Fluorodeoxyglucose Positron Emission Tomography Research Articles

Frequency and Early Predictors of Cognitive Deterioration in Amyotrophic Lateral Sclerosis: A Longitudinal Population-Based Study.

The objective is to evaluate cognitive and behavioral progression and identify early predictors of these changes in a cohort of amyotrophic lateral sclerosis (ALS) patients. A total of 161 ALS patients were tested at diagnosis (T0), and 107 were re-tested after 1 year (T1) using cognitive/behavioral tests. All patients underwent whole-genome sequencing, and 46 patients (ALS-normal cognition [CN]) underwent [18F]Fluorodeoxyglucose positron emission tomography. Of the 161 patients, 107 were re-rested at T1; non-retested patients included 10 with frontotemporal dementia and 44 who were either non-testable or deceased. At T0, 67 patients (62.6%) were classified as ALS-CN, whereas 40 (38.4%) showed some degree of cognitive/behavioral impairment. Eighteen ALS-CN patients (26.9%) experienced cognitive decline at T1. Phenoconverters had lower baseline scores in letter fluency (Letter Fluency Test [FAS]) (p < 0.001), Edinburgh Cognitive and Behavioral ALS Screen (ECAS) verbal fluency score (p = 0.017). Both tests were independently predictive of phenoconversion in binary logistic regression models, with optimal cut-off scores of 28.75 and 14.2, with good sensitivity and specificity. Other predictors included older age, lower education, and ALS-related genetic variants. Phenoconverters were hypometabolic in the left temporal lobe. Thirteen (32.5%) of the 40 patients with cognitive impairment at T0 worsened by T1, with FAS (p = 0.02) and the ECAS verbal fluency score (p = 0.023) predicting further decline. Approximately 30% of ALS patients experienced cognitive/behavioral decline within the first year after diagnosis. FAS and ECAS verbal fluency were predictive of cognitive phenoconversion. Our findings highlight the importance of early detection of at-risk individuals and the need for longitudinal cognitive assessments to monitor disease progression. ANN NEUROL 2025.

Echocardiographic predictors of right ventricular involvement in cardiac sarcoidosis

Abstract Background Right ventricular (RV) involvement in cardiac sarcoidosis (CS) is associated with adverse cardiovascular outcomes. Echocardiography is recommended in the screening of sarcoidosis patients for cardiac involvement. Abnormal imaging should prompt onward performance of cardiac magnetic resonance (CMR) and 18fluorodeoxy glucose positron emission tomography (FDG-PET). Suspicion of RV involvement in the screening phase could prompt more expedient advanced imaging. Purpose This study aimed to determine how well RV-focused echocardiographic parameters could predict RV involvement of CS. We defined RV involvement by the presence of RV impairment (RVEF &amp;lt;50%) and/or RV late gadolinium enhancement (LGE) on CMR and/or RV FDG-uptake on FDG-PET. Methods Consecutive patients referred for evaluation of suspected CS were prospectively recruited. All those with evidence of extracardiac sarcoidosis were included. Detailed 2D and 3D echocardiography with RV strain, CMR and FDG-PET was performed in all patients within 3 months. CS was diagnosed in line with the 2014 Heart Rhythm Society criteria. RV/pulmonary artery (PA) coupling was defined as the tricuspid annular plane systolic excursion (TAPSE):pulmonary artery systolic pressure (PASP) ratio. RV 4-chamber strain included the RV free wall and septal longitudinal strain components. Results Among the 198 sarcoidosis patients enrolled, 97 (49%) were diagnosed with CS. The prevalence of pulmonary hypertension was 3%. RV involvement was present in 26 (13%) among which 14 had RV free wall or septal LGE, 17 had CMR RVEF &amp;lt;50% and 10 had RV FDG uptake. Six patients had both LGE and FDG uptake while 8 patients had both LGE and RVEF &amp;lt;50%. Compared to those without, patients with RV impairment had lower RV fractional area change (38% [IQR 28-46] vs 43% [39-48], p=0.005), RV free wall strain (-17.7 ± 4.2% vs -22.5 ± 5.5%, p&amp;lt;0.001), RV 4-chamber strain (-13.9 ± 3.4% vs -18.5 ± 4.5%, p&amp;lt;0.001), 3DE RVEF (44 ± 7.4% vs 50 ± 7.5%, p=0.019) and greater RV basal diameter (3.99 ± 0.60cm vs 3.63 ± 0.58cm, p=0.004). There was no significant difference in TAPSE (p=0.091), PASP (p=0.811), RV/PA coupling (p=0.271) and tissue doppler RV S’ (p=0.203) values between the two groups. RV 4-chamber strain (AUC: 0.797) had the best ability to predict RV involvement followed by RV free wall strain (AUC: 0.757) and 3DE RVEF (AUC: 0.730). The optimal cut-off for RV 4-chamber strain to predict RV involvement was -15.3% which had 74% sensitivity and 77% specificity. Conclusion In a prospective cohort, RV strain is a useful indicator of RV involvement among suspected CS patients and should be performed routinely in all screening studies of sarcoidosis patients.

