Diagnosis and Evaluation of Treatment Response in Relapsing Polychondritis Using 18F-FDG PET/CT.

A 58-year-old man presenting with dyspnea, weight loss, and night sweating underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) because of a suspicion of malignancy. 18F-FDG PET/CT demonstrated mild to moderate uptake on nasal, cricoid, and tracheobronchial tree cartilages and costovertebral junctions. The diagnosis was relapsing polychondritis, which is a rare multisystem disease characterized by inflammation of cartilage. In addition, subsequent 18F-FDG PET/CT after treatment showed complete metabolic response.

Late 68Ga PSMA-positive Pancreatic Metastasis From Renal Cell Carcinoma in a Patient with Metastatic Prostate Cancer: A Mission Impossible.

We present the case of a patient with newly diagnosed high-risk prostate cancer. The patient underwent nephrectomy for renal cell carcinoma (RCC) in 2009. The prostate-specific membrane antigen (PSMA) scan revealed a primary tumor with seminal vessel involvement, PSMA-positive regional lymph nodes, several nodular lung lesions with mild PSMA uptake, PSMA-positive mediastinal lymph nodes, and a PSMA-positive mass in the pancreatic head. Ultrasound-guided biopsy was performed for the pancreatic lesions revealing metastasis from a RCC. Simultaneous treatment for prostate cancer and metastatic RCC was initiated. To separate metastatic sites for both primaries, we attempted to use fluorodeoxyglucose positron emission tomography/computed tomography, which was moderately positive for the pancreatic mass but not for the other locations. RCC is a 68Ga PSMA-positive tumor; the synchronous combination of RCC with prostate cancer can be confusing and requires more complex clinical interpretation.

Misdiagnosis of a Drain-site Hernia Containing Fallopian Tube Fimbria on 18F-FDG PET/CT.

In a 55-year-old woman with sigmoid colon cancer, a subcutaneous mass in the left lower abdomen was incidentally found and gradually enlarged. For further diagnosis and staging, an 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography scan was performed, which revealed a subcutaneous mass in the left lower abdomen with mild uptake of 18F-FDG, suggesting the possibility of metastasis. However, post-surgery and pathological confirmation, this mass was diagnosed as a drain-site hernia containing fallopian tube fimbria, which is extremely rare but should be considered in the differential diagnosis of subcutaneous mass in the lower abdomen.

18F-FDG and 68Ga-FAPI-04 PET/CT Findings of a Rare Epithelial-myoepithelial Carcinoma Arising From Ex Pleomorphic Adenoma of Parotid.

Epithelial-myoepithelial carcinoma (EMC) is a rare low-grade salivary gland neoplasm. Distant metastasis is rare, and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has been used to determine the metastatic disease in EMC. 68Ga-fibroblast activation protein inhibitors (FAPI) PET/CT is a promising imaging modality for diagnostic and theognostic purposes in various malignancies. Comparison studies with 18F-FDG have investigated the role of 68Ga-FAPI PET/CT. Herein, we present 18F-FDG and 68Ga-FAPI-04 PET/CT findings of a 51-year-old woman with metastatic EMC arising from ex-pleomorphic adenoma of the parotid.

Jejunal Undifferentiated Spindle Cell Sarcoma with Intussusception Revealed by 18F-FDG PET/CT.

Spindle cell sarcoma is a malignant tumor with low incidence. They can occur in the soft tissue, bone, or viscera. The characteristics of morphology, density, and metabolism of spindle cell sarcoma are related to the location of the lesion. A 61-year-old woman presented with vomiting after eating for 2 weeks. Signs of peritoneal irritation were involved, but no response for symptomatic treatment included antiemetic and antispasmodic therapy. Abdominal computed tomography (CT) indicated a mass in the intestinal tract in the pelvic cavity. Then, 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/CT was performed, which interestingly detected a jejunal malignancy mass in the left upper abdomen with annular high uptake of 18F-FDG, which was complicated by intussusception and intestinal obstruction. Finally, the jejunal mass was pathologically clarified as an undifferentiated spindle cell sarcoma.

Isolated Diffuse Bone Marrow Metastases From Signet-ring Cell Gastric Carcinoma.

A 71-year-old female patient with a known history of signet-ring cell carcinoma presented with diffuse bone pain and anemic symptoms. An 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography study revealed diffuse heterogeneous hypermetabolic sclerotic lesions in the axial and proximal appendicular skeleton. No other 18F-FDG-avid lesions were detected. Subsequent bone marrow biopsy confirmed the diagnosis of metastatic carcinoma originating from the gastric primary site. Palliative treatment was initiated; however, the patient's condition deteriorated, and she succumbed to the disease two months later.

