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International Journal of Stroke :... Oct 2023Fatigue is a common and disabling symptom following stroke, but its underlying mechanisms are unknown. Associations with a number of imaging features have been proposed. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Fatigue is a common and disabling symptom following stroke, but its underlying mechanisms are unknown. Associations with a number of imaging features have been proposed.
AIMS
We aimed to assess whether neuroimaging parameters could better inform our understanding of possible causes of post-stroke fatigue (PSF) through systematic review and meta-analysis.
METHODS
Using a predefined protocol registered with PROSPERO (ID: CRD42022303168), we searched EMBASE, MEDLINE, PubMed, and PsycInfo for studies assessing PSF and computerized tomography (CT), magnetic resonance (MR), positron emission tomography (PET) imaging, or diffusion tensor imaging (DTI). We extracted neuroimaging parameters and narratively analyzed study results to assess any association with PSF. Where there were 3+ similar studies, we carried out a meta-analysis using inverse-variance random-effects model to estimate the total association of each neuroimaging parameter on PSF. The risk of bias was assessed using the Newcastle and Ottawa Scale.
RESULTS
We identified 46 studies ( = 6543); in many studies, associations with fatigue were secondary or subanalyses (28.3%). Imaging parameters were assessed across eight variables: lesion lateralization, lesion location, lesion volume, brain atrophy, infarct number, cerebral microbleeds, white matter hyperintensities (WMHs), and network measures. Most variables showed no conclusive evidence for any association with fatigue. Meta-analysis, where possible, showed no association of the following with PSF; left lesion lateralization (OR: 0.88, 95% CI (0.64, 1. 22) ( 0.45)), infratentorial lesion location (OR: 1.83, 95% CI (0.63, 5.32) ( 0.27)), and WMH (OR: 1.21, 95% CI (0.84, 1.75) ( 0.29)). Many studies assessed lesion location with mixed findings; only one used voxel-symptom lesion-mapping (VSLM). Some small studies suggested an association between altered functional brain networks, namely frontal, fronto-striato-thalamic, and sensory processing networks, with PSF.
CONCLUSION
There was little evidence for the association between any neuroimaging parameters and PSF. Future studies should utilize advanced imaging techniques to fully understand the role of lesion location in PSF, while the role of altered brain networks in mediating PSF merits further research.
Topics: Humans; Brain; Diffusion Tensor Imaging; Fatigue; Magnetic Resonance Imaging; Neuroimaging; Stroke
PubMed: 37485902
DOI: 10.1177/17474930231192214 -
Pharmaceuticals (Basel, Switzerland) Nov 2023Several studies have examined the use of positron emission tomography (PET) using [Ga]Ga-radiolabeled fibroblast-activation protein inhibitors (FAPi) across multiple... (Review)
Review
Diagnostic Accuracy of [Ga]Ga Labeled Fibroblast-Activation Protein Inhibitors in Detecting Head and Neck Cancer Lesions Using Positron Emission Tomography: A Systematic Review and a Meta-Analysis.
Several studies have examined the use of positron emission tomography (PET) using [Ga]Ga-radiolabeled fibroblast-activation protein inhibitors (FAPi) across multiple subtypes of head and neck cancer (HNC). The purpose of the present study was to evaluate the diagnostic accuracy of a newly developed molecular imaging approach in the context of HNC through a comprehensive review and meta-analysis. A thorough literature review was conducted to identify scholarly articles about the diagnostic effectiveness of FAP-targeted PET imaging. The present study incorporates original publications assessing the efficacy of this innovative molecular imaging test in both newly diagnosed and previously treated HNC patients. This systematic review examined eleven investigations, of which nine were deemed suitable for inclusion in the subsequent meta-analysis. The quantitative synthesis yielded a pooled detection rate of 99% for primary HNC lesions. Additionally, on a per patient-based analysis, the pooled sensitivity and specificity for regional lymph node metastases were found to be 90% and 84%, respectively. The analysis revealed a statistical heterogeneity among the studies for the detection rate of primary HNC lesions. The quantitative findings presented in this study indicate a favorable diagnostic performance of FAP-targeted PET imaging in detecting primary HNC tumors. In contrast, discordant results concerning the diagnostic accuracy of lymph node metastases were found. However, further multicentric trials are required to validate the efficacy of FAP-targeted PET in this specific group of patients.