P-2126. ‘SPECIFIC’ First-In-Human Clinical Trial of 68Ga-triacetylfusarinine (TAFC) Siderophore PET/CT for Detection of Invasive Aspergillosis

Abstract Background Invasive Aspergillus spp. infections (IAI) confer high morbidity and mortality in immunocompromised patients. Diagnosis often requires invasive and risky sampling. 18F-fluorodeoxyglucose positron emission tomography with computed tomography (FDG-PET/CT) is useful in diagnosis but is non-specific. Siderophores are pathogen-specific iron chelators which are a promising radiolabelling target for IAI diagnosis. Aspergillus fumigatus secretes 2 siderophores, fusarinine C and triacetylfusarinine (TAFC), which are upregulated during IAI. Gallium-68 (68Ga)-labelled TAFC is attractive due to its short half life, rapid renal clearance, and low radiation risk. Preclinical mouse studies demonstrate diagnostic potential of 68Ga-TAFC PET/CT with specific visualisation of A. fumigatus infection.Figure 1:68Ga-TAFC-PET/CT in a patient with leukemia and probable pulmonary A. fumigatus IAI. Specific infective uptake of known pulmonary lesions at around blood pool level intensity (SUVmax 3.5, SUVmean 2.3). There was minimal liver and marrow uptake, with progressive washout to 60 minutes. Methods We report the first result from a 10 patient pilot trial of 68Ga-TAFC PET/CT for IAI diagnosis (NCT06105411). Inclusion criteria are adults with pulmonary IAI within 2 weeks of diagnosis. Exclusion criteria are pregnant/lactating patients or those within a week of iron infusion. 68Ga-TAFC PET/CT was performed at 15, 62, and 209 minutes after IV 139 MBq 68Ga-TAFC administration. Findings pertinent to IAI and physiologic uptake were analysed. Results The patient had probable A. fumigatus IAI in the setting of leukemia. Galactomannan and Aspergillus fumigatus PCR were positive on bronchoalveolar lavage fluid. Empiric antifungal treatment was commenced with fever resolution at 72 hours. 68Ga-TAFC-PET/CT was performed 10 days after treatment start and 4 days after microbiological diagnosis. Blood pool activity (SUVmax at 15/60/209 mins: 4.1/2.7/1.9) was demonstrated with minimal liver, spleen and gastrointestinal tract uptake (SUVmax 2.7), early renal excretion, and no marrow or other organ uptake. There was focal uptake in multiple pulmonary lesions (SUVmax 3.5), similar to blood pool activity, with synchronous washout over time. No adverse effects occurred. Conclusion Very low background physiologic biodistribution was seen in the first participant in this study. Focal low grade pulmonary uptake was visualised, likely demonstrating specific activity for A.fumigatus. Trial recruitment continues. Disclosures Abby Douglas, MBBS, Gilead Sciences: Honoraria

Association Between Metabolomics Findings and Brain Hypometabolism in Mild Alzheimer's Disease.

Alzheimer's disease (AD) is a progressive neurodegenerative condition with rising prevalence due to the aging global population. Existing methods for diagnosing AD are struggling to detect the condition in its earliest and most treatable stages. One early indicator of AD is a substantial decrease in the brain's glucose metabolism. Metabolomics can detect metabolic disturbances in biofluids, which may be advantageous for early detection of some ADrelated changes. The study aims to predict brain hypometabolism in Alzheimer's disease using metabolomics findings and develop a predictive model based on metabolomic data. The data used in this study were acquired from the Alzheimer's Disease Neuroimaging Initiative (ADNI) project. We conducted a longitudinal cohort study with three assessment time points to investigate the predictive ability of baseline metabolomic data for modeling longitudinal fluorodeoxyglucose-positron emission tomography (FDG-PET) trajectory changes in AD patients. A total number of 44 participants with AD were included. The cognitive abilities of participants were evaluated using the Alzheimer's Disease Assessment Scale (ADAS) and the Mini-Mental State Examination (MMSE), while the overall severity of dementia was measured by the Clinical Dementia Rating-Sum of Boxes (CDR-SB). We employed the ADNI's FDG MetaROIs (Meta Regions of Interest) dataset to identify AD-associated hypometabolism in the brain. These MetaROIs were selected based on areas frequently mentioned in FDG-PET studies of AD and MCI subjects. Across models, we observed consistent positive relationships between specific cholesterol esters - CE (20:3) (p = 0.005) and CE (18:3) (p = 0.0039) - and FDG-PET metrics, indicating these baseline metabolites may be valuable indicators of future PET score changes. Selected triglycerides like DG-O (16:0-20:4) also showed time-specific positive associations (p = 0.017). This research provides new insights into the disruptions in the metabolic network linked to AD pathology. These findings could pave the way for identifying novel biomarkers and potential treatment targets for AD.

