Autoradiography of Intracerebral Tumours in the Chick Embryo Model: A Feasibility Study Using Different PET Tracers.

Purpose: In addition to rodent models, the chick embryo model has gained attention for radiotracer evaluation. Previous studies have investigated tumours on the chorioallantoic membrane (CAM), but its value for radiotracer imaging of intracerebral tumours has yet to be demonstrated.

Procedures: Human U87 glioblastoma cells and U87-IDH1 mutant glioma cells were implanted into the brains of chick embryos at developmental day 5.

Identification of a metabolic brain network characterizing essential tremor.

The neuronal correlate of tremor genesis and cognitive function in essential tremor (ET) and its modulation by deep brain stimulation (DBS) are poorly understood. To explore the underlying metabolic topography of motor and cognitive symptoms, sixteen ET patients (age 63.6 ± 49.

Borderline Findings in -(2-[F]-Fluoroethyl)-l-Tyrosine PET of Patients with Suspected Glioma Relapse: Role in Clinical Practice.

One of the most common clinical indications for amino acid PET using the tracer -(2-[F]-fluoroethyl)-l-tyrosine (F-FET) is the differentiation of tumor relapse from treatment-related changes in patients with gliomas. A subset of patients may present with an uptake of F-FET close to recommended threshold values. The goal of this study was to investigate the frequency of borderline cases and the role of quantitative F-FET PET parameters in this situation.

The Value of Multidisciplinary Neuro-oncological Tumor Boards to Increase the Accuracy of FET PET for Identifying Brain Tumor Relapse.

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.

Why Current Detection of Vascular Calcification Falls Short and How to Improve on It.

Vascular calcification is a common phenomenon in various vascular diseases, where its presence heralds increased occurrence of adverse disease events, which invariably lead to increased morbidity and mortality in patients. Although the impact of calcification has become apparent, adequate and early detection of the most damaging form of early microcalcification is still in its infancy, preventing reliable identification of locations that would benefit from intervention. In this review, we will provide an overview of the current state-of-the-art noninvasive calcification imaging and its persisting limitations.

PSMA - Targeted Clinical Molecular Imaging of Atherosclerosis: Correlation with Cardiovascular Risk Factors.

Aim: The early diagnosis of atherosclerotic changes to prevent ischemic events represents a clinical challenge.Prostate-specific membrane antigen (PSMA) as an established diagnostic in the field of prostate cancer also appears to detect neovascularization and inflammation in other diseases. We hypothesized that it might be also suited for detection of inflammation in atherosclerosis.

Comparison of 2D and 3D lung lobe quantification with Ventilation/Perfusion Ratio.

In this study, standard 2D lung lobe quantification is compared with two 3D lung lobe quantification software tools to investigate the clinical benefit of a 3D approach. The accuracy of 2D versus 3D lung lobe quantification is evaluated based on the calculated numerical ventilation-perfusion ratio (VQR) using a receiver operating curve (ROC) analysis.A study group of 50 consecutive patients underwent a planar lung scintigraphy (anterior/posterior) as well as ventilation/perfusion single photon emission computed tomography (SPECT/CT) to exclude acute pulmonary embolism.

Radiosynthesis, Quality Control, and Small Animal Positron Emission Tomography Imaging of 68Ga-labelled Nano Molecules.

Small animal Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) imaging techniques are crucial in preclinical cancer research, necessitating meticulous attention to radiotracer synthesis, quality assurance, and in vivo injection protocols. This study presents a comprehensive workflow tailored to enhance the robustness and reproducibility of small animal PET experiments. The synthesis process in the radiochemistry laboratory using Ga is detailed, highlighting stringent quality control and assurance protocols for each radiotracer production.

[F]FDG whole-body PET-MR including an integrated breast MR protocol for locoregional and distant staging in breast cancer patients-a feasibility study.