Comparison of 18F-FDG PET/CT and 18F-DOTATATE PET/CT in the diagnosis of multiple metastases in rectal neuroendocrine neoplasms.

This case report describes a 62-year-old male with a notable medical history, including surgically treated bladder cancer and the suspicion of metastatic disease. He underwent 18F-FDG PET/CT imaging as part of the initial diagnostic workup, which identified several marginally hypodense hepatic lesions. These lesions exhibited metabolic activity that was slightly lower than the surrounding hepatic parenchyma, raising concerns for metastatic involvement. Subsequent 18F-DOTATATE PET/CT imaging significantly expanded the diagnostic perspective by identifying multiple somatostatin receptor (SSTR)-positive lesions, not only in the liver but also in lymph nodes and bones. This marked an important diagnostic advancement over the initial FDG PET/CT findings, showcasing the superior sensitivity of 18F-DOTATATE PET/CT in detecting SSTR-expressing tumors. Pathological evaluation after these imaging studies confirmed the diagnosis of a rectal neuroendocrine tumor (NET) with extensive hepatic metastasis, altering the clinical management and therapeutic approach for the patient. This case underscores the pivotal role of integrating 18F-DOTATATE and FDG PET/CT in the diagnostic and therapeutic management of neuroendocrine tumors, highlighting the complementary nature of these imaging modalities. The findings advocate for the use of 18F-DOTATATE PET/CT in cases where NETs are suspected, particularly for its enhanced sensitivity in detecting SSTR-positive lesions across various sites, thereby facilitating a more comprehensive disease assessment and informed therapeutic planning.

Cerebral hypometabolism in a pediatric patient with clinically resolved posterior reversible encephalopathy syndrome.

A 4-year-old boy with Nuclear factor-kappa B Essential Modulator deficiency syndrome presented with encephalopathy post haematopoietic stem cell transplantation. MRI demonstrated T2/FLAIR-hyperintensities in the posterior cerebral cortex concerning for posterior reversible encephalopathy syndrome. Clinical improvement was appreciated following withdrawal of the suspected offending pharmacological agent (Cyclosporine). An 18F-FDG PET/CT performed 2 months later to screen for post-transplant lymphoproliferative disease demonstrated markedly reduced FDG uptake in the posterior cerebral cortex, involving the parietal and occipital lobes. We describe, to the best of our knowledge, the first case of profound cerebral hypometabolism in a child with clinically resolved posterior reversible encephalopathy syndrome.

PET Imaging in Chimeric Antigen Receptor T-Cell Trafficking.

The evolving field of chimeric antigen receptor (CAR) T-cell therapy, though promising, necessitates more comprehensive imaging methods to enhance therapeutic effectiveness and track cell trafficking in patients and ex vivo. This review examines the application of PET imaging in CAR T-cell trafficking and optimizing their therapeutic impact. The application of PET imaging using various radiotracers is promising in providing evaluation of CAR T-cell interaction within the host, thereby facilitating strategies for improved patient outcomes. As this technology progresses, further innovative strategies to streamline assessments of immunotherapeutic effectiveness are anticipated.

Comparison of the Performance of [18F]-FDG PET/CT and [18F]-FDG PET/MRI for Lymph Node Metastasis in Breast Cancer: A Systematic Review and Meta- Analysis.

OBJECTIVE: The primary objective of this study was to conduct a comparative analysis of the diagnostic efficacy of [18F]-FDG PET/CT and [18F]-FDG PET/MRI in the detection of breast cancer lymph node metastasis. METHODS: We conducted a comprehensive search on PubMed, Embase, and Web of Science databases, encompassing eligible articles until March 2023. The pooled sensitivity and specificity for [18F]-FDG PET/CT and [18F]-FDG PET/MRI have been reported as estimates with 95% Confidence Intervals (CIs) using a bivariate random-effect model. Utilizing the I square (I2) statistic, heterogeneity among pooled studies was evaluated. The quality assessment of the included studies was conducted using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) methodology. RESULTS: We included 18 studies (2057 patients). The sensitivity, specificity, and AUC (Area Under the Curve) values of [18F]-FDG PET/CT for overall lymph node metastasis in breast cancer have been found to be 0.58 (0.39 - 0.75), 0.83 (0.69-0.92), and 0.79 (0.75-0.82), respectively. Correspondingly, the values for [18F]-FDG PET/MRI were found to be 0.76 (0.60-0.88), 0.85 (0.77-0.91), and 0.89 (0.86-0.91), respectively. The sensitivity, specificity, and AUC values of [18F]-FDG PET/CT for axillary lymph node metastasis in breast cancer were 0.52 (0.37-0.67), 0.84 (0.68-0.92), and 0.73 (0.69-0.76), respectively. Correspondingly, the values for [18F]-FDG PET/MRI were 0.84 (0.76-0.89), 0.87 (0.75-0.94), and 0.86 (0.83-0.89), respectively. CONCLUSION: This study has suggested [18F]-FDG PET/MRI to have greater diagnostic power than [18F]-FDG PET/CT in detecting lymph node metastasis in breast cancer. However, the [18F]-FDG PET/MRI results have been obtained from a small sample size study, and more and larger prospective studies are needed for further confirmation on this issue.