Analysis and Historical Evolution of Paediatric Bone Tumours: The Importance of Early Diagnosis in the Detection of Childhood Skeletal Malignancies

Even though children’s malignant bone tumours are rare, it is crucial to understand how to identify and stage them accurately to develop an appropriate treatment plan. Ewing’s sarcoma and osteosarcoma are the two main paediatric bone malignancies and require multidisciplinary treatment involving radiologists, orthopaedists, oncologists, pathologists, and paediatricians. These neoplasms may be associated with genetic syndromes but typically occur in patients with no known germline abnormalities. With a frequency of 4.4 per million, osteosarcoma is the most common malignant bone tumour in children. Ewing’s sarcoma has an incidence of 2.5 to 3 per million, making it the second most prevalent. Clinically, these neoplasms present with pain and inflammation in the bones and joints, nocturnal pain unresponsive to drug therapy, systemic symptoms such as fever or weight loss, and persistent symptoms—all of which should prompt clinicians to initiate further diagnostic investigations. The gold standard for diagnosis includes X-ray examination and MRI, which provide an accurate assessment of tumour extension into the medullary canal and surrounding soft tissues. Fluorine-18-labelled FDG-PET scans or fluoro-deoxyglucose positron emission tomography are valuable for evaluating tumour aggressiveness and excluding metastases. A biopsy is mandatory once all other diagnostic tests have been completed. Accurate diagnosis and timely referral to an experienced clinic are essential for ensuring prompt access to treatment and improving patient outcomes.

Development and validation of a nomogram combining clinical and 18F-FDG PET/CT parameters for prediction of high-grade patterns in invasive lung adenocarcinoma

Objective: To establish and validate a nomogram based on clinical characteristics and metabolic parameters derived from 18F-fluorodeoxyglucose positron emission tomography and computed tomography (18F-FDG PET/CT) for prediction of high-grade patterns (HGP) in invasive lung adenocarcinoma. Methods: The clinical and PET/CT image data of 311 patients who were confirmed invasive lung adenocarcinoma and underwent pre-treatment 18F-FDG PET/CT scan in Beijing Hospital between October 2017 and March 2022 were retrospectively collected. The enrolled patients were divided into HGP group (196 patients) and non-HGP group (115 patients) according to the presence and absence of HGP. The data were divided into training set and validation set at 7∶3 ratio using R statistical software and simple random allocation. A nomogram prediction model was constructed in training set. The area under the curve (AUC) of receiver operating characteristic (ROC) was depicted in the training and validation set respectively for assessing the prediction efficacy. The goodness of fit, consistency between predicted and observed probability and clinical usefulness of the model were evaluated by Hosmer-Lemeshow test, calibration curve and decision curve analysis (DCA). Results: The age of 311 patients were (65.6±10.9) years and included 148 males (47.6%). In training set of 217 patients, 141 (65.0%) contained HGP while in validation set of 94 patients, 55 (58.5%) contained HGP. Gender in training set, serum carcino-embryonic antigen (CEA) in validation set, smoking history, clinical stage, cytokeratin fragments (CYFRA21-1), maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and maximum diameter (Dmax) in both sets showed significant differences between HGP and non-HGP groups (all P<0.05). The variables integrated in the model were gender, clinical stage, CYFRA21-1, SUVmean and TLG. The AUC (95%CI) of the ROC curve in training and validation set were 0.888 (0.844-0.932) and 0.925 (0.872-0.977), the sensitivity and specificity were 85.1%, 79.0% and 83.6%, 89.7%, respectively. The model showed good goodness of fit (training set: χ2=8.247, P=0.410, validation set: χ2=1.636, P=0.990). Calibration curve and DCA also indicated good consistency and clinical net benefit of the nomogram model. Conclusion: The nomogram model based on clinical features and metabolic parameters derived from 18F-FDG PET/CT could effectively predict the presence of HGP in invasive lung adenocarcinoma and be beneficial to treatment planning.

