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International Journal of Molecular... Apr 2022Positron emission tomography (PET) uses radioactive tracers and enables the functional imaging of several metabolic processes, blood flow measurements, regional chemical... (Review)
Review
Positron emission tomography (PET) uses radioactive tracers and enables the functional imaging of several metabolic processes, blood flow measurements, regional chemical composition, and/or chemical absorption. Depending on the targeted processes within the living organism, different tracers are used for various medical conditions, such as cancer, particular brain pathologies, cardiac events, and bone lesions, where the most commonly used tracers are radiolabeled with 18F (e.g., [F]-FDG and NA [F]). Oxygen-15 isotope is mostly involved in blood flow measurements, whereas a wide array of C-based compounds have also been developed for neuronal disorders according to the affected neuroreceptors, prostate cancer, and lung carcinomas. In contrast, the single-photon emission computed tomography (SPECT) technique uses gamma-emitting radioisotopes and can be used to diagnose strokes, seizures, bone illnesses, and infections by gauging the blood flow and radio distribution within tissues and organs. The radioisotopes typically used in SPECT imaging are iodine-123, technetium-99m, xenon-133, thallium-201, and indium-111. This systematic review article aims to clarify and disseminate the available scientific literature focused on PET/SPECT radiotracers and to provide an overview of the conducted research within the past decade, with an additional focus on the novel radiopharmaceuticals developed for medical imaging.
Topics: Fluorodeoxyglucose F18; Humans; Male; Positron-Emission Tomography; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed
PubMed: 35563414
DOI: 10.3390/ijms23095023 -
RMD Open Aug 2023To update the evidence on imaging for diagnosis, monitoring and outcome prediction in large vessel vasculitis (LVV) to inform the 2023 update of the European Alliance of... (Meta-Analysis)
Meta-Analysis
Imaging in diagnosis, monitoring and outcome prediction of large vessel vasculitis: a systematic literature review and meta-analysis informing the 2023 update of the EULAR recommendations.
OBJECTIVES
To update the evidence on imaging for diagnosis, monitoring and outcome prediction in large vessel vasculitis (LVV) to inform the 2023 update of the European Alliance of Associations for Rheumatology recommendations on imaging in LVV.
METHODS
Systematic literature review (SLR) (2017-2022) including prospective cohort and cross-sectional studies (>20 participants) on diagnostic, monitoring, outcome prediction and technical aspects of LVV imaging. Diagnostic accuracy data were meta-analysed in combination with data from an earlier (2017) SLR.
RESULTS
The update retrieved 38 studies, giving a total of 81 studies when combined with the 2017 SLR. For giant cell arteritis (GCA), and taking clinical diagnosis as a reference standard, low risk of bias (RoB) studies yielded pooled sensitivities and specificities (95% CI) of 88% (82% to 92%) and 96% (95% CI 86% to 99%) for ultrasound (n=8 studies), 81% (95% CI 71% to 89%) and 98% (95% CI 89% to 100%) for MRI (n=3) and 76% (95% CI 67% to 83%) and 95% (95% CI 71% to 99%) for fluorodeoxyglucose positron emission tomography (FDG-PET, n=4), respectively. Compared with studies assessing cranial arteries only, low RoB studies with ultrasound assessing both cranial and extracranial arteries revealed a higher sensitivity (93% (95% CI 88% to 96%) vs 80% (95% CI 71% to 87%)) with comparable specificity (94% (95% CI 83% to 98%) vs 97% (95% CI 71% to 100%)). No new studies on diagnostic imaging for Takayasu arteritis (TAK) were found. Some monitoring studies in GCA or TAK reported associations of imaging with clinical signs of inflammation. No evidence was found to determine whether imaging severity might predict worse clinical outcomes.
CONCLUSION
Ultrasound, MRI and FDG-PET revealed a good performance for the diagnosis of GCA. Cranial and extracranial vascular ultrasound had a higher pooled sensitivity with similar specificity compared with limited cranial ultrasound.
Topics: Humans; Cross-Sectional Studies; Fluorodeoxyglucose F18; Prospective Studies; Giant Cell Arteritis; Positron-Emission Tomography
PubMed: 37620113
DOI: 10.1136/rmdopen-2023-003379 -
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 -
Diseases of the Esophagus : Official... May 2023Radiomics can interpret radiological images with more detail and in less time compared to the human eye. Some challenges in managing esophageal cancer can be addressed... (Meta-Analysis)
Meta-Analysis
Performance of radiomics-based artificial intelligence systems in the diagnosis and prediction of treatment response and survival in esophageal cancer: a systematic review and meta-analysis of diagnostic accuracy.