Purpose: To investigate in a feasibility study the combination of [F]FDG whole-body (WB) positron emission tomography-magnetic resonance (PET-MR), including an integrated breast MR within a single protocol for locoregional and distant staging in breast cancer patients.

Methods: Consecutive patients with breast cancer diagnoses according to conventional imaging modalities (full-field digital mammography (FFDM) and ultrasound (US)) were prospectively included. All patients underwent [F]FDG WB PET-MR, including an integrated dedicated breast MR (prone position) and WB PET-MR (supine position) protocol.

Multicentric Ga-PSMA PET radiomics for treatment response assessment of Lu-PSMA-617 radioligand therapy in patients with metastatic castration-resistant prostate cancer.

Objective: The treatment with Lutetium PSMA (Lu-PSMA) in patients with metastatic castration-resistant prostate cancer (mCRPC) has recently been approved by the FDA and EMA. Since treatment success is highly variable between patients, the prediction of treatment response and identification of short- and long-term survivors after treatment could help tailor mCRPC diagnosis and treatment accordingly. The aim of this study is to investigate the value of radiomic parameters extracted from pretreatment Ga-PSMA PET images for the prediction of treatment response.

Limited Additional Value of a Chest CT in Whole-Body Staging with PET-MRI: A Retrospective Cohort Study.

Hybrid PET-MRI systems are being used more frequently. One of the drawbacks of PET-MRI imaging is its inferiority in detecting lung nodules, so it is often combined with a computed tomography (CT) of the chest. However, chest CT often detects additional, indeterminate lung nodules.

Performance evaluation of iterative PET reconstruction with resolution recovery incorporating Gallium-68 positron range correction.

Background: The distance traveled by the positron before annihilation with an electron, the so-called positron range, negatively effects the positron emission tomography (PET) image quality for radionuclides emitting high-energy positrons such as Gallium-68 (Ga).

Purpose: In this study, the effect of a tissue-independent positron range correction for Gallium-68 (Ga-PRC) was investigated based on phantom measurements. The effect of the Ga-PRC was also explored in four patients.

In Vivo Polymer Mechanochemistry with Polynucleotides.

Polymer mechanochemistry utilizes mechanical force to activate latent functionalities in macromolecules and widely relies on ultrasonication techniques. Fundamental constraints of frequency and power intensity have prohibited the application of the polymer mechanochemistry principles in a biomedical context up to now, although medical ultrasound is a clinically established modality. Here, a universal polynucleotide framework is presented that allows the binding and release of therapeutic oligonucleotides, both DNA- and RNA-based, as cargo by biocompatible medical imaging ultrasound.

MRI and F-FET PET for Multimodal Treatment Monitoring in Patients with Brain Metastases: A Cost-Effectiveness Analysis.

PET using the radiolabeled amino acid -(2-[F]fluoroethyl)-l-tyrosine (F-FET) has been shown to be of value for treatment monitoring in patients with brain metastases after multimodal therapy, especially in clinical situations with equivocal MRI findings. As medical procedures must be justified socioeconomically, we determined the effectiveness and cost-effectiveness of F-FET PET for treatment monitoring of multimodal therapy, including checkpoint inhibitors, targeted therapies, radiotherapy, and combinations thereof in patients with brain metastases secondary to melanoma or non-small cell lung cancer. We analyzed already-published clinical data and calculated the associated costs from the German statutory health insurance system perspective.

Computational Decision Support for PE Diagnosis based on Ventilation Perfusion Ratio.

Aim: The aim of this study is to investigate whether computer-aided, semi-automated 3D lung lobe quantification can support decision-making on PE diagnosis based on the ventilation-perfusion ratio in clinical practice.

Methods: A study cohort of 100 patients (39 male, 61 female, age 64.8±15.

Altered biodistribution of [Ga]Ga-DOTA-TOC during somatostatin analogue treatment.