Presentation of metastatic carotid body paraganglioma on F-18 FDG PET/CT: a rare disease.

Carotid body paraganglioma is a slow growing tumor of head and neck region. It can rarely be malignant in nature which is characterized by distant metastases on anatomical imaging. We share an interesting presentation of a malignant carotid body on F-18 FDG PET/CT in form of liver and skeletal metastases.

GWO+RuleFit: rule-based explainable machine-learning combined with heuristics to predict mid-treatment FDG PET response to chemoradiation for locally advanced non-small cell lung cancer.

OBJECTIVE: Vital rules learned from FDG-PET radiomics of tumor subregional response can provide clinical decision support for precise treatment adaptation. We combined a rule-based machine learning (ML) model (RuleFit) with a heuristic algorithm (Gray Wolf Optimizer, GWO) for mid-chemoradiation FDG-PET response prediction in patients with locally advanced non-small cell lung cancer. Approach: Tumors subregions were identified using K-means clustering. GWO+RuleFit consists of three main parts: (i) a random forest is constructed based on conventional features or radiomic features extracted from tumor regions or subregions in FDG-PET images, from which the initial rules are generated; (ii) GWO is used for iterative rule selection; (iii) the selected rules are fit to a linear model to make predictions about the target variable. Two target variables were considered: a binary response measure (∆SUVmean⩾20% decline) for classification and a continuous response measure (∆SUVmean) for regression. GWO+RuleFit was benchmarked against common ML algorithms and RuleFit, with leave-one-out cross-validated performance evaluated by the area under the receiver operating characteristic curve (AUC) in classification and root-mean-square error (RMSE) in regression. Main results: GWO+RuleFit selected 15 rules from the radiomic feature dataset of 23 patients. For treatment response classification, GWO+RuleFit attained numerically better cross-validated performance than RuleFit across tumor regions and sets of features (AUC:0.58-0.86 vs. 0.52-0.78, p=0.170-0.925). GWO+Rulefit also had the best or second-best performance numerically compared to all other algorithms for all conditions. For treatment response regression prediction, GWO+RuleFit (RMSE:0.162-0.192) performed better numerically for low-dimensional models (p=0.097-0.614) and significantly better for high-dimensional models across all tumor regions except one (RMSE:0.189-0.219, p<0.004). Significance: The GWO+RuleFit selected rules were interpretable, highlighting distinct radiomic phenotypes that modulated treatment response. GWO+Rulefit achieved parsimonious models while maintaining utility for treatment response prediction, which can aid clinical decisions for patient risk stratification, treatment selection, and biologically driven adaptation. Clinical trial: NCT02773238.

Advancing Cancer Theranostics Through Integrin αVß3-Targeted Peptidomimetic IAC: From Bench to Bedside.