Radiomics can interpret radiological images with more detail and in less time compared to the human eye. Some challenges in managing esophageal cancer can be addressed by incorporating radiomics into image interpretation, treatment planning, and predicting response and survival. This systematic review and meta-analysis provides a summary of the evidence of radiomics in esophageal cancer. The systematic review was carried out using Pubmed, MEDLINE, and Ovid EMBASE databases-articles describing radiomics in esophageal cancer were included. A meta-analysis was also performed; 50 studies were included. For the assessment of treatment response using 18F-FDG PET/computed tomography (CT) scans, seven studies (443 patients) were included in the meta-analysis. The pooled sensitivity and specificity were 86.5% (81.1-90.6) and 87.1% (78.0-92.8). For the assessment of treatment response using CT scans, five studies (625 patients) were included in the meta-analysis, with a pooled sensitivity and specificity of 86.7% (81.4-90.7) and 76.1% (69.9-81.4). The remaining 37 studies formed the qualitative review, discussing radiomics in diagnosis, radiotherapy planning, and survival prediction. This review explores the wide-ranging possibilities of radiomics in esophageal cancer management. The sensitivities of 18F-FDG PET/CT scans and CT scans are comparable, but 18F-FDG PET/CT scans have improved specificity for AI-based prediction of treatment response. Models integrating clinical and radiomic features facilitate diagnosis and survival prediction. More research is required into comparing models and conducting large-scale studies to build a robust evidence base.
Topics: Humans; Positron Emission Tomography Computed Tomography; Fluorodeoxyglucose F18; Artificial Intelligence; Radiomics; Esophageal Neoplasms
PubMed: 37236811
DOI: 10.1093/dote/doad034 -
Theranostics 2023Recent studies suggest that Ga-FAPI PET/CT demonstrated superiority over F-FDG PET/CT in the evaluation of various cancer types, especially in gastric cancer (GC). By... (Meta-Analysis)
Meta-Analysis
Recent studies suggest that Ga-FAPI PET/CT demonstrated superiority over F-FDG PET/CT in the evaluation of various cancer types, especially in gastric cancer (GC). By comprehensively reviewing and analysing the differences between Ga-FAPI and F-FDG in GC, some evidence is provided to foster the broader clinical application of FAPI PET imaging. In this review, studies published up to July 3, 2023, that employed radionuclide labelled FAPI as a diagnostic radiotracer for PET in GC were analysed. These studies were sourced from both the PubMed and Web of Science databases. Our statistical analysis involved a bivariate meta-analysis of the diagnostic data and a meta-analysis of the quantitative metrics. These were performed using R language. The meta-analysis included 14 studies, with 527 patients, of which 358 were diagnosed with GC. Overall, Ga-FAPI showed higher pooled sensitivity (0.84 [95% CI 0.67-0.94] 0.46 [95% CI 0.32-0.60]), specificity (0.91 [95% CI 0.76-0.98] 0.88 [95% CI 0.74-0.96]) and area under the curve (AUC) (0.92 [95% CI 0.77-0.98] 0.52 [95% CI 0.38-0.86]) than F-FDG. The evidence showed superior pooled sensitivities of Ga-FAPI PET over F-FDG for primary tumours, local recurrence, lymph node metastases, distant metastases, and peritoneal metastases. Furthermore, Ga-FAPI PET provided higher maximum standardized uptake value (SUVmax) and tumour-to-background ratios (TBR). For bone metastases, while Ga-FAPI PET demonstrated slightly lower patient-based pooled sensitivity (0.93 1.00), it significantly outperformed F-FDG in the lesion-based analysis (0.95 0.65). However, SUVmax (mean difference [MD] 1.79 [95% CI -3.87-7.45]) and TBR (MD 5.01 [95% CI -0.78-10.80]) of bone metastases showed no significant difference between Ga-FAPI PET/CT and F-FDG PET/CT. Compared with F-FDG, Ga-FAPI PET imaging showed improved diagnostic accuracy in the evaluation of GC. It can be effectively applied to the early diagnosis, initial staging, and detection of recurrence/metastases of GC. Ga-FAPI may have the potential of replacing F-FDG in GC in future applications.
