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ApoE -/- mice are a widely used preclinical model of atherosclerosis, potentially accelerated by a Western diet (WD) or uremia. We aimed to compare hybrid 18 F-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography-magnetic resonance (PET-MR) and immunostaining in ApoE -/- models of accelerated atherosclerosis. Five groups were studied: standard diet-fed ApoE -/- (n = 7), standard diet-fed and uremic ApoE -/- (n = 7), WD ApoE -/- (n = 7), WD and uremic ApoE -/- (n = 6), and control C57BL/6J mice (n = 6). Uremia was induced by electrocoagulation of the right kidney at 8 weeks old, followed 2 weeks later by a contralateral nephrectomy. 18 F-FDG PET-MR imaging and histological staining (anti-CD4, -CD8, -CD11c, -CD20, -CD31, -CD68, -CD163, -interferon-γ, interleukin-1α, -1β, -6, -17 A antibodies) were performed in 18-week-old mice, i.e., 8 weeks after 5/6 nephrectomy and/or WD.  18 F-FDG uptake was similar in all groups. In contrast, histological staining highlighted higher percentages of CD8-, CD68-, or CD11c-positive cells in ApoE -/- aortic samples than in wild-type aortic samples. In addition, immunostaining revealed some differences between ApoE -/- mouse groups. Only the WD seemed to contribute to these differences. Using immunostaining, WD appeared to be a stronger accelerator of atherosclerosis than uremia. However, 18 F-FDG PET-MR imaging failed to demonstrate in vivo increased aortic glucose uptake in these models., Competing Interests: Declarations Ethical approval All animal procedures were approved by the regional animal ethics committee (Comité d’Éthique NOrmand en Matière d’EXpérimentation Animale, CENOMEXA 054, n°29982) and were performed in accordance with the European directive 2010/63/EU on the protection of animals used for scientific purposes and specific French laws (decree n°2013–118). Competing interests The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Background: Increased thermogenic activity has shown to be a promising target for treating and preventing obesity and type 2 diabetes (T2DM). Little is known about the muscular influence on nonshivering thermogenesis (NST), and it remains unclear whether physical training and potential metabolic improvements could be associated with changes in this type of thermogenic activity., Objective: The present study aimed to assess muscular NST activity in overweight and T2DM before and after a combined training period (strength training followed by aerobic exercise)., Methods: Nonshivering cold-induced 18-fluoroxyglucose positron emission computed tomography (18F-FDG PET/CT) was performed before and after 16 weeks of combined training in 12 individuals with overweight and T2DM. The standard uptake value (SUV) of 18F-FDG was evaluated in skeletal muscles, the heart and the aorta., Results: Muscles in the neck region exhibit higher SUV pre- and posttraining. Furthermore, a decrease in glucose uptake by the muscles of the lower and upper extremities and in the aorta was observed after training when adjusted for brown adipose tissue (BAT). These pre-post effects are accompanied by increased cardiac SUV and occur concurrently with heightened energy expenditure and metabolic improvements., Conclusions: Muscles in the neck region have greater metabolic activity upon exposure to cold. In addition, combined training appears to induce greater NST, favoring the trunk and neck region compared to limbs based on joint work and adaptations between skeletal muscles and BAT., (© 2024 Scandinavian Society of Clinical Physiology and Nuclear Medicine.)