PubMed: 38139791
DOI: 10.3390/ph16121664 -
Cancers Sep 2023Neuroendocrine prostate cancer (NEPC) is a rare neoplasm, and the role of both conventional imaging (CI) and positron emission tomography/computed tomography (PET/CT)... (Review)
Review
BACKGROUND
Neuroendocrine prostate cancer (NEPC) is a rare neoplasm, and the role of both conventional imaging (CI) and positron emission tomography/computed tomography (PET/CT) for its assessment has not been clearly evaluated and demonstrated. The aim of this systematic review was to analyze the diagnostic performances of these imaging modalities in this setting.
METHODS
A wide literature search of the PubMed/MEDLINE, Scopus, and Web of Science databases was made to find relevant published articles about the role of CI and PET/CT for the evaluation of NEPC.
RESULTS
13 studies were included in the systematic review. PET/CT imaging with different radiopharmaceuticals has been evaluated in many studies (10) compared to CI (3 studies), which has only a limited role in NEPC. Focusing on PET/CT, a study used [F]FDG, labeled somatostatin analogs were used in 5 cases, a study used [Ga]Ga-FAPI-04, [Ga]Ga-PSMA-11 was evaluated in a single case, and two works used different tracers.
CONCLUSION
Published data on the role of PET/CT for the assessment of NEPC are limited. At present, it is still uncertain which tracer performs best, and although [F]FDG has been evaluated and seems to offer some advantages in availability and clinical staging, other tracers may be more useful to understand tumor biology or identify targets for subsequent radioligand therapy. Further research is therefore desirable. In contrast, data are still limited to draw a final conclusion on the role and the specific characteristics of CI in this rare form of neoplasm, and therefore, more studies are needed in this setting.
PubMed: 37686680
DOI: 10.3390/cancers15174404 -
Journal of Sport and Health Science Mar 2024One of the pathological hallmarks distinguishing Alzheimer's disease from other dementias is the accumulation of amyloid beta (Aβ). Higher physical activity is... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
One of the pathological hallmarks distinguishing Alzheimer's disease from other dementias is the accumulation of amyloid beta (Aβ). Higher physical activity is associated with decreased dementia risk, and one potential path could be through Aβ levels modulation. We aimed to explore the relationship between physical activity and Aβ in middle-aged and older adults.
METHODS
A systematic search of PubMed, Web of Science, PsycINFO, Cochrane Central Register of Controlled Trials, and SPORTDiscus was performed from inception to April 28, 2022. Studies were eligible if they included physical activity and Aβ data in adults aged 45 years or older. Multi-level meta-analyses of intervention and observational studies were performed to examine the role of physical activity in modulating Aβ levels.
RESULTS
In total, 37 articles were included (8 randomized controlled trials, 3 non-randomized controlled trials, 4 prospective longitudinal studies, and 22 cross-sectional studies). The overall effect size of physical activity interventions on changes in blood Aβ was medium (pooled standardized mean difference = -0.69, 95% confidence interval (95%CI): -1.41 to 0.03; I = 74.6%). However, these results were not statistically significant, and there were not enough studies to explore the effects of physical activity on cerebrospinal fluid (CSF) and brain Aβ. Data from observational studies were examined based on measurements of Aβ in the brain using positron emission tomography scans, CSF, and blood. Higher physical activity was positively associated with Aβ only in the CSF (Estimate r = 0.12; 95%CI: 0.05-0.18; I = 38.00%).
CONCLUSION
Physical activity might moderately reduce blood Aβ in middle-aged and older adults. However, results were only near statistical significance and might be interpreted with caution given the methodological limitations observed in some of the included studies. In observational studies, higher levels of physical activity were positively associated with Aβ only in CSF. Therefore, further research is needed to understand the modulating role of physical activity in the brain, CSF, and blood Aβ, as well as its implication for cognitive health.