Topics: Humans; Stomach Neoplasms; Positron Emission Tomography Computed Tomography; Fluorodeoxyglucose F18; Gallium Radioisotopes; Positron-Emission Tomography
PubMed: 37649615
DOI: 10.7150/thno.88335 -
International Journal of Molecular... Jun 2023Various papers have introduced the use of positron emission tomography (PET) with [Ga]Ga-radiolabeled fibroblast-activation protein inhibitor (FAPi) radiopharmaceuticals... (Meta-Analysis)
Meta-Analysis Review
Various papers have introduced the use of positron emission tomography (PET) with [Ga]Ga-radiolabeled fibroblast-activation protein inhibitor (FAPi) radiopharmaceuticals in different subtypes of gastric cancer (GC). Our aim was to assess the diagnostic performance of this novel molecular imaging technique in GC with a systematic review and meta-analysis. A straightforward literature search of papers concerning the diagnostic performance of FAP-targeted PET imaging was performed. Original articles evaluating this novel molecular imaging examination in both newly diagnosed GC patients and GC patients with disease relapse were included. The systematic review included nine original studies, and eight of them were also eligible for meta-analysis. The quantitative synthesis provided pooled detection rates of 95% and 97% for the assessment of primary tumor and distant metastases, respectively, and a pooled sensitivity and specificity of 74% and 89%, respectively, for regional lymph node metastases. Significant statistical heterogeneity among the included studies was found only in the analysis of the primary tumor detection rate (I = 64%). Conclusions: Beyond the limitations of this systematic review and meta-analysis (i.e., all the included studies were conducted in Asia, and using [F]FDG PET/CT as a comparator of the index test), the quantitative data provided demonstrate the promising diagnostic performance of FAP-targeted PET imaging in GC. Nevertheless, more prospective multicentric studies are needed to confirm the excellent performances of FAP-targeted PET in this cluster of patients.
Topics: Humans; Positron Emission Tomography Computed Tomography; Stomach Neoplasms; Prospective Studies; Neoplasm Recurrence, Local; Positron-Emission Tomography; Radiopharmaceuticals; Fluorodeoxyglucose F18; Gallium Radioisotopes
PubMed: 37373285
DOI: 10.3390/ijms241210136 -
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 -
Seminars in Nuclear Medicine Nov 2023F-FDG-PET/CT imaging has become a key tool to evaluate infectious and inflammatory diseases. However, application of F-FDG-PET/CT in patients in the intensive care unit... (Review)
Review
F-FDG-PET/CT imaging has become a key tool to evaluate infectious and inflammatory diseases. However, application of F-FDG-PET/CT in patients in the intensive care unit (ICU) is limited, which is remarkable since the development of critical illness is closely linked to infection and inflammation. This limited use is caused by perceived complexity and risk of planning and executing F-FDG-PET/CT in such patients. The aim of this systematic review was to investigate the feasibility of F-FDG-PET/CT in ICU patients with special emphasis on patient preparation, transport logistics and safety. Therefore, a systematic search was performed in PubMed, Embase, and Web of Science using the search terms: intensive care, critically ill, positron emission tomography and F-FDG or derivates. A total of 1183 articles were found of which 10 were included. Three studies evaluated the pathophysiology of acute respiratory distress syndrome, acute lung injury and acute chest syndrome. Three other studies applied F-FDG-PET/CT to increase understanding of pathophysiology after traumatic brain injury. The remaining four studies evaluated infection of unknown origin. These four studies showed a sensitivity and specificity between 85%-100% and 57%-88%, respectively. A remarkable low adverse event rate of 2% was found during the entire F-FDG-PET/CT procedure, including desaturation and hypotension. In all studies, a team consisting of an intensive care physician and nurse was present during transport to ensure continuation of necessary critical care. Full monitoring during transport was used in patients requiring mechanical ventilation or vasopressor support. None of the studies used specific patient preparation for ICU patients. However, one article described specific recommendations in their discussion. In conclusion, F-FDG-PET/CT has been shown to be feasible and safe in ICU patients, even when ventilated or requiring vasopressors. Specific recommendations regarding patient preparation, logistics and scanning are needed. Including F-FDG-PET/CT in routine workup of infection of unknown origin in ICU patients showed potential to identify source of infection and might improve outcome.