Background: Echocardiography, cardiac magnetic resonance and cardiac 18 fluorodeoxyglucose positron emission tomography (FDG-PET) imaging play key roles in the diagnosis and management of cardiac sarcoidosis (CS), but the relative value of each modality in predicting outcomes has yet to be determined. This study sought to determine the prognostic importance of multimodality imaging data over and above demographic characteristics and left ventricular ejection fraction (LVEF)., Methods: Consecutive patients newly diagnosed with CS were included. Parameters evaluated included echocardiographic regional wall motion abnormality (RWMA), myocardial strain, LVEF, right ventricular ejection fraction (RVEF), late gadolinium enhancement (LGE) extent, SUVmax and RV FDG uptake. The primary endpoint was a composite of all-cause mortality and serious ventricular arrhythmia., Results: The study population consisted of 208 patients with mean age of 55±13 years and LVEF of 55±12%. During a median follow-up period of 46 (IQR: 18-55) months, 14 patients died and 28 suffered serious ventricular arrhythmias. On multivariable analysis, RWMA (HR for RWMA presence 2.55, 95% CI 1.27 to 5.28, p=0.008), LGE extent (HR per 1% increase 1.02, 95% CI 1.00 to 1.04, p=0.018), RVEF (HR per 1% decrease 0.97, 95% CI 0.94 to 0.99, p=0.008) and RV FDG uptake (HR for RV FDG presence 2.48, 95% CI 1.15 to 5.33, p=0.020) were independent predictors of the primary endpoint, while LVEF was not predictive. The risk of adverse events was significantly greater in those with LGE extent ≥15% (HR for ≥15% presence 3.96, 95% CI 2.17 to 7.23, p<0.001)., Conclusion: In our CS population, RWMA, LGE extent, RVEF and RV FDG uptake were strong independent predictors of an adverse outcome. These findings offer an important insight into the key multimodality imaging parameters that may be used in a future risk stratification model of patients with CS., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The aim of this study was to compare the diagnostic value of 18 F-FDG PET or PET/CT with FDG PET/MR in patients with inflammatory bowel disease (IBD)., Methods: A comprehensive search was performed in PubMed for studies reporting the diagnostic performance of FDG PET (PET/CT) and FDG PET/MR in IBD from the inception of the database to March 14, 2024, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Fourteen studies were included in this systematic review and meta-analysis. Pooled estimates of segment-based sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio for FDG PET (PET/CT) and FDG PET/MR were calculated alongside 95% confidence intervals. Summary receiver operating characteristic (SROC) curves were plotted, and the area under the SROC curve was determined alongside the Q * index., Results: The segment-based pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the SROC curve of FDG PET (PET/CT) for diagnosing IBD (9 studies) were 0.81, 0.86, 5.76, 0.22, 31.92, and 0.92, respectively. Those of FDG PET/MR (5 studies) were 0.78, 0.92, 10.97, 0.25, 51.79, and 0.95. There was no significant difference in the abilities of detecting or excluding IBD between FDG PET (PET/CT) and FDG PET/MR., Conclusions: For diagnostic value in patients with IBD, there was no significant difference between FDG PET (PET/CT) and FDG PET/MR. Both FDG PET (PET/CT) and FDG PET/MR have demonstrated high diagnostic performance for accurate diagnosing in patients with IBD., Competing Interests: Conflicts of interest and sources of funding: none declared. This study was supported in part by China Medical University Hospital (DMR-113-048, DMR-113-060, DMR-113-061)., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Hematogenous or lymphatic intraureteral metastasis from distant primary cancer is very rare. We present contrast-enhanced CT and FDG PET/CT findings in a case of intraureteral metastasis from colonic adenocarcinoma 3 years after colectomy. The intraureteral showed moderate enhancement on contrast-enhanced CT and increased FDG uptake on PET/CT mimicking a primary ureteral carcinoma. This case suggests that metastatic tumor of the ureter should be considered in the differential diagnosis in patients with hypermetabolic ureteral lesion and known malignancy., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Uveitis is a group of inflammatory ocular pathologies. Endotoxin-Induced Uveitis (EIU) model represent a well-known model induced by administration of Lipopolysaccharide (LPS). The aim is to characterize two models of EIU through two routes of administration with novel noninvasive imaging techniques. 29 rats underwent Intraocular Pressure (IOP) measurements, Optical Coherence Tomography (OCT), proteomic analysis, and Positron Emission Tomography and Computed Tomography (PET/CT). Groups included healthy controls (C), BSS administered controls (Ci), systemically induced EIU with LPS (LPSs), and intravitreally induced EIU with LPS (LPSi) for IOP, OCT, and proteomic studies. For 18 F-FDG PET/CT study, animals were divided into FDG-C, FDG-LPSs and FDG-LPSi groups and scanned using a preclinical PET/CT system. LPSi animals exhibited higher IOP post-induction compared to C and LPSs groups. LPSi showed increased cellular infiltrate, fibrotic membranes, and iris inflammation. Proinflammatory proteins were more expressed in EIU models, especially LPSi. PET/CT indicated higher eye uptake in induced models compared to FDG-C. FDG-LPSi showed higher eye uptake than FDG-LPSs but systemic uptake was higher in FDG-LPSs due to generalized inflammation. OCT is valuable for anterior segment assessment in experimental models. 18 F-FDG PET/CT shows promise as a noninvasive biomarker for ocular inflammatory diseases. Intravitreal induction leads to higher ocular inflammation. These findings offer insights for future inflammatory disease research and drug studies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Chimeric antigen receptor (CAR) T-cell therapy has attracted considerable attention since its recent endorsement by the Food and Drug Administration, as it has emerged as a promising immunotherapeutic modality within the landscape of oncology. This study explores the prognostic utility of [ 18 F]Fluorodeoxyglucose positron emission tomography ([ 18 F]FDG PET) in lymphoma patients undergoing CAR T-cell therapy. Through meta-analysis, pooled hazard ratio (HR) values were calculated for specific PET metrics in this context., Methods: PubMed, Scopus, and Ovid databases were explored to search for relevant topics. Dataset retrieval from inception until March 12, 2024, was carried out. The primary endpoints were impact of specific PET metrics on overall survival (OS) and progression-free survival (PFS) before and after treatment. Data from the studies were extracted for a meta-analysis using Stata 17.0., Results: Out of 27 studies identified for systematic review, 15 met the criteria for meta-analysis. Baseline OS analysis showed that total metabolic tumor volume (TMTV) had the highest HR of 2.66 (95% CI: 1.52-4.66), followed by Total-body total lesion glycolysis (TTLG) at 2.45 (95% CI: 0.98-6.08), and maximum standardized uptake values (SUVmax) at 1.30 (95% CI: 0.77-2.19). TMTV and TTLG were statistically significant ( p < 0.0001), whereas SUVmax was not ( p = 0.33). For PFS, TMTV again showed the highest HR at 2.65 (95% CI: 1.63-4.30), with TTLG at 2.35 (95% CI: 1.40-3.93), and SUVmax at 1.48 (95% CI: 1.08-2.04), all statistically significant ( p ≤ 0.01). The ΔSUVmax was a significant predictor for PFS with an HR of 2.05 (95% CI: 1.13-3.69, p = 0.015)., Conclusion: [ 18 F]FDG PET parameters are valuable prognostic tools for predicting outcome of lymphoma patients undergoing CAR T-cell therapy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Al-Ibraheem, Abdlkadir, Al-Adhami, Sathekge, Bom, Ma’koseh, Mansour, Abdel-Razeq, Al-Rabi, Estrada-Lobato, Al-Hussaini, Matalka, Abdel Rahman and Fanti.)

