Search results for "PET imaging"
showing 10 items of 25 documents
Phase 0/1 of Positron Emission Tomography (PET) imaging agent [18F]-ODS2004436 as a marker of EGFR mutation in patients with non-small cell lung canc…
2018
e24184Background: Multiple EGFR tyrosine kinase inhibitors (TKIs) are approved for treatment of NSCLC harboring EGFR activating mutations or secondary TKIs resistant mutation. We evaluate a new PET...
Improved radiosynthesis and preliminary in vivo evaluation of the 11C-labeled tetrazine [11C]AE-1 for pretargeted PET imaging
2019
Pretargeted nuclear imaging based on the ligation between tetrazines and nano-sized targeting agents functionalized with trans-cyclooctene (TCO) has recently been shown to improve both imaging contrast and dosimetry in nuclear imaging of nanomedicines. Herein, we describe the improved radiosynthesis of a 11 C-labeled tetrazine ([ 11 C]AE-1) and its preliminary evaluation in both mice and pigs. Pretargeted imaging in mice was carried out using both a new TCO-functionalized polyglutamic acid and a previously reported TCO-functionalized bisphosphonate system as targeting agents. Unfortunately, pretargeted imaging was not successful using these targeting agents in pair with [ 11 C]AE-1. Howeve…
18F-Florbetaben PET/CT to Assess Alzheimer's Disease: A new Analysis Method for Regional Amyloid Quantification.
2019
Background and purpose While AD can be definitively confirmed by postmortem histopathologic examination, in vivo imaging may improve the clinician's ability to identify AD at the earliest stage. The aim of the study was to test the performance of amyloid PET using new processing imaging algorithm for more precise diagnosis of AD. Methods Amyloid PET results using a new processing imaging algorithm (MRI-Less and AAL Atlas) were correlated with clinical, cognitive status, CSF analysis, and other imaging. The regional SUVR using the white matter of cerebellum as reference region and scores from clinical and cognitive tests were used to create ROC curves. Leave-one-out cross-validation was carr…
A smart and operator independent system to delineate tumours in Positron Emission Tomography scans
2018
Abstract Positron Emission Tomography (PET) imaging has an enormous potential to improve radiation therapy treatment planning offering complementary functional information with respect to other anatomical imaging approaches. The aim of this study is to develop an operator independent, reliable, and clinically feasible system for biological tumour volume delineation from PET images. Under this design hypothesis, we combine several known approaches in an original way to deploy a system with a high level of automation. The proposed system automatically identifies the optimal region of interest around the tumour and performs a slice-by-slice marching local active contour segmentation. It automa…
Molecular imaging of gastroenteropancreatic neuroendocrine tumors.
2010
Somatostatin-receptor scintigraphy has become an obligatory molecular imaging method in the management of patients with neuroendocrine tumors when metastatic disease is suspected. Using positron emission tomography and new somatostatin analogues, sensitivity of somatostatin receptor imaging has further increased. With a combination of morphologic imaging methods, such as hybrid imaging by PET/CT, this method represents the method of choice in many centers and efforts are under way to translate somatostatin receptor imaging onto a cellular level by endoscopic confocal microscopy. Other clinically relevant functional pathways in neuroendocrine tumors that are accessible by PET imaging are glu…
A fully automatic method for biological target volume segmentation of brain metastases
2016
Leksell Gamma Knife is a mini-invasive technique to obtain a complete destruction of cerebral lesions delivering a single high dose radiation beam. Positron Emission Tomography (PET) imaging is increasingly utilized for radiation treatment planning. Nevertheless, lesion volume delineation in PET datasets is challenging because of the low spatial resolution and high noise level of PET images. Nowadays, the biological target volume (BTV) is manually contoured on PET studies. This procedure is time expensive and operator-dependent. In this article, a fully automatic algorithm for the BTV delineation based on random walks (RW) on graphs is proposed. The results are compared with the outcomes of…
Comparison of different phosphorus-containing ligands complexing 68Ga for PET-imaging of bone metabolism
2010
Abstract 99mTc-phosphonate structures are well established tracers for bone tumour imaging. Our objective was to investigate different 68Ga-labelled phosphonate ligands concerning labelling kinetics, binding to hydroxyapatite and bone imaging using μ-PET. Seven macrocyclic phosphorus-containing ligands and EDTMP were labelled in nanomolar scale with n.c.a. 68Ga in Na-HEPES buffer at pH∼4. Except for DOTP, all ligands were labelled with >92% yield. Binding of the 68Ga-ligand complexes on hydroxyapatite was analysed to evaluate the effect of the number of the phosphorus acid groups on adsorption parameters. Adsorption of 68Ga-EDTMP and 68Ga-DOTP was >83%. For the 68Ga-NOTA-phosphonates …
An enhanced random walk algorithm for delineation of head and neck cancers in PET studies
2017
An algorithm for delineating complex head and neck cancers in positron emission tomography (PET) images is presented in this article. An enhanced random walk (RW) algorithm with automatic seed detection is proposed and used to make the segmentation process feasible in the event of inhomogeneous lesions with bifurcations. In addition, an adaptive probability threshold and a k-means based clustering technique have been integrated in the proposed enhanced RW algorithm. The new threshold is capable of following the intensity changes between adjacent slices along the whole cancer volume, leading to an operator-independent algorithm. Validation experiments were first conducted on phantom studies:…
PET Chemistry: Radiopharmaceuticals
2021
Although many radiolabelled compounds for PET imaging have been developed so far, only a few have reached the status of a clinically established and routinely used PET radiopharmaceutical. At the early stage of development, a reasonable medical indication is obviously fundamental for a PET radiopharmaceutical to be further considered as clinically relevant. However, besides a favourable in vivo behaviour and appropriate imaging characteristics, certain criteria have to be fulfilled, such as a fast, straightforward and reliable radiosynthesis; an assured stability of the label as well as of the compound itself and a good availability of a suitable precursor. In particular, the ease and relia…
Radiosynthesis of 3-indolyl[1-11C]acetic acid for phyto-PET-imaging: An improved production procedure and formulation method
2014
Abstract An improved production procedure and formulation method for the carbon-11 radiolabeled phytohormone, 3-indolyl-[l- 11 C]acetic acid ([ 11 C]IAA), was developed by modifying selected original reaction parameters. This updated procedure both doubled the yield (from 25.9±6.7% ( n =12) to 61.0±0.3% ( n =10)) and increased the concentration (0.2–0.4 GBq/0.15–0.3 mL), enabling us to provide the radiotracer [ 11 C]IAA suitable for in vivo phyto-PET-imaging studies. The specific activity was improved by more than a factor of three (26.7±5.6 GBq/µmol to 82.5±36.1 GBq/µmol). The total synthesis time for both production and formulation was 81.8±3.0 min ( n =10). In addition, a streamlined sem…