Ziel/Aim Microglial energy demand and metabolism have gained high attention in neurodegenerative diseases. To this end, in vitro methods such as the seahorse assay are used, but it is unclear if energy metabolism of microglia highly motile in vivo is biased, when acting in vitro. Thus, we performed a direct comparison of in vivo and in vitro glucose uptake by scRadiotracing.

Somatostatin receptor positron emission tomography/computed tomography (SSTR-PET/CT) using [68Ga]-labeled tracers is a widely used imaging modality for neuroendocrine tumors (NET). Recently, [18F]SiTATE, a SiFAlin tagged [Tyr3]-octreotate (TATE) PET tracer, has shown great potential due to favorable clinical characteristics. We aimed to evaluate the reproducibility of Somatostatin Receptor-Reporting and Data System 1.0 (SSTR-RADS 1.0) for structured interpretation and treatment planning of NET using [18F]SiTATE. Four readers assessed [18F]SiTATE-PET/CT of 95 patients according to the SSTR-RADS 1.0 criteria at two different time points. Each reader evaluated up to five target lesions per scan. The overall scan score and the decision on peptide receptor radionuclide therapy (PRRT) were considered. Inter- and intra-reader agreement was determined using the intraclass correlation coefficient (ICC). The ICC analysis on the inter-reader agreement using SSTR-RADS 1.0 for identical target lesions (ICC ≥ 85

Purpose According to the World Health Organization classification for tumors of the central nervous system, mutation status of the isocitrate dehydrogenase ( IDH ) genes has become a major diagnostic discriminator for gliomas. Therefore, imaging-based prediction of IDH mutation status is of high interest for individual patient management. We compared and evaluated the diagnostic value of radiomics derived from dual positron emission tomography (PET) and magnetic resonance imaging (MRI) data to predict the IDH mutation status non-invasively. Methods Eighty-seven glioma patients at initial diagnosis who underwent PET targeting the translocator protein (TSPO) using [ 18 F]GE-180, dynamic amino acid PET using [ 18 F]FET, and T1-/T2-weighted MRI scans were examined. In addition to calculating tumor-to-background ratio (TBR) images for all modalities, parametric images quantifying dynamic [ 18 F]FET PET information were generated. Radiomic features were extracted from TBR and parametric images. The area under the receiver operating characteristic curve (AUC) was employed to assess the performance of logistic regression (LR) classifiers. To report robust estimates, nested cross-validation with five folds and 50 repeats was applied. Results TBR GE-180 features extracted from TSPO-positive volumes had the highest predictive power among TBR images (AUC 0.88, with age as co-factor 0.94). Dynamic [ 18 F]FET PET reached a similarly high performance (0.94, with age 0.96). The highest LR coefficients in multimodal analyses included TBR GE-180 features, parameters from kinetic and early static [ 18 F]FET PET images, age, and the features from TBR T2 images such as the kurtosis (0.97). Conclusion The findings suggest that incorporating TBR GE-180 features along with kinetic information from dynamic [ 18 F]FET PET, kurtosis from TBR T2 , and age can yield very high predictability of IDH mutation status, thus potentially improving early patient management.

Ziel/Aim F-18-SiTATE ist ein neuartiges F-18-markiertes, an Somatostatinrezeptoren bindendes Peptid. Dieses etablierte sich bisher in der Bildgebung von NET. Da oftmals ein alleiniges MRT die ossäre Infiltration eines Meningeoms nicht beurteilen kann, kann das F-18-SiTATE PET/CT (bisher: Ga-68 markierte Somatostatin Analoga) aufgrund der Bindungseigenschaften hierfür genutzt werden. Ziel war die Etablierung einer standardisierte Methode zur Volumenbestimmung von Meningeomen, die bis dato nicht existiert, jedoch für die Planung von OP und Radiatio von großer Relevanz ist.

Ziel/Aim TSPO PET imaging might facilitate monitoring of glioblastoma in preclinical models and patients. However, the detailed cellular and non-cellular sources of the TSPO PET signal in glioblastoma remain to be investigated. In this study, we used blocking by excessive cold ligand and subsequent cell sorting (scRadiotracing) to disentangle the magnitude of retained and blocked TSPO tracer in single cells and non-cellular compartments of glioblastoma.

Ziel/Aim Das Ziel der Studie war eine Abschätzung der Ausbeute an Doppelstrangbrüchen (DSB) und der relativen radiobiologischen Wirksamkeit (RBW) von Ac-225- und Lu-177-PSMA. Die initiale Schadensverteilung nach dem Zerfall des Radionuklids und der Restschaden nach der DNS-Reparatur wurden betrachtet.

Ziel/Aim [68Ga]Ga-FAPI-46 PET/CT is an promising modality for imaging tumor-associated fibroblasts. In squamous penile cancer, a rare tumor entity, the detection of tumor spread is essential for therapy planning. Hence, we assessed the clinical feasibility of [68Ga]Ga-FAPI-46 PET/CT in this tumor entity.