In addition to tumor imaging, advanced high-tech PET/CT imaging is increasingly used to elucidate the underlying causes of fever of unknown origin caused by various inflammatory processes, including pyelonephritis. Two clinical cases of whole-body PET/CT with 18F-FDG glucose, which allowed to visualize the molecular and cellular features of acute pyelonephritis as the cause of fever of unknown origin, are presented in the article. The scientifically based mechanisms of this process and the reliability of the results are discussed.

Background: Although positron emission tomography (PET) imaging is well established for its diagnostic role in cardiac sarcoidosis, less is known about the prognostic value of PET and its use in risk stratification for major adverse cardiac events (MACE)., Objectives: The goal of this study was to perform a systematic review and meta-analysis looking at the prognostic value of PET imaging in patients with cardiac sarcoidosis., Methods: Study investigators systematically searched EMBASE (Excerpta Medica dataBASE), MEDLINE, PubMed, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, CINAHL (Cumulative Index to Nursing and Allied Health Literature), ClinicalTrials.gov, and the European Union Clinical Trial Registry for cardiac sarcoidosis and PET imaging. The primary outcome of interest was MACE., Results: The search revealed 3,010 records, of which 55 studies were included. This represented 5,250 patients. Factors associated with MACE included the following: the combination of abnormal fluorodeoxyglucose (FDG) uptake and perfusion defect, which had an OR of 2.86 (95% CI: 1.74-4.71; P < 0.0001); abnormal perfusion or FDG uptake, which had an OR of 2.69 (95% CI: 1.67-4.33); abnormal FDG uptake, which had an OR of 2.61 (95% CI: 1.51-4.50); focal abnormal right ventricular uptake, which had an OR of 6.27 (95% CI: 3.19-12.32; P < 0.00001); and a lack of response to immunosuppression on serial PET, which had an OR of 8.43 (95% CI: 3.25-21.85; P < 0.0001). A QUIPS (Quality in Prognostic Studies) tool analysis found a low to moderate risk of bias, particularly given the small sample sizes in the individual studies., Conclusions: Multiple cardiac PET parameters provide risk stratification value in cardiac sarcoidosis. Focal right ventricular uptake and a lack of response to immunosuppressive therapy on serial PET imaging were particularly predictive of MACE., Competing Interests: Funding Support and Author Disclosures The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: The aims of our study were to evaluate whether point-of-care β-hydroxybutyrate (BHB) measurement can be used to identify patients with adequate cardiac glucose metabolism suppression for cardiac [ 18 F]-fluoro-2-deoxy-d-glucose-positron emission tomography with computerized tomography (FDG-PET/CT) and to develop a pretest probability calculator of myocardial suppression using other metabolic factors attainable before imaging., Methods and Results: We recruited 193 patients with any clinical indication for whole body [ 18 F]-FDG-PET/CT. BHB level was measured with a point-of-care device. Maximal myocardial standardized uptake value using lean body mass (SULmax) was measured from eight circular regions of interest with 1 cm circumference and background from left ventricular blood pool. Correlations SULmax and point-of-care measured BHB were analysed. The ability of BHB test to predict adequate suppression was evaluated with receiver operating characteristic analysis. Liver and spleen attenuation in computed tomography were measured to assess the presence of fatty liver. BHB level correlated with myocardial uptake and, using a cut-off value of 0.35 mmol/L to predict adequate myocardial suppression, we reached specificity of 90% and sensitivity of 56%. Other variables to predict adequate suppression were diabetes, obesity, ketogenic diet and fatty liver. Using information attainable before imaging, we created a pretest probability calculator of inadequate myocardial glucose metabolism suppression. The area under the curve for BHB test alone was 0.802 and was 0.857 for the pretest calculator (p = 0.319)., Conclusions: BHB level measured with a point-of-care device is useful in predicting adequate myocardial glucose metabolism suppression. More detailed assessment of other factors potentially contributing to cardiac metabolism is needed., (© 2024 The Authors. Clinical Physiology and Functional Imaging published by John Wiley & Sons Ltd on behalf of Scandinavian Society of Clinical Physiology and Nuclear Medicine.)