Cardiac sarcoidosis; update for the heart failure specialist.

This review presents contemporary data on epidemiology, common presentations, investigations and diagnostic algorithms, treatment and prognosis. It particularly focuses on topics of most relevance to heart failure specialists, including what left ventricle (LV) function changes can be expected after treatment and outcomes to all standard and advanced heart failure therapies. Around 5% of sarcoidosis patients have clinically manifest cardiac sarcoidosis (CS), presenting with significant arrhythmias (such as conduction disturbances and ventricular arrhythmias) or newly developed unexplained heart failure. These cardiac symptoms (including sudden cardiac death) may be the initial manifestations of CS. While cardiac magnetic resonance imaging (CMR) is the preferred method for identifying fibrosis in the myocardium, FDG-positron emission tomography (FDG-PET) helps in identifying active inflammation within the myocardium and aids in managing immunosuppressive treatment. The concept of isolated CS is much debated. However very importantly, recent data have shown that some patients diagnosed with 'clinically and imaging isolated CS' are subsequently found to have genetic cardiomyopathy. The management of CS involves a comprehensive approach including medications for immunosuppression, all standard heart failure medication and, in high-risk patient's implantable cardioverter defibrillators (ICDs). In CS patients with terminal heart failure who do not respond to medical and surgical interventions, heart transplantation and ventricular assist devices should be considered. Long-term results after transplantation are generally favorable and comparable to non-CS patients. The degree of left ventricular dysfunction remains a crucial prognostic factor in CS cases. Outcomes for CS have very significantly improved, over the last two decades due to earlier diagnosis, advanced heart failure treatments, and the strategic use of ICD therapy. Outcomes for CS have significantly improved, over the last two decades due to earlier diagnosis, advanced heart failure treatments, and the strategic use of ICD therapy.

Clinical and biochemical factors associated with amygdalar metabolic activity

We investigated clinical factors and biochemical markers associated with amygdalar metabolic activity evaluated by [18F]-fluorodeoxyglucose-positron emission tomography (FDG-PET) in 346 subjects without a history of malignant neoplasms. Univariate regression analysis revealed significant relationships between amygdalar metabolic activity and fasting plasma glucose (FPG), glycated hemoglobin, coronary artery disease (CAD) history, aspirin use, oral hypoglycemic agents (OHAs) use, and asymmetric dimethylarginine (ADMA). In multiple stepwise regression analysis, FPG and CAD history were independently associated with amygdalar metabolic activity. Moreover, in 36 patients with type 2 diabetes mellitus (T2DM), additional OHAs treatment significantly improved glycemic and metabolic parameters, and decreased ADMA concentrations. Baseline and Δpigment epithelium-derived factor (PEDF), a marker of insulin resistance, was a significant associate with Δamygdalar metabolic activity. Our study demonstrates that FPG and CAD history were independently associated with amygdalar metabolic activity in subjects without a history of malignant neoplasms. In T2DM patients, PEDF might regulate amygdala metabolic activity.

Altered brain glucose metabolism in COVID-19 disease: an activation likelihood estimation meta-analysis of PET studies.

COVID-19 disease, caused by the SARS-CoV-2 virus, has significantly altered modern society and lifestyles. We investigated its impact on brain glucose metabolism by meta-analyzing existing studies that utilized 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) scans of the brain. We conducted a systematic search of MEDLINE and EMBASE databases from inception to August 2024 for English-language publications using the keywords "positron emission tomography", and "COVID-19". We included original research articles that reported changes in brain glucose metabolism following COVID-19 disease. ALE values from these studies were aggregated and tested against a null hypothesis that anticipated a random distribution of ALE values, which proved to be significantly higher than chance. We identified nine papers that met our inclusion criteria. Significant increases in brain glucose metabolism were noted in the left anterior cingulate gyrus, right thalamus, and brainstem. In children with COVID-19 disease, decreased glucose metabolism was observed in the right and left cerebellum, left amygdala/hippocampus, left anterior cingulate gyrus, and right amygdala. In adults with COVID-19 disease, decreased metabolism was seen in the right temporal lobe, brainstem (acute phase), left occipital lobe, left and right temporal lobe (chronic phase). In conclusion, COVID-19 disease impacts brain glucose metabolism, typically manifesting as areas of decreased metabolism in 18F-FDG PET scans, though increases are also observed. These changes in metabolism vary with the patient's age and the time elapsed between the diagnosis of COVID-19 disease and the PET scan.

Diagnostic Value of Gastrin-Releasing Peptide Receptor-Targeted PET Imaging in Oncology: A Systematic Review.