Topics: Middle Aged; Humans; Aged; Amyloid beta-Peptides; Prospective Studies; Cross-Sectional Studies; Alzheimer Disease; Brain
PubMed: 37558161
DOI: 10.1016/j.jshs.2023.08.001 -
Obesity Reviews : An Official Journal... Nov 2023This systematic review collates studies of dietary or bariatric surgery interventions for obesity using positron emission tomography and single-photon emission computed... (Review)
Review
Effects of bariatric surgery and dietary interventions for obesity on brain neurotransmitter systems and metabolism: A systematic review of positron emission tomography (PET) and single-photon emission computed tomography (SPECT) studies.
This systematic review collates studies of dietary or bariatric surgery interventions for obesity using positron emission tomography and single-photon emission computed tomography. Of 604 publications identified, 22 met inclusion criteria. Twelve studies assessed bariatric surgery (seven gastric bypass, five gastric bypass/sleeve gastrectomy), and ten dietary interventions (six low-calorie diet, three very low-calorie diet, one prolonged fasting). Thirteen studies examined neurotransmitter systems (six used tracers for dopamine DRD2/3 receptors: two each for C-raclopride, F-fallypride, I-IBZM; one for dopamine transporter, I-FP-CIT; one used tracer for serotonin 5-HT receptor, F-altanserin; two used tracers for serotonin transporter, C-DASB or I-FP-CIT; two used tracer for μ-opioid receptor, C-carfentanil; one used tracer for noradrenaline transporter, C-MRB); seven studies assessed glucose uptake using F-fluorodeoxyglucose; four studies assessed regional cerebral blood flow using O-H O (one study also used arterial spin labeling); and two studies measured fatty acid uptake using F-FTHA and one using C-palmitate. The review summarizes findings and correlations with clinical outcomes, eating behavior, and mechanistic mediators. The small number of studies using each tracer and intervention, lack of dietary intervention control groups in any surgical studies, heterogeneity in time since intervention and degree of weight loss, and small sample sizes hindered the drawing of robust conclusions across studies.
Topics: Humans; Positron-Emission Tomography; Tomography, Emission-Computed, Single-Photon; Bariatric Surgery; Brain; Obesity; Neurotransmitter Agents
PubMed: 37699864
DOI: 10.1111/obr.13620 -
Neuroscience and Biobehavioral Reviews Apr 2024Conflicting evidence exists on the relationship between diabetes mellitus (DM) and Alzheimer's disease (AD) biomarkers. Therefore, we conducted a random-effects... (Meta-Analysis)
Meta-Analysis
Conflicting evidence exists on the relationship between diabetes mellitus (DM) and Alzheimer's disease (AD) biomarkers. Therefore, we conducted a random-effects meta-analysis to evaluate the correlation of glucose metabolism measures (glycated hemoglobin, fasting blood glucose, insulin resistance indices) and DM status with AD biomarkers of amyloid-β and tau measured by positron emission tomography or cerebrospinal fluid. We selected 37 studies from PubMed and Embase, including 11,694 individuals. More impaired glucose metabolism and DM status were associated with higher tau biomarkers (r=0.11[0.03-0.18], p=0.008; I2=68%), but were not associated with amyloid-β biomarkers (r=-0.06[-0.13-0.01], p=0.08; I=81%). Meta-regression revealed that glucose metabolism and DM were specifically associated with tau biomarkers in population settings (p=0.001). Furthermore, more impaired glucose metabolism and DM status were associated with lower amyloid-β biomarkers in memory clinic settings (p=0.004), and in studies with a higher prevalence of dementia (p<0.001) or lower cognitive scores (p=0.04). These findings indicate that DM is associated with biomarkers of tau but not with amyloid-β. This knowledge is valuable for improving dementia and DM diagnostics and treatment.
