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Accurate identification of programmed cell death ligand 1 (PD-L1) expression is crucial for anti-tumor immunotherapy. However, the heterogeneity of PD-L1 expression in tumors makes it challenging to detect by immunohistochemistry. In this study, we developed two novel PD-L1 small-molecule PET tracers, [F]LGT-1 and [F]LGT-2, to enable the non-invasive and precise measurement of PD-L1 expression in tumors through PET imaging. The radiochemical yields for [F]LGT-1 and [F]LGT-2 were 12.54±2.73% and 10.54±2.21%, respectively, with both tracers exhibiting approximately 98% radiochemical purity and molar activities of 12.23±2.84 GBq/μmol and 11.41±1.47 GBq/μmol. Both tracers demonstrated good stability in PBS (pH 7.4) and mouse serum after 2 hours of incubation. In cellular uptake assays, [F]LGT-1 achieved a maximum uptake of 5.47±0.03 %AD at 4 hours, which could be significantly inhibited by the non-radioactive compound LGT-1. In contrast, [F]LGT-2 exhibited high non-specific uptake in tumor cells. PET imaging revealed that [F]LGT-1 quickly accumulated in tumors within 5 minutes, achieving an uptake of 1.48±0.15 %ID/mL, and maintained a stable level for 60 minutes, while [F]LGT-2 showed minimal tumor uptake. Additionally, [F]LGT-1 had significantly lower liver uptake compared to [F]LGT-2. Despite the high uptake in non-target tissues for [F]LGT-1, which complicates its application, this study provides new insights for developing novel PD-L1 small-molecule tracers, with further optimization of the tracers currently in progress.
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http://dx.doi.org/10.1016/j.bmcl.2025.130187 | DOI Listing |
Neurology
October 2025
Department of Radiology, Mayo Clinic, Rochester, MN.
Background And Objectives: The relationship between insomnia and cognitive decline is poorly understood. We investigated associations between chronic insomnia, longitudinal cognitive outcomes, and brain health in older adults.
Methods: From the population-based Mayo Clinic Study of Aging, we identified cognitively unimpaired older adults with or without a diagnosis of chronic insomnia who underwent annual neuropsychological assessments (z-scored global cognitive scores and cognitive status) and had quantified serial imaging outcomes (amyloid-PET burden [centiloid] and white matter hyperintensities from MRI [WMH, % of intracranial volume]).
Clin Nucl Med
September 2025
Department of Nuclear Medicine & PET/CT, Mahajan Imaging & Labs.
SCN2A gene mutations, which affect the function of the voltage-gated sodium channel NaV1.2, are associated with a spectrum of neurological disorders, including epileptic encephalopathies and autism spectrum disorders. Advanced imaging modalities such as magnetic resonance imaging (MRI) and positron emission tomography (PET) have been instrumental in elucidating the neuroanatomic and functional alterations associated with these mutations.
View Article and Find Full Text PDFCereb Cortex
August 2025
Translational Neuromodeling Unit (TNU), Institute for Biomedical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland.
Statistical Parametric Mapping (SPM) is a statistical framework and open source software package for neuroimaging data analysis. Originally created by Karl Friston in the early 1990s, it has been used by a vast number of scientific studies over the last three decades. SPM has not only revolutionized the analysis of neuroimaging data but also catalyzed the development of cognitive neuroscience.
View Article and Find Full Text PDFAnn Nucl Med
September 2025
Department of Nuclear Medicine, Marmara University School of Medicine, Istanbul, Turkey.
Objective: This study aims to systematically evaluate the inter- and intra-observer agreement regarding lesions with uncertain malignancy potential in Ga-68 PSMA PET/CT imaging of prostate cancer patients, utilizing the PSMA-RADS 2.0 classification system, and to emphasize the malignancy evidence associated with these lesions.
Methods: We retrospectively reviewed Ga-68 PSMA PET/CT images of patients diagnosed with prostate cancer via histopathology between December 2016 and November 2023.
Int J Surg
September 2025
Department of Respiratory and Critical Care Medicine, Hubei Province Clinical Research Center for Major Respiratory Diseases, Key Laboratory of Pulmonary Diseases of National Health Commission, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
Background: Precise preoperative discrimination of invasive lung adenocarcinoma (IA) from preinvasive lesions (adenocarcinoma in situ [AIS]/minimally invasive adenocarcinoma [MIA]) and prediction of high-risk histopathological features are critical for optimizing resection strategies in early-stage lung adenocarcinoma (LUAD).
Methods: In this multicenter study, 813 LUAD patients (tumors ≤3 cm) formed the training cohort. A total of 1,709 radiomic features were extracted from the PET/CT images.