This study aimed to determine the optimal injection dose for non-human primate positron emission tomography (PET). We first used a monkey brain phantom with a volume of 80,000 mm 3 containing 250 MBq of [ 18 F]FDG. Next, we compared the radioactivity difference between the PET images and the actual radioactivity from the dose calibrator to determine the low-error range. We then evaluated the image quality using the NEMA-NU phantom. Finally, [ 18 F]FP-CIT PET images were obtained from two monkeys with middle and high doses. As a result, PET images with a middle injected dose generated reasonable image quality and showed a high signal-to-noise ratio in monkey brain PET with [ 18 F]FP-CIT. These results are expected to be actively applied in PET research using non-human primates., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose: This study aimed to evaluate the ability of 18 F-FDG PET/CT metabolic parameters to predict the histological response to neoadjuvant chemotherapy in patients with osteosarcoma and Ewing sarcoma., Patients and Methods: This systematic review and network meta-analysis adhered to the PRISMA-NMA and Cochrane guidelines. Electronic databases were searched from January 2008 to January 2024; this search was supplemented by snowballing methods. The risk of bias was evaluated with QUADAS-2, and evidence certainty was assessed using the GRADE approach. The prognostic value of 18 F-FDG PET/CT parameters, including pretreatment and posttreatment SUVs (SUV1, SUV2 and the SUV2/SUV1 ratio), metabolic tumor volume (MTV1, MTV2, ΔMTV), and total lesion glycolysis (TLG1, TLG2, ΔTLG), was examined., Results: The meta-analysis of 18 studies (714 patients) identified the ΔTLG, ΔMTV, and SUV ratio as superior predictors of histological response. The changes in metabolic activity, as indicated by these parameters, provided a robust indication of treatment effectiveness. Baseline parameters showed limited predictive value compared with posttreatment assessments. The study's robustness was confirmed through meta-regression, which revealed that the predictive value of the SUV2 and SUV ratio was consistent across various cutoff thresholds., Conclusions: 18 F-FDG PET/CT metabolic parameters, particularly those measuring changes posttherapy, are effective in predicting the histological response in patients with osteosarcoma and Ewing sarcoma. These findings underscore the potential of 18 F-FDG PET/CT in guiding early treatment decisions, thereby enhancing personalized therapeutic approaches., Competing Interests: Conflicts of interest and sources of funding: none declared. The authors did not receive support from any organization for the submitted work., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Aim: This study aimed to evaluate the relationship between secreted frizzled-related protein 5 (SFRP5) expression and fluorine 18-fluoro-deoxyglucose (18 F-FDG) uptake imaged with positron emission tomography/tomography (PET/CT) in patients with non-small cell lung cancer (NSCLC). In addition, we sought to elucidate the potential role and mechanism of action of SFRP5 in NSCLC. Materials and methods: The maximum standardized uptake value (SUVmax) of the lesions was calculated. SFRP5 expression was analyzed using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The correlation between SFRP5 expression and SUVmax was evaluated using Pearson's correlation analysis. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), flow cytometry, wound healing, and transwell assays were used to analyze cell viability, apoptosis, migration, and invasion, respectively. Results and conclusion: The results indicated that the SUVmax was higher in patients with NSCLC than that in healthy volunteers. Moreover, SFRP5 expression was lower in tissues from the four types of NSCLC than that in the adjacent normal tissues. SUVmax negatively correlated with SFRP5 expression in the four types of NSCLC. In addition, up-regulation of SFRP5 decreased the viability, migration, and invasion abilities, and increased apoptosis of NSCLC cells. Furthermore, SFRP5 inhibited the Wnt/β-catenin pathway in NSCLC cells. In conclusion, SFRP5 modulates the biological behaviors of NSCLC through Wnt/β-catenin pathway.