Introduction: The expression of alpha-five beta-three (αVß3) integrins is upregulated in various malignancies undergoing angiogenesis. The development of integrin antagonists as diagnostic probes makes the αVß3 integrin a suitable candidate for targeting tumor angiogenesis. The goal of this study was to optimize the radiolabeling and evaluate the potential of conjugated integrin antagonist carbamate (IAC), a peptidomimetic, as a theranostic radiopharmaceutical for targeting tumor angiogenesis. Methodology: Radiolabeling of DOTAGA [2,2',2" -{10-(2,6-dioxotetrahydro-2H-pyran-3-yl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl} triacetic-acid]-IAC with [68Ga]Ga, [177Lu]Lu, and [225Ac]Ac was optimized. The binding affinity (Kd) of DOTAGA-IAC for the αVß3 receptor and cancer cell lines was quantified. The biodistribution studies were conducted in healthy Wistar rats. Dosimetry analysis was performed on [177Lu]Lu-DOTAGA-IAC distribution data. A pilot study of [68Ga]Ga-DOTAGA-IAC and [18F]FDG Positron Emission Tomography (PET/CT) imaging was performed in five patients with histopathologically confirmed breast cancer. PET/CT findings were compared between [68Ga]Ga-DOTAGA-IAC and [18F]FDG in these patients. Results: Radiopharmaceuticals were prepared with high radiochemical purity (>99.9%). Kd and Bmax measurements were 15.02 nM and 417 fmol for αVß3 receptor protein: 115.7 nM and 295.3 fmol for C6 glioma cells. Biodistribution studies in rats suggested the excretion via kidneys and partially through the hepatobiliary route. The effective dose of [177Lu]Lu-DOTAGA-IAC was found to be 0.17 mSv/MBq. The dynamic study in patients revealed the optimal imaging time to be 30-35 mins postadministration. Out of the cohort, [68Ga]Ga-DOTAGA-IAC detected the primary lesions in all five patients with a mean standard uptake value (SUVmax) of 3.94 ± 0.58 compared with [18F]FDG (SUVmax 13.8 ± 6.53). Conclusion: The study demonstrates that DOTAGA-IAC exhibits strong binding to αVß3 integrin, positioning it as a promising PET agent for assessing primary and metastatic cancers. The outcomes from the pilot study suggest the potential of [68Ga]Ga-DOTAGA-IAC PET/CT in breast carcinoma diagnosis. While recognizing the theranostic potential of DOTAGA-IAC for αVß3 integrin-expressing tumors, further clinical investigations are warranted to comprehensively assess therapeutic efficacy.

18F-FDG PET/CT findings of paratesticular alveolar rhabdomyosarcoma.

Rhabdomyosarcoma (RMS) originates from primitive mesenchymal cells and is the most common soft tissue tumor in childhood. 18F-fluoro-deoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) has been reported to be valuable in RMS staging and risk stratification. Paratesticular RMS is a relatively uncommon form of RMS, most of which are of the embryonal histologic type. Paratesticular alveolar RMS is associated with aggressive behavior, high metastatic potential, and poor outcomes. To the best of our knowledge, 18F-FDG PET/CT imaging findings of paratesticular alveolar RMS have never been described. Here, we report on a 16-year-old boy's rare paratesticular alveolar RMS with multiple metastases and its findings on 18F-FDG PET/CT. This case also demonstrates the potential value of 18F-FDG PET/CT in RMS staging and treatment decisions, and may aid in the differential diagnosis.

A bibliometric analysis based on hotspots and frontier trends of positron emission tomography/computed tomography utility in bone and soft tissue sarcoma.

Purpose: This study aimed to analyze articles on the diagnosis and treatment of bone and soft tissue sarcoma using positron emission tomography (PET)/computed tomography (CT) published in the last 13 years. The objective was to conduct a bibliometric analysis and identify the research hotspots and emerging trends. Methods: Web of Science was used to search for articles on PET/CT diagnosis and treatment of bone and soft tissue sarcoma published from January 2010 to June 2023. CiteSpace was utilized to import data for bibliometric analysis. Results: In total, 425 relevant publications were identified. Publications have maintained a relatively stable growth rate for the past 13 years. The USA has the highest number of published articles (139) and the highest centrality (0.35). The UDICE-French Research Universities group is the most influential institution. BYUN BH is a prominent contributor to this field. The Journal of Clinical Oncology has the highest impact factor in the field. Conclusion: The clinical application of PET/CT is currently a research hotspot. Upcoming areas of study concentrate on the merging of PET/CT with advanced machine learning and/or alternative imaging methods, novel imaging substances, and the fusion of diagnosis and therapy. The use of PET/CT has progressively become a crucial element in the identification and management of sarcomas. To confirm its efficacy, there is a need for extensive, multicenter, prospective studies.

Baseline and early 18F-FDG PET/CT evaluations as predictors of progression-free survival in metastatic breast cancer patients treated with targeted anti-CDK therapy.