Purpose: The need for an interval between the administration of long-acting Somatostatin Receptor Analogues (SSA) and the [Ga]Ga-DOTA-TATE PET has been questioned based on recent literature in the new EANM guidelines. Here an earlier studies showed that SSA injection immediately before SSTR PET had minimal effect on normal organ and tumor uptake (1). However, data are scarce and there are (small) differences between [Ga]Ga-DOTA-TATE and [Ga]Ga-DOTA-TOC binding affinity, and it remains unknown whether these findings can be directly translated to scans with [Ga]Ga-DOTA-TOC as well.

The prostate-specific membrane antigen holds potential as a vascular target for endogenous radiotherapy with [Lu]Lu-PSMA-I&T for triple-negative breast cancer.

Introduction: Overexpression of prostate-specific membrane antigen (PSMA) on the vasculature of triple-negative breast cancer (TNBC) presents a promising avenue for targeted endogenous radiotherapy with [Lu]Lu-PSMA-I&T. This study aimed to assess and compare the therapeutic efficacy of a single dose with a fractionated dose of [Lu]Lu-PSMA-I&T in an orthotopic model of TNBC.

Methods: Rj:NMRI-Foxn1 mice were used as recipients of MDA-MB-231 xenografts.

EANM guidance document: dosimetry for first-in-human studies and early phase clinical trials.

The numbers of diagnostic and therapeutic nuclear medicine agents under investigation are rapidly increasing. Both novel emitters and novel carrier molecules require careful selection of measurement procedures. This document provides guidance relevant to dosimetry for first-in human and early phase clinical trials of such novel agents.

Increasing striatal dopamine release through repeated bouts of theta burst transcranial magnetic stimulation of the left dorsolateral prefrontal cortex. A 18F-desmethoxyfallypride positron emission tomography study.

Introduction: Transcranial Magnetic Stimulation (TMS) can modulate fronto-striatal connectivity in the human brain. Here Positron Emission Tomography (PET) and neuro-navigated TMS were combined to investigate the dynamics of the fronto-striatal connectivity in the human brain. Employing 18F-DesmethoxyFallypride (DMFP) - a Dopamine receptor-antagonist - the release of endogenous dopamine in the striatum in response to time-spaced repeated bouts of excitatory, intermittent theta burst stimulation (iTBS) of the Left-Dorsolateral Prefrontal Cortex (L-DLPFC) was measured.

Combination of nivolumab with standard induction chemotherapy in children and adults with EBV-positive nasopharyngeal carcinoma : Protocol of a prospective multicenter phase 2 trial.

Background: Treatment of Epstein-Barr virus(EBV)-positive nasopharyngeal carcinoma (NPC) with cisplatin/5-fluorouracil (5-FU) induction chemotherapy, followed by radiochemotherapy and subsequent interferon‑β, has yielded high survival rates in children, adolescents, and young adults. A previous study has shown that reduction of radiation dose from 59.4 to 54.

Structural connectome-based predictive modeling of cognitive deficits in treated glioma patients.

Background: In glioma patients, tumor growth and subsequent treatments are associated with various types of brain lesions. We hypothesized that cognitive functioning in these patients critically depends on the maintained structural connectivity of multiple brain networks.

Methods: The study included 121 glioma patients (median age, 52 years; median Eastern Cooperative Oncology Group performance score 1; CNS-WHO Grade 3 or 4) after multimodal therapy.

Periodontal ligament and alveolar bone remodeling during long orthodontic tooth movement analyzed by a novel user-independent 3D-methodology.

The structural process of bone and periodontal ligament (PDL) remodeling during long-term orthodontic tooth movement (OTM) has not been satisfactorily described yet. Although the mechanism of bone changes in the directly affected alveolar bone has been deeply investigated, detailed knowledge about specific mechanism of PDL remodeling and its interaction with alveolar bone during OTM is missing. This work aims to provide an accurate and user-independent analysis of the alveolar bone and PDL remodeling following a prolonged OTM treatment in mice.