Objective: To evaluate whether the maximum standardized uptake value (SUVmax) from initial 18F-FDG PET/CT (fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography) scans could be a predictor of complete response and recurrence in patients with endometrial cancer who are undergoing fertility sparing management., Methods: We conducted a retrospective review of patients who were diagnosed with endometrial cancer through biopsy and chose to undergo fertility sparing management using progestin at the Asan Medical Center, from January 2011 to December 2020. Of these, 113 patients who had an 18-FDG-PET/CT scan before starting treatment were included in our study. We measured SUVmax and examined its correlation with complete response and time to progression after achieving complete response to progestin therapy., Results: Of 113 patients, 73 (64.6%) achieved a complete response through fertility sparing management. The receiver operating characteristic curve analysis revealed that the optimal cut-off value of SUVmax for predicting complete response was 6.2 (sensitivity 79.5%, specificity 57.5%, p=0.006). After analyzing recurrence in the 73 patients who achieved complete response, we found that patients with an SUVmax value >6.2 had a significantly shorter time to progression compared with those with a value <6.2. (p=0.04)., Conclusions: SUVmax values of PET-CT, along with other clinicopathological parameters, could be used to predict treatment response and recurrence risk in patients with stage I endometrial cancer undergoing fertility sparing management., Competing Interests: Competing interests: None declared., (© IGCS and ESGO 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Competing Interests: None.

Thoracic aortic graft infections are infrequent yet grave complications of cardiovascular surgery. Risk factors include prolonged operative time, postoperative wound infections, and patient-specific risk factors like diabetes or malnutrition (Van Hemelrijck et al., Vessel Plus 6:47, 2022). In postoperative vascular scenarios, it is critical to utilize cross-sectional imaging to detect the presence of a complication, followed by describing the morphology, extent, and ancillary features. FDG-PET/CT can help differentiate between expected postoperative changes and worrisome infection by metabolic activity (FDG uptake). We present an extensive case of ascending aortic graft infection in the setting of ongoing sternal osteomyelitis. CT and PET/CT reveal chronic sternal osteomyelitic changes spreading into the retrosternal soft tissues, and a large intraluminal thrombus in the ascending aortic graft. Small mobile strands propagate toward the right brachiocephalic origin, posing a significant stroke risk. PET/CT confirmed postoperative infection by demonstrating increased FDG uptake., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

This document on cardiovascular infection, including infective endocarditis, is the first in the American Society of Nuclear Cardiology Imaging Indications (ASNC I 2 ) series to assess the role of radionuclide imaging in the multimodality context for the evaluation of complex systemic diseases with multisocietal involvement including pertinent disciplines. A rigorous modified Delphi approach was used to determine consensus clinical indications, diagnostic criteria, and an algorithmic approach to diagnosis of cardiovascular infection including infective endocarditis. Cardiovascular infection incidence is increasing and is associated with high morbidity and mortality. Current strategies based on clinical criteria and an initial echocardiographic imaging approach are effective but often insufficient in complicated cardiovascular infection. Radionuclide imaging with fluorine-18 fluorodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (CT) and single photon emission computed tomography/CT leukocyte scintigraphy can enhance the evaluation of suspected cardiovascular infection by increasing diagnostic accuracy, identifying extracardiac involvement, and assessing cardiac implanted device pockets, leads, and all portions of ventricular assist devices. This advanced imaging can aid in key medical and surgical considerations. Consensus diagnostic features include focal/multifocal or diffuse heterogenous intense 18 F-FDG uptake on valvular and prosthetic material, perivalvular areas, device pockets and leads, and ventricular assist device hardware persisting on non-attenuation corrected images. There are numerous clinical indications with a larger role in prosthetic valves, and cardiac devices particularly with possible infective endocarditis or in the setting of prior equivocal or non-diagnostic imaging. Illustrative cases incorporating these consensus recommendations provide additional clarification. Future research is necessary to refine application of these advanced imaging tools for surgical planning, to identify treatment response, and more., (Copyright © 2024 by the American Society of Nuclear Cardiology, the American College of Cardiology, Heart Rhythm Society, and the Infectious Diseases Society of America. Published by Elsevier on behalf of the American Society of Nuclear Cardiology, the American College of Cardiology, Heart Rhythm Society, and by Oxford University Press on behalf of the Infectious Diseases Society of America. Published by Elsevier Inc. All rights reserved.)

Response determined by 18[F]-fluoro-2-deoxy-D-glucose ( 18 F-FDG) positron emission tomography (PET)-CT after induction therapy can predict progression-free survival (PFS) in follicular lymphoma (FL). However, little prospective research has examined the significance of PET after second-line therapy. We conducted a prospective multicenter phase II trial (W-JHS NHL01) of bendamustine plus rituximab (BR) without rituximab maintenance for FL in first relapse. This study aimed to evaluate the usefulness of end-of-treatment (EOT)-PET for predicting PFS in FL patients in first relapse. EOT-PET examinations were performed between 6 and 8 weeks from the start of the last BR cycle. The primary endpoint was 1-year PFS. Key secondary endpoints were overall response rate (ORR), complete response rate (CRR), and 1-year overall survival (OS). Seventy-five patients were enrolled, and 8 were excluded from analysis. ORR was 86.6% and CRR was 59.7%. One-year PFS was 88.9% (95% confidence interval [CI] 80.7-94.3%) and 1-year OS in 75 patients was 97.3% (95% CI 89.6-99.3%). One-year PFS was significantly inferior in EOT-PET-positive patients (n = 9) compared with PET-negative patients (n = 58) (77.8% vs. 93.1%; p = 0.02). We confirmed that EOT-PET after second-line BR therapy could predict early progression in FL patients in first relapse., (© 2024. Japanese Society of Hematology.)

