Quantitative pre-clinical imaging of hypoxia and vascularity using MRI and PET.

During hypoxia, tissues are subjected to an inadequate oxygen supply, disrupting the balance needed to maintain normal function. This deficiency can occur due to reduced oxygen delivery caused by impaired blood flow or a decline in the blood's ability to carry oxygen. In tumors, hypoxia and vascularization play crucial roles, shaping their microenvironments and influencing cancer progression, response to treatment and metastatic potential.

Synthesis and stability of the [Ti]Ti-DOTA complex: en route towards aza-macrocyclic Ti-based radiopharmaceuticals.

We report the use of DOTA as a chelator for titanium. The resulting complex is fully characterised and stability studies reveal its high kinetic inertness against transmetallation and transchelation. The radiolabeling of DOTA with Ti, a guaiacol-based liquid-liquid extraction method, leads to a high radiochemical conversion up to 98%.

Current landscape and future perspectives in preclinical MR and PET imaging of brain metastasis.

Brain metastasis (BM) is a major cause of cancer patient morbidity. Clinical magnetic resonance imaging (MRI) and positron emission tomography (PET) represent important resources to assess tumor progression and treatment responses. In preclinical research, anatomical MRI and to some extent functional MRI have frequently been used to assess tumor progression.

Introduction of positron emission tomography into the Western Norwegian Health Region: Regional balance in resource utilization from 2009 to 2014.

Background: The aim was to compare resource utilization across the four health trusts within the Western Norway Regional Health Authority since the establishment of positron emission tomography (PET) at Haukeland University Hospital in Bergen in 2009.

Methods: Metadata from all PET examinations from 2009 to 2014 were automatically imported from the PET centre's central production database into a custom-developed database system, MDCake. A PET examination was defined as a procedure based on a single injection of radioactive tracer.

Default-mode network functional connectivity is closely related to metabolic activity.

Over the last decade, the brain's default-mode network (DMN) and its function has attracted a lot of attention in the field of neuroscience. However, the exact underlying mechanisms of DMN functional connectivity, or more specifically, the blood-oxygen level-dependent (BOLD) signal, are still incompletely understood. In the present study, we combined 2-deoxy-2-[(18) F]fluoroglucose positron emission tomography (FDG-PET), proton magnetic resonance spectroscopy ((1) H-MRS), and resting-state functional magnetic resonance imaging (rs-fMRI) to investigate more directly the association between local glucose consumption, local glutamatergic neurotransmission and DMN functional connectivity during rest.

Polymeric nanoparticles of FMISO: are nano-radiopharmaceuticals better than conventional ones?

Nanotechnology has been the last frontier in the diagnoses and treatment of many diseases, especially in oncology. The use of nanoparticles of radiopharmaceuticals may represent the future of Nuclear Medicine. In this study we developed, characterized and tested polymeric nanoparticles of FMISO (fluoromisonidazole) in a dynamic study of biodistribution.

Complementary but distinct roles for MRI and 18F-fluoromisonidazole PET in the assessment of human glioblastomas.

Unlabelled: Glioblastoma multiforme is a primary brain tumor known for its rapid proliferation, diffuse invasion, and prominent neovasculature and necrosis. This study explores the in vivo link between these characteristics and hypoxia by comparing the relative spatial geometry of developing vasculature inferred from gadolinium-enhanced T1-weighted MRI (T1Gd), edematous tumor extent revealed on T2-weighted MRI (T2), and hypoxia assessed by 18F-fluoromisonidazole PET (18F-FMISO). Given the role of hypoxia in upregulating angiogenic factors, we hypothesized that the distribution of hypoxia seen on 18F-FMISO is correlated spatially and quantitatively with the amount of leaky neovasculature seen on T1Gd.

Regional hypoxia in glioblastoma multiforme quantified with [18F]fluoromisonidazole positron emission tomography before radiotherapy: correlation with time to progression and survival.

Purpose: Hypoxia is associated with resistance to radiotherapy and chemotherapy and activates transcription factors that support cell survival and migration. We measured the volume of hypoxic tumor and the maximum level of hypoxia in glioblastoma multiforme before radiotherapy with [(18)F]fluoromisonidazole positron emission tomography to assess their impact on time to progression (TTP) or survival.

Experimental Design: Twenty-two patients were studied before biopsy or between resection and starting radiotherapy.

[18F]-2-fluoro-2-deoxyglucose transport kinetics as a function of extracellular glucose concentration in malignant glioma, fibroblast and macrophage cells in vitro.

FDG-PET is used to measure the metabolic rate of glucose. Transport and phosphorylation determine the amount of hexose analog that is phosphorylated and trapped. Competition occurs for both events, such that extracellular glucose concentration affects the FDG image.