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Journal of Visualized Experiments : JoVE Oct 2023Stem cell and chimeric antigen receptor (CAR) T-cell therapies are emerging as promising therapeutics for organ regeneration and as immunotherapy for various cancers....
Stem cell and chimeric antigen receptor (CAR) T-cell therapies are emerging as promising therapeutics for organ regeneration and as immunotherapy for various cancers. Despite significant progress having been made in these areas, there is still more to be learned to better understand the pharmacokinetics and pharmacodynamics of the administered therapeutic cells in the living system. For noninvasive, in vivo tracking of cells with positron emission tomography (PET), a novel [Zr]Zr-p-isothiocyanatobenzyl-desferrioxamine ([Zr]Zr-DBN)-mediated cell radiolabeling method has been developed utilizing Zr (t1/2 78.4 h). The present protocol describes a [Zr]Zr-DBN-mediated, ready-to-use, radiolabeling synthon for direct radiolabeling of variety of cells, including mesenchymal stem cells, lineage-guided cardiopoietic stem cells, liver regenerating hepatocytes, white blood cells, melanoma cells, and dendritic cells. The developed methodology enables noninvasive PET imaging of cell trafficking for up to 7 days post-administration without affecting the nature or the function of the radiolabeled cells. Additionally, this protocol describes a stepwise method for the radiosynthesis of [Zr]Zr-DBN, biocompatible formulation of [Zr]Zr-DBN, preparation of cells for radiolabeling, and finally the radiolabeling of cells with [Zr]Zr-DBN, including all the intricate details needed for the successful radiolabeling of cells.
Topics: Humans; Radioisotopes; Positron-Emission Tomography; Neoplasms; Immunotherapy; Immunotherapy, Adoptive; Zirconium; Cell Line, Tumor
PubMed: 37955388
DOI: 10.3791/64117 -
Journal of Nuclear Cardiology :... Aug 2023Coronary flow reserve (CFR) with positron emission tomography/computed tomography (PET/CT) has an important role in the diagnosis of coronary microvascular disease... (Review)
Review
Coronary flow reserve (CFR) with positron emission tomography/computed tomography (PET/CT) has an important role in the diagnosis of coronary microvascular disease (CMD), aids risk stratification and may be useful in monitoring therapy. CMD contributes to symptoms and a worse prognosis in patients with coronary artery disease (CAD), nonischemic cardiomyopathies, and heart failure. CFR measurements may improve our understanding of the role of CMD in symptoms and prognosis in CAD and other cardiovascular diseases. The clinical presentation of CAD has changed. The prevalence of nonobstructive CAD has increased to about 50% of patients with angina undergoing angiography. Ischemia with nonobstructive arteries (INOCA) is recognized as an important cause of symptoms and has an adverse prognosis. Patients with INOCA may have ischemia due to CMD, epicardial vasospasm or diffuse nonobstructive CAD. Reduced CFR in patients with INOCA identifies a high-risk group that may benefit from management strategies specific for CMD. Although measurement of CFR by PET/CT has excellent accuracy and repeatability, use is limited by cost and availability. CFR measurement with single-photon emission tomography (SPECT) is feasible, validated, and would increase availability and use of CFR. Patients with CMD can be identified by reduced CFR and selected for specific therapies.
Topics: Humans; Positron Emission Tomography Computed Tomography; Coronary Angiography; Positron-Emission Tomography; Coronary Artery Disease; Risk Assessment; Cardiology; Coronary Circulation
PubMed: 35851643
DOI: 10.1007/s12350-022-03051-z -
Journal of Nuclear Cardiology :... Oct 2023
Topics: Humans; Tomography, X-Ray Computed; Heart; Positron-Emission Tomography
PubMed: 37670174
DOI: 10.1007/s12350-023-03355-8 -
Annals of the Academy of Medicine,... Nov 2023This study aimed to evaluate the clinical utility of positron emission tomography/magnetic resonance imaging (PET/MRI), especially in comparison with PET/computed... (Comparative Study)
Comparative Study
INTRODUCTION
This study aimed to evaluate the clinical utility of positron emission tomography/magnetic resonance imaging (PET/MRI), especially in comparison with PET/computed tomography (CT), which has been widely used in clinical practice in multiple myeloma.
METHOD
F-18 fluorodeoxyglucose PET/MRI and PET/ CT studies were done at baseline and when at least a partial response to treatment was achieved. These were done for newly-diagnosed myeloma patients who have not had more than 1 cycle of anti-myeloma treatment, or for relapsed and/or refractory myeloma patients before the start of next line of therapy.
RESULTS
PET/MRI correlated significantly with PET/CT, in terms of number of lesions detected, standardised uptake value (SUVmean and SUVmax, both at baseline and post-treatment. PET/MRI and PET/CT correlated with survival at baseline, but not post-treatment.
