Analysis of hypoxia in human glioblastoma tumors with dynamic 18F-FMISO PET imaging

AbstractGliomas are the most common type of primary brain tumors and are classified as grade IV. Necrosis and hypoxia are essential diagnostic features which result in poor prognosis of gliomas. The aim of this study was to report quantitative temporal analyses aiming at determining the hypoxic regions in glioblastoma multiforme and to suggest an optimal time for the clinical single scan of hypoxia. Nine subjects were imaged with PET and 18F-FMISO in dynamic mode for 15  min followed with static scans at 2, 3 and 4 h post-injection. Spectral analysis, tumor-to-blood ratio (TBR) and tumor-to-normal tissue ratio (TNR) were used to delimit perfused and hypoxic tumor regions. TBR and TNR images were further scaled by thresholding at 1.2, 1.4, 2 and 2.5 levels. The im ages showed a varying tumor volume with time. TBR produced broader images of the tumor than TNR considering the same thresholds on intensity. Spectral analysis reliably determined hypoxia with different degrees of perfusion. By comparing TBR and TNR with spectral analysis images, weak to moderate co rrelation coefficients were found for most thresholding values and imaging times (range: 0 to 0.69). Hypoxic volume (HV) estimated from the net uptake rate (Ki) were changing among imaging times. The minimum HV changes were found between 3  h and 4 h, confirming that after 3 h, there was a very low exchange of 81F-FMISO between blood and tumor. On the other hand, hypoxia started to dominate the pe...
Source: Australasian Physical and Engineering Sciences in Medicine - Category: Biomedical Engineering Source Type: research

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CONCLUSION: A multivariate prediction model created using blood flow, vascular permeability, and glycometabolism parameters can predict the extent of hypoxia in FMISO-positive areas in patients with brain tumors. PMID: 31611541 [PubMed - as supplied by publisher]
Source: Magnetic Resonance in Medical Sciences : MRMS - Category: Radiology Authors: Tags: Magn Reson Med Sci Source Type: research
Abstract13N-Ammonia (13N-NH3) is widely used positron emission tomography/computed tomography (PET/CT) radiotracer for the measurement of myocardial blood perfusion; the possible role of13N-NH3 PET or PET/CT in oncological disease is not yet clear. Aim of this review is to evaluate the diagnostic performances of13N-NH3 PET in this field. A comprehensive computer literature search of the PubMed/MEDLINE, Scopus, and Embase databases was conducted including articles up to June 2019. Eighteen articles were finally included in the review. From the analyses of the selected studies, the following main findings could be drawn: (1)...
Source: Japanese Journal of Radiology - Category: Radiology Source Type: research
CONCLUSIONS: A positive linear correlation between CBV and acidity in areas of T2-hyperintense, nonenhancing tumor, but not enhancing tumor, was observed across patients. Local heterogeneity was observed within individual tumors.
Source: American Journal of Neuroradiology - Category: Radiology Authors: Tags: FUNCTIONAL Source Type: research
Conclusions: This study presents the comparison of a voxel based analysis of 18F-DOPA PET/CT and MRI in glioma patients. The mismatch between 18F-DOPA and MRI parameters indirectly confirms the hypothesis of different biological parameters identified by 18F-DOPA and MRI. Acknowledgement: This study supported by funding from the Science Development Foundation under the President of the Republic of Azerbaijan [Grant EIF/GAM-4-BGM-GIN-2017-3(29)-19/13/3]
Source: Journal of Nuclear Medicine - Category: Nuclear Medicine Authors: Tags: Brain Imaging Reloaded II Source Type: research
Chiu-Min Lin1†, Ching-Fang Yu2,3†, Hsueh-Ya Huang1,4, Fang-Hsin Chen2,3,5, Ji-Hong Hong2,3,5 and Chi-Shiun Chiang1,6,7* 1Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan 2Department of Radiation Oncology, Chang Gung Memorial Hospital Linkou Branch, Taoyuan, Taiwan 3Radiation Biology Research Center, Institute for Radiological Research, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan 4Education &Medical Research National Taiwan University Hospital Hsin-Chu Branch, Hsinchu, Taiwan 5Department of Medical Imaging an...
Source: Frontiers in Oncology - Category: Cancer & Oncology Source Type: research
rt Galldiks Imaging techniques such as positron emission tomography (PET) and magnetic resonance imaging (MRI) provide valuable information about brain tumor patients. Particularly amino acid PET, advanced MRI techniques, and combinations thereof are of great interest for the non-invasive assessment of biological characteristics in patients with primary or secondary brain cancer. A methodological innovation that potentially advances research in patients with brain tumors is the increasing availability of hybrid PET/MRI systems, which enables the simultaneous acquisition of both imaging modalities. Furthermore, the adve...
Source: Cancers - Category: Cancer & Oncology Authors: Tags: Review Source Type: research
The aims of this study were to implement a magnetic resonance spectroscopy (MRS) protocol for the online profiling of subnanomolar quantities of metabolites sampled from the extracellular fluid using implanted microdialysis and to apply this protocol in glioma‐bearing rats for the quantification of lactate concentration and the measurement of time‐varying lactate concentration during drug administration. MRS acquisitions on the brain microdialysate were performed using a home‐built, proton‐tuned, microsolenoid with an active volume of 2 μL. The microcoil was placed at the outlet of the microdialysis probe i...
Source: NMR in Biomedicine - Category: Radiology Authors: Tags: RESEARCH ARTICLE Source Type: research
ConclusionsBoth18F –FET PET and PWI discriminate LGG from HGG with similar diagnostic performance. Regional abnormalities in the tumor area are usually not congruent indicating that tumor grading by18F –FET PET and PWI is based on different pathophysiological phenomena.
Source: European Journal of Nuclear Medicine and Molecular Imaging - Category: Nuclear Medicine Source Type: research
ConclusionWhole-tumor histogram analysis of CBV map provides more valuable histogram parameters and increases diagnostic accuracy in the differentiation of pre-operative cerebral gliomas when the tumor volume is derived from MET/PET images.
Source: Japanese Journal of Radiology - Category: Radiology Source Type: research
Conclusion: Our study results suggested that measurement of CBF from ASL possesses the potential for a noninvasive assessment of blood flow in intracranial tumors as an alternate to DSC MRI, in those patients requiring multiple follow-up imaging and in patients with impaired renal functions.
Source: Neurology India - Category: Neurology Authors: Source Type: research
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