Topics: Humans; Alzheimer Disease; Amyloid beta-Peptides; Biomarkers; Cognitive Dysfunction; Diabetes Mellitus; Glucose; Peptide Fragments; Positron-Emission Tomography; tau Proteins
PubMed: 38423195
DOI: 10.1016/j.neubiorev.2024.105604 -
Seminars in Nuclear Medicine Sep 2023Fibroblast activation protein inhibitor (FAPI) is a promising tracer in oncologic positron emission tomography/computed tomography (PET/CT). Numerous studies have... (Review)
Review
Fibroblast activation protein inhibitor (FAPI) is a promising tracer in oncologic positron emission tomography/computed tomography (PET/CT). Numerous studies have demonstrated the superior sensitivity of FAPI PET/CT over fluorodeoxyglucose (FDG) PET/CT in several types of cancer. However, the cancer specificity of FAPI uptake remains understudied, and several cases of false-positive FAPI PET/CT findings have been reported. A systematic search of PubMed, Embase, and Web of Science was conducted for studies published prior to April 2022 reporting nonmalignant FAPI PET/CT findings. We included original peer-reviewed articles of studies in humans using FAPI tracers radiolabeled with Ga or F that were published in English. Papers without original data and studies with insufficient information were excluded. Nonmalignant findings were presented on a per-lesion basis and grouped according to the type of organ or tissue involved. The search identified a total of 1.178 papers, of which 108 studies were eligible. Eighty studies were case reports (74%), and the remaining 28 were cohort studies (26%). A total of 2.372 FAPI-avid nonmalignant findings were reported, with the most frequent being uptake in the arteries, e.g., related to plaques (n = 1178, 49%). FAPI uptake was also frequently related to degenerative and traumatic bone and joint lesions (n = 147, 6%) or arthritis (n = 92, 4%). For organs, diffuse or focal uptake was often seen in cases of inflammation, infection, fibrosis, and IgG4-related disease (n = 157, 7%). FAPI-avid inflammatory/reactive lymph nodes (n = 121, 5%) and tuberculosis lesions (n = 51, 2%) have been reported and could prove to be potential pitfalls in cancer staging. Periodontitis (n = 76, 3%), hemorrhoids (n = 47, 2%), and scarring/wound healing (n = 35, 2%) also presented as focal uptake on FAPI PET/CT. The present review provides an overview of the reported FAPI-avid nonmalignant PET/CT findings to date. A large number of benign clinical entities may show FAPI uptake and should be kept in mind when interpreting FAPI PET/CT findings in patients with cancer.
Topics: Humans; Biological Transport; Fluorodeoxyglucose F18; Gallium Radioisotopes; Inflammation; Positron Emission Tomography Computed Tomography
PubMed: 36813670
DOI: 10.1053/j.semnuclmed.2023.02.001 -
Journal of Psychopharmacology (Oxford,... Nov 2023Major depressive disorder (MDD) is a leading cause of global disability. Several lines of evidence implicate the dopamine system in its pathophysiology. However, the... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Major depressive disorder (MDD) is a leading cause of global disability. Several lines of evidence implicate the dopamine system in its pathophysiology. However, the magnitude and consistency of the findings are unknown. We address this by systematically reviewing in vivo imaging evidence for dopamine measures in MDD and meta-analysing these where there are sufficient studies.
METHODS
Studies investigating the dopaminergic system using positron emission tomography or single photon emission computed tomography in MDD and a control group were included. Demographic, clinical and imaging measures were extracted from each study, and meta-analyses and sensitivity analyses were conducted.
RESULTS
We identified 43 studies including 662 patients and 801 controls. Meta-analysis of 38 studies showed no difference in mean or mean variability of striatal D receptor availability ( = 0.06, = 0.620), or combined dopamine synthesis and release capacity ( = 0.19, = 0.309). Dopamine transporter (DAT) availability was lower in the MDD group in studies using DAT selective tracers ( = -0.56, = 0.006), but not when tracers with an affinity for serotonin transporters were included ( = -0.21, = 0.420). Subgroup analysis showed greater dopamine release ( = 0.49, = 0.030), but no difference in dopamine synthesis capacity ( = -0.21, = 0.434) in the MDD group. Striatal D receptor availability was lower in patients with MDD in two studies.
CONCLUSIONS
The meta-analysis indicates striatal DAT availability is lower, but D receptor availability is not altered in people with MDD compared to healthy controls. There may be greater dopamine release and lower striatal D receptors in MDD, although further studies are warranted. We discuss factors associated with these findings, discrepancies with preclinical literature and implications for future research.