Purpose: Immunologic response to anti-programmed cell death protein 1 (PD-1) therapy can occur rapidly with T-cell responses detectable in as little as one week. Given that activated immune cells are FDG avid, we hypothesized that an early FDG PET/CT obtained approximately 1 week after starting pembrolizumab could be used to visualize a metabolic flare (MF), with increased tumor FDG activity due to infiltration by activated immune cells, or a metabolic response (MR), due to tumor cell death, that would predict response., Patients and Methods: Nineteen patients with advanced melanoma scheduled to receive pembrolizumab were prospectively enrolled. FDG PET/CT imaging was performed at baseline and approximately 1 week after starting treatment. FDG PET/CT scans were evaluated for changes in maximum standardized uptake value (SUVmax) and thresholds were identified by ROC analysis; MF was defined as >70% increase in tumor SUVmax, and MR as >30% decrease in tumor SUVmax., Results: An MF or MR was identified in 6 of 11 (55%) responders and 0 of 8 (0%) nonresponders, with an objective response rate (ORR) of 100% in the MF-MR group and an ORR of 38% in the stable metabolism (SM) group. An MF or MR was associated with T-cell reinvigoration in the peripheral blood and immune infiltration in the tumor. Overall survival at 3 years was 83% in the MF-MR group and 62% in the SM group. Median progression-free survival (PFS) was >38 months (median not reached) in the MF-MR group and 2.8 months (95% confidence interval, 0.3-5.2) in the SM group (P = 0.017)., Conclusions: Early FDG PET/CT can identify metabolic changes in melanoma metastases that are potentially predictive of response to pembrolizumab and significantly correlated with PFS., (©2024 American Association for Cancer Research.)

Objectives: To create a nomogram using single photon emission computed tomography (SPECT) myocardial perfusion imaging and 18 F-FDG positron emissions tomography (PET) gated myocardial metabolism imaging to forecast major adverse cardiovascular events (MACE) in chronic total occlusion (CTO) patients treated with optimal medical therapy (OMT). Methods: A total of 257 patients who received OMT between January 2016 and December 2021 were included in this retrospective study. Patients were randomly divided into development (n=179) and validation (n=78) cohorts. A thorough evaluation was conducted, encompassing clinical features and imaging analysis, which involved assessing myocardial perfusion and metabolism. Independent risk factors were identified using least absolute shrinkage and selection operator (LASSO) and multivariate Cox regression analyses. Calibration curves and decision curve analysis (DCA) were used to evaluate the clinical usefulness. Results: In the development cohort, 53 patients (29.6%) experienced MACE out of 179 patients, while in the validation cohort, MACE occurred in 23 (29.5%) patients out of 78. The PET-left ventricular end-systolic volume (P-ESV) (HR 1.01; 95% CI 1.003-1.017; p=0.003), hibernating myocardium / total perfusion defect (HM/TPD) (HR 1.053; 95% CI 1.038-1.069; p<0.001), PET-left ventricular ejection fraction (P-LVEF) (HR 0.862; 95% CI 0.788-0.943; p=0.001), and left anterior descending branch (LAD) (HR 2.303; 95% CI 1.086-4.884; p=0.03) were significantly associated with MACE and were used to develop the nomogram. The nomogram demonstrated excellent discrimination with C-indexes of 0.931 and 0.911 in the development and validation cohorts. DCA determined that the model exhibited a considerably superior net advantage in predicting MACE. Conclusion: A new nomogram integrating clinical factors and imaging features was created to predict the risk of MACE in patients with CTO., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Purpose: Study aims to investigate the consistency of delayed enhancement cardiac magnetic resonance imaging (DE-CMR) and 18 F-FDG PET myocardial imaging in evaluating myocardial viability before CABG., Methods: The study analyzed data from 100 patients who were examined with DE-CMR, PET imaging, and echocardiography before and after CABG. All subjects were followed up for 6-12 month post- CABG., Results: DE-CMR and PET imaging have high consistency (90.1%; Kappa value = 0.71, p < 0.01) in determining myocardial viability. The degree of delayed enhancement was negatively correlated with the improvement in myocardial contractile function in this segment after revascularization (P < 0.001). The ratio of scarred myocardial segments and total DE score was significantly lower in the improvement group than non-improvement group. Multivariate regression identified that hibernating myocardium (OR = 1.229, 95%CI: 1.053-1.433, p = 0.009) was influencing factor of LVEF improvement after CABG., Conclusion: Both imaging techniques are consistent in evaluating myocardial viability. Detecting the number of hibernating myocardium by PET is also important to predict the left heart function improvement after CABG., (© 2024. The Author(s).)