BACKGROUND: Exploring the value of baseline and early 18F-FDG PET/CT evaluations in prediction PFS in ER+/HER2- metastatic breast cancer patients treated with a cyclin-dependent kinase inhibitor in combination with an endocrine therapy. METHODS: Sixty-six consecutive breast cancer patients who underwent a pre-therapeutic 18F-FDG PET/CT and a second PET/CT within the first 6 months of treatment were retrospectively included. Metabolic tumour volume (MTV) and total lesion glycolysis (TLG) and Dmax, which represents tumour dissemination and is defined as the distance between the two most distant lesions, were computed. The variation in these parameters between baseline and early evaluation PET as well as therapeutic evaluation using PERCIST were assessed as prognosticators of PFS at 18 months. RESULTS: The median follow-up was equal to 22.5 months. Thirty progressions occurred (45.4%). The average time to event was 17.8 ± 10.4 months. At baseline, Dmax was the only predictive metabolic parameter. Patients with a baseline Dmax ≤ 18.10 cm had a significantly better 18 m-PFS survival than the others: 69.2% (7.7%) versus 36.7% (8.8%), p = 0.017. There was no association between PERCIST evaluation and 18 m-PFS status (p = 0.149) and there was no difference in 18 m-PFS status between patients classified as complete, partial metabolic responders or having stable metabolic disease. CONCLUSION: Disease spread at baseline PET, as assessed by Dmax, is predictive of an event occurring within 18 months. In the absence of early metabolic progression, which occurs in 15% of patients, treatment should be continued regardless of the quality of the initial response to treatment.

Relationships between plasma biomarkers, tau PET, FDG PET, and volumetric MRI in mild to moderate Alzheimer's disease patients.

INTRODUCTION: The "A/T/N" (amyloid/tau/neurodegeneration) framework provides a biological basis for Alzheimer's disease (AD) diagnosis and can encompass additional changes such as inflammation ("I"). A spectrum of T/N/I imaging and plasma biomarkers was acquired in a phase 2 clinical trial of rasagiline in mild to moderate AD patients. We evaluated these to understand biomarker distributions and relationships within this population. METHODS: Plasma biomarkers of pTau-181, neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), other inflammation-related proteins, imaging measures including fluorodeoxyglucose (FDG) positron emission tomography (PET), flortaucipir PET, and volumetric magnetic resonance imaging (MRI), and cognitive endpoints were analyzed to assess characteristics and relationships for the overall population (N = 47 at baseline and N = 21 for longitudinal cognitive comparisons) and within age-decade subgroups (57-69, 70-79, 80-90 years). RESULTS: Data demonstrate wide clinical and biomarker heterogeneity in this population influenced by age and sex. Plasma pTau-181 and GFAP correlate with tau PET, most strongly in left inferior temporal cortex (p = 0.0002, p = 0.0006, respectively). In regions beyond temporal cortex, tau PET uptake decreased with age for the same pTau-181 or GFAP concentrations. FDG PET and brain volumes correlate with tau PET in numerous regions (such as inferior temporal: p = 0.0007, p = 0.00001, respectively). NfL, GFAP, and all imaging modalities correlate with baseline MMSE; subsequent MMSE decline is predicted by baseline parahippocampal and lateral temporal tau PET (p = 0.0007) and volume (p = 0.0006). Lateral temporal FDG PET (p = 0.006) and volume (p = 0.0001) are most strongly associated with subsequent ADAS-cog decline. NfL correlates with FDG PET and baseline MMSE but not tau PET. Inflammation biomarkers are intercorrelated but correlated with other biomarkers in only the youngest group. DISCUSSION: Associations between plasma biomarkers, imaging biomarkers, and cognitive status observed in this study provide insight into relationships among biological processes in mild to moderate AD. Findings show the potential to characterize AD patients regarding likely tau pathology, neurodegeneration, prospective clinical decline, and the importance of covariates such as age. Highlights: Plasma pTau-181 and GFAP correlated with regional and global tau PET in mild to moderate AD.NfL correlated with FDG PET and cognitive endpoints but not plasma pTau-181 or tau PET.Volume and FDG PET showed strong relationships to tau PET, one another, and cognitive status.Temporal volumes most strongly predicted decline in both MMSE and ADAS-cog.Volume and plasma biomarkers can enrich for elevated tau PET with age a significant covariate.

Head-to-head comparison of [68Ga]Ga-FAPI-04 PET and [18F]FDG PET in the detection of cancer recurrence: a systematic review and meta-analysis.