Topics: Humans; Fluorodeoxyglucose F18; Positron Emission Tomography Computed Tomography; Radiopharmaceuticals; Positron-Emission Tomography; Critical Care; Intensive Care Units; Sensitivity and Specificity
PubMed: 37258380
DOI: 10.1053/j.semnuclmed.2023.05.003 -
Lung Cancer (Amsterdam, Netherlands) Dec 2021The role of PET and integrated PET-CT in the diagnostic workup of suspected malignant pleural effusions is unknown. Earlier systematic reviews (published 2014 and 2015)... (Meta-Analysis)
Meta-Analysis Review
The role of PET and integrated PET-CT in the diagnostic workup of suspected malignant pleural effusions is unknown. Earlier systematic reviews (published 2014 and 2015) both included pleural pathology without effusion, and reached contradictory conclusions. Five studies have been published since the latest review. This systematic review and meta-analysis aims to summarise the evidence of PET and integrated PET-CT in predicting pleural malignancy in patients suspected of having malignant pleural effusions. A meta-analysis based on a systematic literature search in Cochrane Library, Medline, EMBASE and Clinicaltrials.gov was performed. Diagnostic studies evaluating the performance of PET or PET-CT in patients with suspected malignant pleural effusion, using pleural fluid cytology or histopathology as the reference test, and presenting sufficient data for constructing a 2x2 table were included. The quality of the studies was assessed by the Quality Assessment of Diagnostic Accuracy Studies-2 score. Subgroup analyses on image modality, interpretation method and known malignancy status pre index-test application were planned. Seven studies with low risk of bias were included. The pooled ability to separate benign from malignant effusions varied with image modality, interpretation method and known malignancy status pre index-test application. In studies using PET-CT, visual/qualitative image analysis was superior to semi-quantitative with positive (LR + ) and negative likelihood ratio (LR-) of 9.9 (4.5-15.3) respectively 0.1 (0.1-0.2). There was considerable heterogeneity among studies. In conclusion, visual/qualitative image analysis of integrated PET-CT seems to add relevant information in the work-up of suspected malignant pleural effusions with LR + and LR- close to rigorous pre-set cut-offs of > 10 and < 0.1. However, the quality of evidence was low due to inter-study heterogeneity, and inability to assess meta-bias. Clinical Trial Registration: The protocol was uploaded to the PROSPERO database (CRD42020213319) on the 13th of October 2020.
Topics: Fluorodeoxyglucose F18; Humans; Lung Neoplasms; Pleural Effusion; Pleural Effusion, Malignant; Pleural Neoplasms; Positron Emission Tomography Computed Tomography; Positron-Emission Tomography; Radiopharmaceuticals; Sensitivity and Specificity
PubMed: 34775214
DOI: 10.1016/j.lungcan.2021.10.018 -
Current Oncology (Toronto, Ont.) Oct 2022The present study aimed to assess the existing data about Primary Adrenal Lymphoma (PAL) evaluated with FDG PET and to describe a small monocentric series of cases. A... (Review)
Review
The present study aimed to assess the existing data about Primary Adrenal Lymphoma (PAL) evaluated with FDG PET and to describe a small monocentric series of cases. A systematic analysis (from 2010 to 2022) was made by using PubMed and Web of Science databases reporting data about the role of FDG PET/CT in patients with suspicious or known adrenal lymphoma. The quality of the papers was assessed by using QUADAS-2 criteria. Moreover, from a single institutional collection between 2010 and 2021, data from patients affected by adrenal lymphoma and undergoing contrast-enhanced compute tomography (ceCT)/magnetic resonance (MR) and FDG PET/CT or PET/MR were retrieved and singularly described. Seventy-eight papers were available from PubMed and 25 from Web of Science. Forty-seven (Nr. 47) Patients were studied, most of them in the initial staging of disease ( = 42; 90%). Only in one paper, the scan was made before and after therapy. The selected clinical cases were relative to the initial staging of disease, the restaging, and the evaluation of response to therapy. PET/CT and PET/MR always showed a high FDG uptake in the primary adrenal lesions and in metastatic sites. Moreover, PET metrics, such as maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV), were elevated in all primary adrenal lesions. In conclusions, FDG PET either coupled with CT or MRI can be useful in staging, restaging, and for the evaluation of treatment response in patients affected by PAL.
Topics: Humans; Fluorodeoxyglucose F18; Positron Emission Tomography Computed Tomography; Radiopharmaceuticals; Lymphoma; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy
PubMed: 36290900
DOI: 10.3390/curroncol29100623