CONCLUSION
In this study, PET/MRI was more sensitive in detecting early disease and disease resolution post-treatment, compared with PET/CT. However, PET/MRI was less sensitive in detecting lesions in the ribs, clavicle and skull.
Topics: Multiple Myeloma; Humans; Magnetic Resonance Imaging; Positron Emission Tomography Computed Tomography; Fluorodeoxyglucose F18; Male; Female; Middle Aged; Aged; Positron-Emission Tomography; Multimodal Imaging; Radiopharmaceuticals; Adult; Sensitivity and Specificity; Aged, 80 and over
PubMed: 38920148
DOI: 10.47102/annals-acadmedsg.2022414 -
Journal of the American Veterinary... Nov 2023To assess the value of 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) for imaging the tarsus and proximal metatarsus and compare it with CT and...
OBJECTIVE
To assess the value of 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) for imaging the tarsus and proximal metatarsus and compare it with CT and lameness evaluation.
ANIMALS
25 horses with lameness localized to the tarsal and proximal metatarsal regions that underwent 18F-NaF PET/CT between 2016 and 2021.
METHODS
18F-NaF PET and CT images were retrospectively independently evaluated by 3 observers. Standardized uptake values (SUV) were used to characterize 18F-NaF uptake. Correlation between PET and CT findings with subjective and objective maximum (Max-D) and minimum pelvic height lameness data was estimated.
RESULTS
The inter-observer Kappa-weighted value (κ) was higher for PET (κ = 0.66) than CT (κ = 0.6). CT and PET scores were fairly correlated (R = 0.49; P < 0.05). PET SUVratio (SUV of the main lesion/SUV talus) had the highest correlation with Max-D (R = 0.71; P < .05). PET and CT scores for the plantar region were significantly higher in Quarter Horses (P < .05) and showed consistently higher correlation with objective lameness data (CT plantar grade - Max-D [R = 0.6; P < .05], PET plantar grade - Max-D [R = 0.47; P = .04]) than other regions of the distal tarsal joints. Three Warmbloods presented marked uptake at the medial cochlea of the distal tibia.
CLINICAL RELEVANCE
PET had a moderate correlation with CT for assessment of tarsal lesions. The degree of PET uptake can help differentiate active versus inactive lesions. Specific location of the uptake is important in determining clinical relevance.
Topics: Animals; Horses; Sodium Fluoride; Positron Emission Tomography Computed Tomography; Lameness, Animal; Retrospective Studies; Positron-Emission Tomography; Tomography, X-Ray Computed; Horse Diseases
PubMed: 37562781
DOI: 10.2460/javma.23.03.0164 -
European Journal of Nuclear Medicine... Jul 2024Non-invasive detection of pathological changes in thoracic aortic disease remains an unmet clinical need particularly for patients with congenital heart disease....
INTRODUCTION
Non-invasive detection of pathological changes in thoracic aortic disease remains an unmet clinical need particularly for patients with congenital heart disease. Positron emission tomography combined with magnetic resonance imaging (PET-MRI) could provide a valuable low-radiation method of aortic surveillance in high-risk groups. Quantification of aortic microcalcification activity using sodium [F]fluoride holds promise in the assessment of thoracic aortopathies. We sought to evaluate aortic sodium [F]fluoride uptake in PET-MRI using three methods of attenuation correction compared to positron emission tomography computed tomography (PET-CT) in patients with bicuspid aortic valve, METHODS: Thirty asymptomatic patients under surveillance for bicuspid aortic valve disease underwent sodium [F]fluoride PET-CT and PET-MRI of the ascending thoracic aorta during a single visit. PET-MRI data were reconstructed using three iterations of attenuation correction (Dixon, radial gradient recalled echo with two [RadialVIBE-2] or four [RadialVIBE-4] tissue segmentation). Images were qualitatively and quantitatively analysed for aortic sodium [F]fluoride uptake on PET-CT and PET-MRI.
RESULTS
Aortic sodium [F]fluoride uptake on PET-MRI was visually comparable with PET-CT using each reconstruction and total aortic standardised uptake values on PET-CT strongly correlated with each PET-MRI attenuation correction method (Dixon R = 0.70; RadialVIBE-2 R = 0.63; RadialVIBE-4 R = 0.64; p < 0.001 for all). Breathing related artefact between soft tissue and lung were detected using Dixon and RadialVIBE-4 but not RadialVIBE-2 reconstructions, with the presence of this artefact adjacent to the atria leading to variations in blood pool activity estimates. Consequently, quantitative agreements between radiotracer activity on PET-CT and PET-MRI were most consistent with RadialVIBE-2.
