The fluoroethoxy and fluoropropoxy substituted 2-(6-chloro-2-phenyl)imidazo[1,2- a]pyridin-3-yl)- N, N-diethylacetamides 8 (PBR102) and 12 (PBR111) and 2-phenyl-5,7-dimethylpyrazolo[1,5- a]pyrimidin-3-yl)- N, N-diethylacetamides 15 (PBR099) and 18 (PBR146) were synthesized and found to have high in vitro affinity and selectivity for the peripheral benzodiazepine receptors (PBRs) when compared with the central benzodiazepine receptors (CBRs). The corresponding radiolabeled compounds [ (18)F] 8 [ (18)F] 12, [ (18)F] 15, and [ (18)F] 18 were prepared from their p-toluenesulfonyl precursors in 50-85% radiochemical yield. In biodistribution studies in rats, the distribution of radioactivity of the [ (18)F]PBR compounds paralleled the known localization of PBRs. In the olfactory bulbs, where the uptake of radioactivity was higher than in the rest of the brain, PK11195 and Ro 5-4864 were able to significantly inhibit [ (18)F] 12, while little or no pharmacological action of these established PBR drugs were observed on the uptake of [ (18)F] 8, [ (18)F] 15, and [ (18)F] 18 compared to control animals. Hence, [ (18)F] 12 appeared to be the best candidate for evaluation as an imaging agent for PBR expression in neurodegenerative disorders.
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http://dx.doi.org/10.1021/jm7014556 | DOI Listing |
Clin Nucl Med
January 2025
Institute of Neuroscience and Medicine (INM-3, INM-4), Research Center Juelich, Juelich, Germany.
Purpose: Especially in Europe, amino acid PET is increasingly integrated into multidisciplinary neuro-oncological tumor boards (MNTBs) to overcome diagnostic uncertainties such as treatment-related changes. We evaluated the accuracy of MNTB decisions that included the O-(2-[18F]-fluoroethyl)-L-tyrosine (FET) PET information compared with FET PET results alone to differentiate tumor relapse from treatment-related changes.
Patients And Methods: In a single academic center, we retrospectively evaluated 180 MNTB decisions of 151 patients with CNS WHO grade 3 or 4 gliomas (n = 122) or brain metastases (n = 29) presenting equivocal MRI findings following anticancer treatment.
Mol Imaging Biol
January 2025
Department of Nuclear Medicine, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China.
Purpose: Radionuclide-labeled fibroblast activation protein inhibitor (FAPI) is an emerging tumor tracer. We sought to assess the uptake and diagnostic performance of F-FAPI-42 PET/CT compared with simultaneous 2-deoxy-2[F]fluoro-D-glucose (F-FDG) PET/CT in primary and metastatic lesions in patients with malignant digestive system neoplasms and to determine the potential clinical benefit.
Procedures: Forty-two patients (men = 30, women = 12, mean age = 56.
Eur J Nucl Med Mol Imaging
January 2025
Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-Ro 43-Gil, Songpa-Gu, Seoul, 05505, Korea.
Purpose: Estrogen receptor (ER) expression and heterogeneity affect endocrine therapy efficacy. F-fluoroestradiol (F-FES) PET/CT is an effective non-invasive method to analyze systemic ER expression. This study aimed to examine the predictive/prognostic value of F-FES PET/CT for patients treated with endocrine therapy plus cyclin-dependent kinase 4/6 (CDK4/6) inhibitors.
View Article and Find Full Text PDFJAMA Neurol
January 2025
Department of Radiology, Mayo Clinic, Rochester, Minnesota.
Importance: Although 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a well-established cross-sectional biomarker of brain metabolism in dementia with Lewy bodies (DLB), the longitudinal change in FDG-PET has not been characterized.
Objective: To investigate longitudinal FDG-PET in prodromal DLB and DLB, including a subsample with autopsy data, and report estimated sample sizes for a hypothetical clinical trial in DLB.
Design, Setting, And Participants: Longitudinal case-control study with mean (SD) follow-up of 3.
Cancer Biother Radiopharm
January 2025
Advanced Innovative Partners, Inc. (AIP), Miami, Florida, USA.
Integrin antagonist complex (IAC), a novel αvβ3 integrin antagonist peptidomimetic, has emerged as a promising agent for molecular imaging of tumor angiogenesis. This study evaluates the biodistribution and clinical efficacy of [Ga]Ga-DOTAGA-IAC PET/CT in detecting radioiodine-refractory differentiated thyroid carcinoma (RAIR-DTC), comparing its diagnostic performance with [F]F-FDG PET/CT. In this prospective pilot study, RAIR-DTC patients underwent whole-body imaging with [F] F-FDG PET/CT, followed by [Ga]Ga-DOTAGA-IAC PET/CT.
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