Gastrin-releasing peptide receptor (GRPR), overexpressed in various cancers, is a promising target for positron emission tomography (PET). This systematic review investigated the diagnostic value of GRPR-targeted PET imaging in oncology. A systematic search was conducted on major medical databases until May 23, 2024. Keywords were modified to include clinical original studies on GRPR-targeted PET in cancer patients. Out of 1624 searched studies initially, 107 were eligible for the full-text review. Overall, data from 38 studies met inclusion criteria, investigating GRPR-targeting radiotracers in breast cancer, prostate cancer, gastrointestinal stromal tumours (GIST) and gliomas (including optic pathway glioma and glioblastoma multiforme). In breast cancer, GRPR-targeted PET effectively detected primary tumours and metastases, particularly in estrogen receptor (ER)-positive patients, and predicted treatment response. In prostate cancer, high sensitivity (up to 88%) and specificity (up to 90%) for detecting primary tumours were observed, providing added value when combined with magnetic resonance imaging (MRI). In biochemical recurrence, sites of prostate cancer were identified even at PSA levels below 0.5ng/dL. Compared with PSMA PET, GRPR-targeted PET showed comparable or superior detection rates. Considering GIST, GRPR-targeted PET imaging proved to be a valuable diagnostic tool, particularly when [18F] FDG PET results were inconclusive. Regarding gliomas, GRPR-targeted PET achieved a 100% detection rate (MRI reference), aiding localization, preoperative planning, and differentiation between recurrence and malignant transformation. GRPR-targeted PET shows promise in improving cancer diagnostics, particularly in ER-positive breast cancer, prostate cancer, and gliomas, and may enhance clinical decision-making.

CD45-PET is a robust, non-invasive tool for imaging inflammation.

Imaging inflammation holds immense potential for advancing the diagnosis, treatment and prognosis of many conditions1-3. The lack of a specific and sensitive positron emission tomography (PET) probe to detect inflammation is a critical challenge. To bridge this gap, we present CD45-PET imaging, which detects inflammation with exceptional sensitivity and clarity in several preclinical models. Notably, the intensity of theCD45-PET signalcorrelatesrobustlywith the severity of diseasein models of inflammatory lung and bowel diseases, outperforming 18F-fluorodeoxyglucose PET, the most widely used imaging modality for inflammation globally. Longitudinal CD45-PET imaging further enables precise monitoring of dynamic changes in tissue-specific inflammatory profiles. Finally, we developed a human CD45-PET probe for clinical translation that effectively detects human immune cells in a humanized mouse model. CD45-PET imaging holds substantial clinical promise, offering a tool for guidingdiagnostic and therapeuticdecisionsfor inflammatory diseases through a precise, whole-bodyassessment of the inflammationprofilesofindividual patients.

Network topology and metabolic alterations in early- and mid-stage Parkinson's disease: insights from fluorodeoxyglucose PET imaging.

Parkinson's disease (PD) is a neurodegenerative disorder with distinct metabolic alterations in the brain, which are detectable via 18F-FDG PET. This study aims to delineate glucose metabolism patterns and network topology changes across early- and mid-stage PD patients. A total of 80 PD patients (Hoehn-Yahr stages 1-3) were retrospectively analyzed, including 40 early-stage and 40 mid-stage cases, along with 40 age-matched healthy controls. All participants underwent 18F-FDG PET imaging. The brain metabolic activity was quantified, and network topology was assessed using graph theory metrics. Statistical comparisons between PD stages and control groups were performed to identify significant differences in metabolic patterns and network alterations. Early-stage PD patients exhibited hypermetabolism in regions such as the pons and thalamus, with significant differences in metabolic activity compared with controls. Mid-stage PD patients showed more extensive hypermetabolism in the pons, right cerebellum, and putamen, alongside hypometabolism in the cuneus and calcarine regions. Hub node connectivity analysis revealed decreased connectivity in temporal and occipital lobes for both stages, while the limbic and frontal lobes showed enhanced connectivity. Compared with early-stage PD, mid-stage PD had reduced connectivity in the limbic system but increased in the frontal and occipital lobes. 18F-FDG PET imaging reveals progressive metabolic disruptions and network changes in PD, offering potential biomarkers for disease staging and therapeutic targeting, while also aiding in the understanding of disease progression and guiding therapeutic interventions.

Characterization of Cutaneous Radiation Syndrome in a Mouse Model Using [18F]F- Fluorodeoxyglucose Positron Emission Tomography.