Background: The comparative diagnostic performance of [68Ga]Ga-fibroblast activation protein inhibitors-04 {[68Ga]Ga-FAPI-04} positron emission tomography (PET) and fluorodeoxyglucose F 18 {[18F]FDG} PET in identifying cancer recurrence remains uncertain. The purpose of our study was to compare the diagnostic performance of [68Ga]Ga-FAPI-04 PET and [18F]FDG PET imaging in cancer recurrence. Methods: Up until March 1, 2024, we searched PubMed, Embase, and Web of Science for pertinent papers. Studies examining the diagnostic utility of [68Ga]Ga-FAPI-04 PET and [18F]FDG PET for cancer recurrence were included. Using a bivariate fixed-effect model and random-effect model, the pooled sensitivity and specificity for [68Ga]Ga-FAPI-04 PET and [18F]FDG PET were reported as estimates with 95% confidence intervals (CIs). The I2 statistic was used to evaluate the heterogeneity among the pooled studies. The included studies' quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) approach. Results: In all, 508 papers were found during the first search; ultimately, 12 studies totaling 224 patients were included. The pooled sensitivity of [68Ga]Ga-FAPI-04 PET and [18F]FDG PET for cancer recurrence were 0.97 (95% CI: 0.90-1.00) and 0.69 (95% CI: 0.60-0.77). The pooled sensitivity of [68Ga]Ga-FAPI-04 PET and [18F]FDG PET for gastrointestinal cancer recurrence were 1.00 (95% CI: 0.97-1.00) and 0.57 (95% CI: 0.42-0.74). The pooled specificity of [68Ga]Ga-FAPI-04 PET and [18F]FDG PET for gastrointestinal cancer recurrence were 0.66 (95% CI: 0.15-1.00) and 0.46 (95% CI, 0.00-1.00). Conclusions: Based on the previous studies, [68Ga]Ga-FAPI-04 PET shows higher sensitivity compared to [18F]FDG PET in detecting tumor recurrence, especially in detecting gastrointestinal cancer recurrence. [68Ga]Ga-FAPI-04 PET shows similar specificity compared to [18F]FDG PET in detecting gastrointestinal cancer recurrence. The detection results, however, came from investigations using modest sample numbers. In this matter, more extensive prospective study is required.

Functional imaging in late-onset epilepsy: A focused review.

INTRODUCTION: About 25 % of new-onset epilepsies are diagnosed after age 65. Late-onset epilepsy (LOE) is predicted to become a major healthcare problem in the next 15 years as the global population increases and ages. Neurodegenerative disorders account for 10-20 % of LOE, while over 20 % of these patients have an unknown etiology. Established diagnostic tools such as FDG-PET and novel biomarkers of neurodegeneration including amyloid and tau PET hold a lot of promise in diagnosing and ruling out neurodegenerative disorders in these patients. METHODS: We conducted a literature search to identify articles involving LOE populations and using one or more functional neuroimaging techniques. RESULTS: A total of 5 studies were identified through Boolean searching and snowballing. These were highly heterogenous with respect to operational definitions of LOE, analyses and interpretation pipelines. CONCLUSION: While there is some evidence for feasibility and usefulness of FDG- and Amyloid PET in LOE, methodological heterogeneities in the available literature preclude any notable conclusions. Future research in this field will benefit from a consensus on epilepsy-specific analysis and interpretation guidelines for amyloid and tau PET.

Sedation-free pediatric [18F]FDG imaging on totalbody PET/CT with the assistance of artificial intelligence.

PURPOSE: While sedation is routinely used in pediatric PET examinations to preserve diagnostic quality, it may result in side effects and may affect the radiotracer's biodistribution. This study aims to investigate the feasibility of sedation-free pediatric PET imaging using ultra-fast total-body (TB) PET scanners and deep learning (DL)-based attenuation and scatter correction (ASC). METHODS: This retrospective study included TB PET (uExplorer) imaging of 35 sedated pediatric patients under four years old to determine the minimum effective scanning time. A DL-based ASC method was applied to enhance PET quantification. Both quantitative and qualitative assessments were conducted to evaluate the image quality of ultra-fast DL-ASC PET. Five non-sedated pediatric patients were subsequently used to validate the proposed approach. RESULTS: Comparisons between standard 300-second and ultra-fast 15-second imaging, CT-ASC and DL-ASC ultra-fast 15-second images, as well as DL-ASC ultra-fast 15-second images in non-sedated and sedated patients, showed no significant differences in qualitative scoring, lesion detectability, and quantitative Standard Uptake Value (SUV) (P = ns). CONCLUSIONS: This study demonstrates that pediatric PET imaging can be effectively performed without sedation by combining ultra-fast imaging techniques with a DL-based ASC. This advancement in sedation-free ultra-fast PET imaging holds potential for broader clinical adoption.