Objectives: In the present retrospective multicentric study, we combined [ 68 Ga]-DOTA-peptides and [ 18 F]FDG-PET/CT findings aiming to investigate their capability to differentiate typical (TC) and atypical pulmonary carcinoids (AC) and their prognostic role., Methods: From three centers, 61 patients were retrospectively included. Based on a dual tracer combination we classified PET scans as score 1, [ 18 F]FDG- and [ 68 Ga]-DOTA-peptides negative; score 2, [68Ga]-DOTA-peptides positive and [ 18 F]FDG-negative; score 3, [ 68 Ga]-DOTA-peptides negative and [ 18 F]FDG-positive; score 4, both tracers positive. Moreover, for each patient, the ratios of SUVmax on [ 68 Ga]-DOTA-PET to that on [ 18 F]FDG-PET were calculated (SUVr)., Results: Thirty-five patients had a final diagnosis of TC. Twenty-two TC (57%) had positive [ 68 Ga]-DOTA-peptides PET; instead, 21/26 (81%) AC had positive [ 18 F]FDG-PET/CT. On dual-tracer analysis, scores 1, 2, 3 and 4 were 13%, 20%, 43% and 24% for all populations; 17%, 26%, 20% and 37% for TC; 8%, 11%, 73% and 8% for AC. Median SUVr was significantly higher in TC than AC (6.4 vs. 0.4, p = 0.011). The best value of SUVr to predict the final diagnosis was 1.05 (AUC 0.889). Relapse or progression of disease happened in 17 patients (11 affected by AC) and death in 10 cases (7 AC). AC diagnosis, positive [ 18 F]FDG-PET, negative DOTA-PET and dual tracer score were significantly correlated with PFS (p = 0.013, p = 0.033, p = 0.029 and p = 0.019), while only AC diagnosis with OS (p = 0.022)., Conclusion: PET/CT findings had also a prognostic role in predicting PFS. Dual-tracer PET behavior may be used to predict the nature of pulmonary carcinoids and select the most appropriate management., Key Points: • Combination of [18F]FDG and [68Ga]-DOTA-peptides PET/CT results may help to differentiate between atypical and typical lung carcinoids. • The SUVmax ratio between [18F]FDG and [68Ga]-DOTA-peptides PET may help to differentiate between atypical and typical lung carcinoids. • Histotype and PET/CT features have a prognostic impact on PFS., (© 2022. The Author(s), under exclusive licence to European Society of Radiology.)

Abstract: It is well-known that physiological FDG uptake in the skeletal muscles is affected by serum insulin levels and the extent to which the muscles contract before the examination. Patients are instructed to refrain from strenuous exercise, talking too much, and taking meals at least 4 hours before the administration of the tracer. Even if the patient does not intend to exercise, muscular accumulation related to specific behaviors can still be visualized in the images. In this manuscript, we present FDG PET/CT images from 4 cases reflecting the mode of transportation used by the patients to visit the hospital., Competing Interests: Conflicts of interest and sources of funding: This manuscript was partly supported by the Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science only for the cost for English proofreading. The authors state that this work has not received any other funding, and there are no other conflicts of interest to disclose., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Although women and men are equally likely to receive ketamine following traumatic injury, little is known regarding sex-related differences in the impact of ketamine on traumatic memory. We previously reported that subanesthetic doses of an intravenous (IV) ketamine infusion following fear conditioning impaired fear extinction and altered regional brain glucose metabolism (BGluM) in male rats. Here, we investigated the effects of IV ketamine infusion on fear memory, stress hormone levels, and BGluM in female rats. Adult female Sprague-Dawley rats received a single IV ketamine infusion (0, 2, 10, or 20 mg/kg, over a 2-h period) following auditory fear conditioning (three pairings of tone and footshock). Levels of plasma stress hormones, corticosterone (CORT) and progesterone, were measured after the ketamine infusion. Two days after ketamine infusion, fear memory retrieval, extinction, and renewal were tested over a three-day period. The effects of IV ketamine infusion on BGluM were determined using 18 F-fluoro-deoxyglucose positron emission tomography ( 18 F-FDG-PET) and computed tomography (CT). The 2 and 10 mg/kg ketamine infusions reduced locomotor activity, while 20 mg/kg infusion produced reduction (first hour) followed by stimulation (second hour) of activity. The 10 and 20 mg/kg ketamine infusions significantly elevated plasma CORT and progesterone levels. All three doses enhanced fear memory retrieval, impaired fear extinction, and enhanced cued fear renewal in female rats. Ketamine infusion produced dose-dependent effects on BGluM in fear- and stress-sensitive brain regions of female rats. The current findings indicate that subanesthetic doses of IV ketamine produce robust effects on the hypothalamic-pituitary-adrenal (HPA) axis and brain energy utilization that may contribute to enhanced fear memory observed in female rats.

