid deposition (measured by [(11)C] Pittsburgh Compound B [PiB]- PET) in Alzheimer's disease (AD) show some overlap with each other. This indicates that neuronal dysfunction might spread within the anatomical pattern of amyloid deposition. The aim of this study was to examine longitudinal regional patterns of amyloid deposition and hypometabolism in the same population of mild AD subjects and to establish their regional relationship to each other.