Ionizing radiation on the skin has the potential to cause various sequelae affecting quality of life and even leading to death due to multi-system failure. The development of radiation dermatitis is attributed to oxidative damage to the skin's basal layer and alterations in immune response, leading to inflammation. Past studies have shown that [18F]F-2-fluoro-2-deoxyglucose positron emission tomography-computed tomography ([18F]F-FDG PET/CT) can be used effectively for the detection of inflammatory activity, especially in conditions like hidradenitis suppurativa, psoriasis, and early atherosclerosis. Since currently there are no specific tests for radiation dermatitis, our study aimed to validate whether radiation dermatitis induced in mice can be accurately visualized and measured using [18F]F-FDG PET/CT. We induced cutaneous radiation syndrome in BALB/c mice with different radiation absorbed doses and monitored symptom development through photography, PET imaging, and histopathology, marking the first attempt at non-invasively quantifying radiation dermatitis effects at the molecular level using PET imaging. Our results showed that there were progressive changes in the dorsal skin of irradiated mice, with notable differences between those exposed to varying doses of radiation. Erythema, epilation, and desquamation were more pronounced in mice exposed to lower doses (25 Gy and 35 Gy) than at 45 Gy; however, by the third week, severe skin deterioration, including ulceration and dermal atrophy, was evident in mice irradiated with 35 Gy and 45 Gy. PET/CT imaging revealed increased [18F]F-FDG uptake in the irradiated dorsal skin area of all mice compared to controls, with more pronounced avidity for the lesion in the 25 Gy and 35 Gy than the 45 Gy. Comparison of tissue-normalized SUVMax values showed that both the 25 Gy and 35 Gy mice exhibited fourfold [18F]F-FDG uptake in the dorsal skin compared to controls, while a twofold uptake was seen at 45 Gy, thus indicating substantial metabolic changes in the dorsal skin induced by radiation exposure. Histopathological analyses correlated with the above findings, demonstrating generalized hypertrophy and epidermal thickening in all irradiated mice compared to controls, with thicker epidermis observed with higher radiation doses and increased destruction of microvasculature. In conclusion, PET/CT emerges as a successful tool for imaging cutaneous radiation syndrome, with the observed dermal changes in irradiated mice closely aligning with metabolic alterations of the affected area.

PET/CT-based target volume definition in involved-site radiotherapy for treatment of early-stage nodal follicular lymphoma.

Recent advancements in imaging, particularly 18F-fluorodeoxyglucose positron-emission tomography-computed tomography (FDG-PET/CT), have improved the detection of involved lymph nodes, thus influencing staging accuracy and potentially treatment outcomes. This study is apost hoc analysis of the GAZAI trial data to evaluate the impact of FDG-PET/CT versus computed tomography (CT) alone on radiation target volumes for involved-site radiotherapy (IS-RT) in early-stage follicular lymphoma (FL). All patients in the GAZAI trial underwent pretherapeutic FDG-PET/CT examinations, which were subject to central quality control. Lymph nodes with pathological metabolism were assessed for CT morphology. Differential regional involvement and the impact on radiation target volume for IS-RT were compared between PET/CT-based to solely CT-based staging. In 54patients with PET-positive lymph nodes after initial surgery, 170 involved lymph nodes were identified in total. FDG-PET/CT identified additionally involved lymph nodes not detected by CT in 61% of the patients, leading to asignificant change in radiation treatment fields for 30% of the cohort. Only 58% of all involved lymph nodes exhibited pathological CT morphology. The findings were robust across different Deauville score thresholds and CT morphological metrics. The findings confirm the essential role of FDG-PET/CT in accurately defining the radiation volume for treatment of early-stage follicular lymphomas with radiotherapy. These results support the integration of FDG-PET/CT into the standard diagnostic pathway and its inclusion in the service catalogue of statutory health insurance, emphasizing its importance for optimal treatment planning and the potential impact on patient outcomes.

The Role of [18F]FDG PET and Clinicopathologic Factors in Detecting and Predicting Bone Marrow Involvement in Non-Hodgkin Lymphoma.

