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Reviews in Endocrine & Metabolic... Feb 2024In the last years growing evidences on the role of radiomics and machine learning (ML) applied to different nuclear medicine imaging modalities for the assessment of... (Review)
Review
BACKGROUND
In the last years growing evidences on the role of radiomics and machine learning (ML) applied to different nuclear medicine imaging modalities for the assessment of thyroid diseases are starting to emerge. The aim of this systematic review was therefore to analyze the diagnostic performances of these technologies in this setting.
METHODS
A wide literature search of the PubMed/MEDLINE, Scopus and Web of Science databases was made in order to find relevant published articles about the role of radiomics or ML on nuclear medicine imaging for the evaluation of different thyroid diseases.
RESULTS
Seventeen studies were included in the systematic review. Radiomics and ML were applied for assessment of thyroid incidentalomas at F-FDG PET, evaluation of cytologically indeterminate thyroid nodules, assessment of thyroid cancer and classification of thyroid diseases using nuclear medicine techniques.
CONCLUSION
Despite some intrinsic limitations of radiomics and ML may have affect the results of this review, these technologies seem to have a promising role in the assessment of thyroid diseases. Validation of preliminary findings in multicentric studies is needed to translate radiomics and ML approaches in the clinical setting.
Topics: Humans; Fluorodeoxyglucose F18; Machine Learning; Nuclear Medicine; Radiomics; Thyroid Neoplasms; Thyroid Nodule; Thyroid Diseases
PubMed: 37434097
DOI: 10.1007/s11154-023-09822-4 -
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 -
Annals of Nuclear Medicine Aug 2023To provide an overview of the current available data about FAPI PET in breast cancer patients, with a perspective point of view. A literature search for studies about...
To provide an overview of the current available data about FAPI PET in breast cancer patients, with a perspective point of view. A literature search for studies about FAPI PET in the last 5 years (from 2017 to January 2023) was carried out on MEDLINE databases, such as PubMed, EMBASE, Web of Science and Google Scholar using the following keywords: "PET" AND "FAPI" AND "Breast Cancer" AND "Fibroblast imaging". The Critical Appraisal Skills Program (CASP) checklist for diagnostic test studies was used for testing the quality of selected papers. 13 articles were selected, including 172 patients affected by breast cancer who underwent FAPI-based PET images. CASP checklist was used in 5/13 papers, demonstrating a general low quality. Different types of FAPI-based tracers were used. No difference in terms of FAPI uptake was reported based on the histopathological characteristics, such as immunohistochemistry and grading of breast cancer. FAPI demonstrated more lesions and yielded much higher tumor-to-background ratios than 2-[18F]FDG. Preliminary experiences with FAPI PET in breast cancer showed some advantages than the current available 2-[18F]FDG, although prospective trials are needed to further evaluate its diagnostic utility in clinical practice.
Topics: Female; Humans; Breast Neoplasms; Positron Emission Tomography Computed Tomography; Fluorodeoxyglucose F18
PubMed: 37341971
DOI: 10.1007/s12149-023-01852-x -
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 -
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 -
Psychological Medicine Aug 2023Impaired brain metabolism may be central to schizophrenia pathophysiology, but the magnitude and consistency of metabolic dysfunction is unknown. (Meta-Analysis)
Meta-Analysis
BACKGROUND
Impaired brain metabolism may be central to schizophrenia pathophysiology, but the magnitude and consistency of metabolic dysfunction is unknown.
METHODS
We searched MEDLINE, PsychINFO and EMBASE between 01/01/1980 and 13/05/2021 for studies comparing regional brain glucose metabolism using FDG-PET, in schizophrenia/first-episode psychosis controls. Effect sizes (Hedges ) were pooled using a random-effects model. Primary measures were regional absolute and relative CMRGlu in frontal, temporal, parietal and occipital lobes, basal ganglia and thalamus.
RESULTS
Thirty-six studies (1335 subjects) were included. Frontal absolute glucose metabolism (Hedge's = -0.74 ± 0.54, = 0.01; = 67%) and metabolism relative to whole brain ( = -0.44 ± 0.34, = 0.01; = 55%) were lower in schizophrenia controls with moderate heterogeneity. Absolute frontal metabolism was lower in chronic ( = -1.18 ± 0.73) first-episode patients ( = -0.09 ± 0.88) and controls. Medicated patients showed frontal hypometabolism relative to controls (-1.04 ± 0.26) while metabolism in drug-free patients did not differ significantly from controls. There were no differences in parietal, temporal or occipital lobe or thalamic metabolism in schizophrenia controls. Excluding outliers, absolute basal ganglia metabolism was lower in schizophrenia controls (-0.25 ± 0.24, = 0.049; = 5%). Studies identified reporting voxel-based morphometry measures of absolute FDG uptake (eight studies) were also analysed using signed differential mapping analysis, finding lower FDG uptake in the left anterior cingulate gyrus ( = -4.143; = 0.007) and the left inferior orbital frontal gyrus ( = -4.239; = 0.02) in schizophrenia.
CONCLUSIONS
We report evidence for hypometabolism with large effect sizes in the frontal cortex in schizophrenia without consistent evidence for alterations in other brain regions. Our findings support the hypothesis of hypofrontality in schizophrenia.
Topics: Humans; Glucose; Schizophrenia; Fluorodeoxyglucose F18; Brain; Positron-Emission Tomography
PubMed: 35730361
DOI: 10.1017/S003329172200174X