CONCLUSION
Ascending aortic microcalcification analysis in PET-MRI is feasible with comparable findings to PET-CT. RadialVIBE-2 tissue attenuation correction correlates best with the reference standard of PET-CT and is less susceptible to artefact. There remain challenges in segmenting tissue types in PET-MRI reconstructions, and improved attenuation correction methods are required.
Topics: Humans; Male; Female; Magnetic Resonance Imaging; Middle Aged; Multimodal Imaging; Aorta, Thoracic; Adult; Calcinosis; Positron-Emission Tomography; Aged; Aortic Valve; Image Processing, Computer-Assisted; Positron Emission Tomography Computed Tomography
PubMed: 38456972
DOI: 10.1007/s00259-024-06670-5 -
Nature Nanotechnology May 2024Positron emission particle tracking (PEPT) enables 3D localization and tracking of single positron-emitting radiolabelled particles with high spatiotemporal resolution....
Positron emission particle tracking (PEPT) enables 3D localization and tracking of single positron-emitting radiolabelled particles with high spatiotemporal resolution. The translation of PEPT to the biomedical imaging field has been limited due to the lack of methods to radiolabel biocompatible particles with sufficient specific activity and protocols to isolate a single particle in the sub-micrometre size range, below the threshold for capillary embolization. Here we report two key developments: the synthesis and Ga-radiolabelling of homogeneous silica particles of 950 nm diameter with unprecedented specific activities (2.1 ± 1.4 kBq per particle), and the isolation and manipulation of a single particle. We have combined these developments to perform in vivo PEPT and dynamic positron emission tomography (PET) imaging of a single radiolabelled sub-micrometre size particle using a pre-clinical positron emission tomography/computed tomography scanner. This work opens possibilities for quantitative assessment of haemodynamics in vivo in real time, at the whole-body level using minimal amounts of injected radioactive dose and material.
Topics: Animals; Positron-Emission Tomography; Gallium Radioisotopes; Mice; Silicon Dioxide; Particle Size; Nanoparticles; Positron Emission Tomography Computed Tomography
PubMed: 38242986
DOI: 10.1038/s41565-023-01589-8 -
Clinical Cancer Research : An Official... Sep 2023In a recent study, the authors developed a nectin-4-targeting bicyclic peptide-based radiotracer, 68Ga-N188, for PET imaging of advanced urothelial cancer. Preclinical...
In a recent study, the authors developed a nectin-4-targeting bicyclic peptide-based radiotracer, 68Ga-N188, for PET imaging of advanced urothelial cancer. Preclinical investigation and first-in-human study in 14 patients demonstrated excellent specificity and sensitivity of 68Ga-N188 in detecting metastases. These promising results support 68Ga-N188 as a companion diagnostic for future personalized cancer therapy. See related article by Duan et al., p. 3395.
Topics: Humans; Positron Emission Tomography Computed Tomography; Nectins; Carcinoma, Transitional Cell; Precision Medicine; Urinary Bladder Neoplasms; Positron-Emission Tomography; Cell Adhesion Molecules
PubMed: 37417960
DOI: 10.1158/1078-0432.CCR-23-1243 -
Clinical Radiology Sep 2023To investigate the opinions of clinician referrers on the presence and type of management advice in reports of positron-emission tomography (PET)-computed tomography... (Review)
Review
AIM
To investigate the opinions of clinician referrers on the presence and type of management advice in reports of positron-emission tomography (PET)-computed tomography (CT) examinations.
MATERIALS AND METHODS
Eighteen clinicians were interviewed using a structured questionnaire about their opinions on further management advice in PET-CT reports.
RESULTS
Opinions varied amongst clinicians, but some themes predominated: (1) advice on further imaging tests and areas outside the referrer's area of expertise are more welcome than other types of advice; (2) a differential diagnosis or clinical significance is of greater value than specific management advice; (3) some referrers do not want any further advice.
CONCLUSION
Before advising on further management, reporters should consider clinicians' opinions regarding this. Seeking the opinion of clinicians in other hospitals may be necessary. A review of the Royal College of Radiologists Actionable Reports standard to ensure it is more in line with the opinions of clinicians may be useful.
Topics: Humans; Positron Emission Tomography Computed Tomography; Surveys and Questionnaires; Positron-Emission Tomography
PubMed: 37349201
DOI: 10.1016/j.crad.2023.05.015 -
Radiology Aug 2023
Topics: Humans; Fluorodeoxyglucose F18; Positron Emission Tomography Computed Tomography; Lung Neoplasms; Positron-Emission Tomography; Gallium Radioisotopes; Quinolines
PubMed: 37552076
DOI: 10.1148/radiol.231768