Background/Objectives: This study evaluates the diagnostic accuracy of [18F]fluorodeoxyglucose ([18F]FDG) positron emission tomography (PET) using bone marrow biopsy (BMB) and clinical follow-up as reference standards. It further identifies predictive factors for bone marrow involvement (BMI) in non-Hodgkin lymphoma (NHL) patients. Methods: NHL patients who underwent [18F]FDG PET and BMB at diagnosis in a tertiary cancer center were included in this study. Diagnostic accuracy was analyzed, and logistic regression was performed to identify BMI predictors using Stata software version 17. A retrospective analysis of 262 NHL patients was conducted. Results: Concordance rates between [18F]FDG PET and BMB and between [18F]FDG PET and clinical follow-up were 75.6% and 88.1%, respectively. The primary cause of discordance between [18F]FDG PET and BMB was the detection of extra-iliac focal hypermetabolic bone marrow lesions by [18F]FDG PET, which were negative on BMB. The sensitivity, specificity, and accuracy of [18F]FDG PET were 62.9%, 80%, and 75.6%, respectively, with BMB as a reference, and 74.1%, 97.5%, and 88.2%, respectively, with clinical follow-up as a reference. The focal bone marrow [18F]FDG pattern was the most reliable indicator of BMI. Univariate logistic regression showed that advanced NHL stage, elevated alkaline phosphatase, thrombocytopenia, leukopenia, and elevated lactate dehydrogenase were significant predictors of BMI. Multivariate analysis revealed advanced NHL stage and thrombocytopenia as clinical predictors. Conclusions: [18F]FDG PET is a reliable tool for assessing BMI, providing comprehensive total-body evaluation and identifying extra-iliac involvement beyond the scope of BMB. The collective interpretation of molecular imaging, clinical, and biochemical factors is crucial for predicting BMI.

Longitudinal FDG-PET Metabolic Change Along the Lewy Body Continuum

Although 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a well-established cross-sectional biomarker of brain metabolism in dementia with Lewy bodies (DLB), the longitudinal change in FDG-PET has not been characterized. To investigate longitudinal FDG-PET in prodromal DLB and DLB, including a subsample with autopsy data, and report estimated sample sizes for a hypothetical clinical trial in DLB. Longitudinal case-control study with mean (SD) follow-up of 3.8 (2.3) years. Cases were recruited consecutively between 2007 and 2022 at a referral center and among the population. Patients with probable DLB or mild cognitive impairment with Lewy bodies (MCI-LB) were included. Individuals without cognitive impairment were included from a population-based cohort balanced on age and sex for comparison. All participants completed at least 1 follow-up assessment by design. Patients with MCI-LB and DLB. Rate of change in FDG-PET was assessed as standardized uptake value ratios (SUVr). Clinical progression was assessed with the Clinical Dementia Rating Sum of Boxes (CDR-SB) score. Thirty-five patients with probable DLB, 37 patients with MCI-LB, and 100 individuals without cognitive impairment were included. The mean (SD) age of the DLB and MCI-LB groups combined (n = 72) was 69.6 (8.2) years; 66 patients (92%) were men and 6 (8%) were women. At follow-up, 18 participants (49%) with MCI-LB had progressed to probable DLB. Patients with MCI-LB had a faster decline in FDG-SUVr, compared with that of participants without cognitive impairment, in the posterior cingulate, occipital, parietal, temporal, and lateral frontal cortices. The same regions showed greater metabolic decline in patients with DLB than in participants without cognitive impairment, with the addition of anterior-middle cingulate, insula, and medial frontal orbital cortices. Rates of change in FDG-PET in these brain regions were combined into a region of interest (ROI) labeled longitudinal FDG-PET LB meta-ROI. The rate of change in FDG-SUVr in the meta-ROI correlated with the rate of change in CDR-SB, and sample size estimates were reported for potential clinical trials in DLB. Findings were confirmed in the subsample with neuropathologic confirmation (n = 20). This study found that brain hypometabolism begins to evolve during the prodromal stages of DLB with changes paralleling symptomatic progression. These data may inform clinical practice and trials planning to use FDG-PET for biologic staging, monitoring disease progression, and potentially assessing treatment response.

Validation of the 2022 ACR/EULAR classification criteria for giant cell arteritis in Koran patients with giant cell arteritis.

We applied the 2022 American College of Rheumatology (ACR)/European Alliance of Association for Rheumatology (EULAR) criteria to Korean patients previously diagnosed with giant cell arteritis (GCA) according to the 1990 ACR criteria and validated its clinical efficiency. Nine patients with GCA were included in this study. The proportion of patients meeting each item of the 1990 ACR criteria and the 2022 ACR/EULAR criteria were assessed. fluorodeoxyglucose-positron emission tomography (FDG-PET), and temporal artery biopsy were performed in eight, and four of the nine patients, respectively. The median age was 65.0 years, and 77.8% of the patients were women. Seven (77.8%) patients had polymyalgia rheumatica. All nine patients were reclassified as having GCA according to the 2022 ACR/EULAR criteria. Among the 10 items of the 2022 ACR/EULAR criteria, the item contributing the most to the reclassification was elevated acute-phase reactant levels (100%), followed by new temporal headache (77.8%), and FDG-PET activity throughout the aorta (77.5%). Positive temporal artery biopsy findings were observed in 75.0% of the patients; however, only four patients underwent biopsy, which was insufficient to assess its efficacy. An item of sudden visual loss did not make a considerable contribution to the reclassification of GCA because of its rare frequency (11.1%). In this study, for the first time, we demonstrated a concordance rate of 100% between the two criteria in Korean patients previously diagnosed with GCA. Moreover, we also clarified the major contributors to the reclassification according to the 2022 ACR/EULAR criteria.