Topics: Humans; Dopamine; Depressive Disorder, Major; Tomography, Emission-Computed, Single-Photon; Positron-Emission Tomography; Receptors, Dopamine D2; Dopamine Plasma Membrane Transport Proteins
PubMed: 37811803
DOI: 10.1177/02698811231200881 -
Autoimmunity Reviews Feb 2024Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating condition characterized by an elusive etiology and pathophysiology. This study aims to... (Meta-Analysis)
Meta-Analysis
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating condition characterized by an elusive etiology and pathophysiology. This study aims to evaluate the pathological role of neuroinflammation in ME/CFS by conducting an exhaustive analysis of 65 observational studies. Four neuroimaging techniques, including magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), electroencephalography (EEG), and positron emission tomography (PET), were employed to comparatively assess brain regional structure, metabolite profiles, electrical activity, and glial activity in 1529 ME/CFS patients (277 males, 1252 females) and 1715 controls (469 males, 1246 females). Clinical characteristics, including sex, age, and fatigue severity, were consistent with established epidemiological patterns. Regional alterations were most frequently identified in the cerebral cortex, with a notable focus on the frontal cortex. However, our meta-analysis data revealed a significant hypoactivity in the insular and thalamic regions, contrary to observed frequencies. These abnormalities, occurring in pivotal network hubs bridging reason and emotion, disrupt connections with the limbic system, contributing to the hallmark symptoms of ME/CFS. Furthermore, we discuss the regions where neuroinflammatory features are frequently observed and address critical neuroimaging limitations, including issues related to inter-rater reliability. This systematic review serves as a valuable guide for defining regions of interest (ROI) in future neuroimaging investigations of ME/CFS.
Topics: Female; Humans; Male; Brain; Electroencephalography; Fatigue Syndrome, Chronic; Magnetic Resonance Imaging; Neuroimaging; Neuroinflammatory Diseases; Positron-Emission Tomography
PubMed: 38016575
DOI: 10.1016/j.autrev.2023.103484 -
Cancer Medicine Aug 2023Positron emission tomography (PET) images of head and neck squamous cell carcinoma (HNSCC) patients can assess the functional and biochemical processes at cellular... (Meta-Analysis)
Meta-Analysis Review
A systematic review and meta-analysis of predictive and prognostic models for outcome prediction using positron emission tomography radiomics in head and neck squamous cell carcinoma patients.
BACKGROUND
Positron emission tomography (PET) images of head and neck squamous cell carcinoma (HNSCC) patients can assess the functional and biochemical processes at cellular levels. Therefore, PET radiomics-based prediction and prognostic models have the potentials to understand tumour heterogeneity and assist clinicians with diagnosis, prognosis and management of the disease. We conducted a systematic review of published modelling information to evaluate the usefulness of PET radiomics in the prediction and prognosis of HNSCC patients.
METHODS
We searched bibliographic databases (MEDLINE, Embase, Web of Science) from 2010 to 2021 and considered 31 studies with pre-defined inclusion criteria. We followed the CHARMS checklist for data extraction and performed quality assessment using the PROBAST tool. We conducted a meta-analysis to estimate the accuracy of the prediction and prognostic models using the diagnostic odds ratio (DOR) and average C-statistic, respectively.
RESULTS
Manual segmentation method followed by 40% of the maximum standardised uptake value (SUV ) thresholding is a commonly used approach. The area under the receiver operating curves of externally validated prediction models ranged between 0.60-0.87, 0.65-0.86 and 0.62-0.75 for overall survival, distant metastasis and recurrence, respectively. Most studies highlighted an overall high risk of bias (outcome definition, statistical methodologies and external validation of models) and high unclear concern in terms of applicability. The meta-analysis showed the estimated pooled DOR of 6.75 (95% CI: 4.45, 10.23) for prediction models and the C-statistic of 0.71 (95% CI: 0.67, 0.74) for prognostic models.
CONCLUSIONS
Both prediction and prognostic models using clinical variables and PET radiomics demonstrated reliable accuracy for detecting adverse outcomes in HNSCC, suggesting the prospect of PET radiomics in clinical settings for diagnosis, prognosis and management of HNSCC patients. Future studies of prediction and prognostic models should emphasise the quality of reporting, external model validation, generalisability to real clinical scenarios and enhanced reproducibility of results.
Topics: Humans; Squamous Cell Carcinoma of Head and Neck; Prognosis; Reproducibility of Results; Positron-Emission Tomography; Head and Neck Neoplasms; Fluorodeoxyglucose F18
PubMed: 37353996
DOI: 10.1002/cam4.6278