Metabolic Differences in Neuroimaging with [18F]FDG in Rats Under Isoflurane and Hypnorm-Dormicum.

Anesthesia can significantly impact positron emission tomography (PET) neuroimaging in preclinical studies. Therefore, understanding these effects is crucial for accurate interpretation of the results. In this experiment, we investigate the effect of [18F]-labeled glucose analog fluorodeoxyglucose ([18F]FDG) uptake in the brains of rats anesthetized with two commonly used anesthetics for rodents: isoflurane, an inhalation anesthetic, and Hypnorm-Dormicum, a combination injection anesthetic. Female adult Sprague Dawley rats were randomly assigned to one of two anesthesia groups: isoflurane or Hypnorm-Dormicum. The rats were submitted to dynamic [18F]FDG PET scan. The whole brain [18F]FDG standard uptake value (SUV) and the brain voxel-based analysis were performed. The dynamic [18F]FDG data revealed that the brain SUV was 38% lower in the isoflurane group after 40 min of image (2.085 ± 0.3563 vs. 3.369 ± 0.5577, p = 0.0008). In voxel-based analysis between groups, the maps collaborate with SUV data, revealing a reduction in [18F]FDG uptake in the isoflurane group, primarily in the cortical regions, with additional small increases observed in the midbrain and cerebellum. The observed differences in [18F]FDG uptake in the brain may be attributed to variations in metabolic activity. These results underscore the necessity for careful consideration of anesthetic choice and its impact on neuroimaging outcomes in future research.

Transient lymphocyte count decrease correlates with oncolytic adenovirus efficacy in humans: mechanistic and biomarker findings from TUNIMO phase I trial

BackgroundOncolytic viruses (OVs) are promising immunotherapeutics to treat immunologically cold tumors. However, research on the mechanism of action of OVs in humans and clinically relevant biomarkers is still sparse. To...

Reconfigured metabolism brain network in asymptomatic Creutzfeldt-Jakob disease.

Investigating brain metabolic networks is crucial for understanding the pathogenesis and functional alterations in Creutzfeldt-Jakob disease (CJD). However, studies on presymptomatic individuals remain limited. This study aimed to examine metabolic network topology reconfiguration in asymptomatic carriers of the PRNP G114V mutation. Seven asymptomatic PRNP G114V mutation carriers from a familial genetic CJD (gCJD) cohort, 43 CJD patients, and 35 healthy controls were included. All participants underwent neuropsychological assessments, genetic testing, and 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET)/MRI scans. Voxel-based gray matter volume and FDG PET standardized uptake value ratios (SUVRs) were analyzed between asymptomatic PRNP G114V mutation carriers and healthy controls and between CJD patients and controls. Graph theory and sparse inverse covariance estimation (SICE) were used to assess the whole-brain metabolic connectomes and topological properties. Spatial independent component analysis (ICA) was used to evaluate subnetworks, including the default mode network (DMN), salience network (SN), and central executive network (CEN). With respect to global properties, assortativity was significantly increased in asymptomatic carriers, which was consistent with the findings in CJD patients. We revealed lost hubs in the right anterior cingulate, left ventral prefrontal lobe, left parahippocampal gyrus, and left lingual gyrus and reconfigured hubs in prefrontal lobes, including right ventromedial prefrontal cortex, right anterior prefrontal cortex, and right middle frontal gyrus of the orbit in asymptomatic carriers compared with healthy controls, which overlapped with the comparisons between CJD patients and controls. Alterations in the local parameters and metabolic connectivity in the left parahippocampal gyrus were most pronounced. Among the subnetworks, asymptomatic carriers presented higher assortativity and lower hierarchy in the SN, whereas the global parameters of the DMN and CEN were not significantly altered. The DMN and SN showed partial hypoconnectivity and hyperconnectivity, whereas the CEN mainly showed significantly enhanced connectivity in asymptomatic PRNP carriers. This study revealed altered brain metabolic topology and connectomics in asymptomatic PRNP G114V mutation carriers, which could be detected before gray matter or regional metabolic changes, suggesting that metabolism topology reconfiguration may serve as a sensitive imaging biomarker for investigating early CJD pathological changes.