The classification according to uptake patterns and metabolic parameters on ring-type dedicated breast positron emission tomography (dbPET) is useful for detecting breast cancer. This study investigated the performance of dbPET for incidental findings that were not detected by mammography and ultrasonography. In 1,076 patients with breast cancer who underwent dbPET, 276 findings were incidentally diagnosed before treatment. Each finding was categorized as focus (uptake size ≤ 5 mm), mass (> 5 mm), or non-mass (multiple uptake) according to uptake patterns. Non-mass uptakes were additionally classified based on their distributions as-linear, focal, segmental, regional, or diffuse. Thirty-two findings (11.6%) were malignant and 244 (88.4%) were benign. Visually, 227 (82.3%) findings were foci, 7 (2.5%) were masses, and 42 (15.2%) were non-masses. Malignant rates of focus, mass, and non-mass were 9.7%, 28.6%, and 19.0%, respectively. In the non-mass findings, 23 were regional and diffuse distributions, and presented as benign lesions. Focus uptake with low lesion-to-background ratio (LBR) and no hereditary risk were relatively low (2.7%) in breast cancer. In multivariate analysis, LBR and hereditary risk were significantly associated with breast cancer (p = 0.006 and p = 0.013, respectively). Uptake patterns, LBR, and hereditary risk are useful for predicting breast cancer risk in incidental dbPET findings., (© 2022. The Author(s).)

An early and persistent sign of Alzheimer's disease (AD) is glucose hypometabolism, which can be evaluated by positron emission tomography (PET) with 18 F-2-fluoro-2-deoxy-D-glucose ([ 18 F]FDG). Cannabidiol has demonstrated neuroprotective and anti-inflammatory properties but has not been evaluated by PET imaging in an AD model. Intracerebroventricular (icv) injection of streptozotocin (STZ) is a validated model for hypometabolism observed in AD. This proof-of-concept study evaluated the effect of cannabidiol treatment in the brain glucose metabolism of an icv-STZ AD model by PET imaging. Wistar male rats received 3 mg/kg of STZ and [ 18 F]FDG PET images were acquired before and 7 days after STZ injection. Animals were treated with intraperitoneal cannabidiol (20 mg/kg-STZ-cannabidiol) or saline (STZ-saline) for one week. Novel object recognition was performed to evaluate short-term and long-term memory. [ 18 F]FDG uptake in the whole brain was significantly lower in the STZ-saline group. Voxel-based analysis revealed a hypometabolism cluster close to the lateral ventricle, which was smaller in STZ-cannabidiol animals. The brain regions with more evident hypometabolism were the striatum, motor cortex, hippocampus, and thalamus, which was not observed in STZ-cannabidiol animals. In addition, STZ-cannabidiol animals revealed no changes in memory index. Thus, this study suggests that cannabidiol could be an early treatment for the neurodegenerative process observed in AD.

Harnessing the power and flexibility of radiolabeled molecules, Cerenkov luminescence tomography (CLT) provides a novel technique for non-invasive visualisation and quantification of viable tumour cells in a living organism. However, owing to the photon scattering effect and the ill-posed inverse problem, CLT still suffers from insufficient spatial resolution and shape recovery in various preclinical applications. In this study, we proposed a total variation constrained graph manifold learning (TV-GML) strategy for achieving accurate spatial location, dual-source resolution, and tumour morphology. TV-GML integrates the isotropic total variation term and dynamic graph Laplacian constraint to make a trade-off between edge preservation and piecewise smooth region reconstruction. Meanwhile, the tetrahedral mesh-Cartesian grid pair method based on the k-nearest neighbour, and the adaptive and composite Barzilai-Borwein method, were proposed to ensure global super linear convergence of the solution of TV-GML. The comparison results of both simulation experiments and in vivo experiments further indicated that TV-GML achieved superior reconstruction performance in terms of location accuracy, dual-source resolution, shape recovery capability, robustness, and in vivo practicability. Significance: We believe that this novel method will be beneficial to the application of CLT for quantitative analysis and morphological observation of various preclinical applications and facilitate the development of the theory of solving inverse problem.

We evaluated the predictive value of 18 F-fluorodeoxyglucose (FDG) uptake on positron emission tomography/CT (PET/CT) for extended pathological T (pT) stages (≥ pT3a) in Renal cell carcinoma (RCC) patients at staging. Thirty-eight RCC patients who underwent 18 F-FDG PET/CT at staging, followed by radical nephrectomy between September 2016 and September 2018, were included in this prospective study. Patients were classified into two groups (limited pT stage: stage T1/2, n = 17; extended pT stage: T3/4, n = 21). Univariate and multivariate logistic regression analyses were performed to identify clinicopathological and metabolic variables to predict extended pT stages. 18 F-FDG metabolic parameters were compared in relation to International Society of Urological Pathology (ISUP) grade and lymphovascular invasion (LVI). In univariate analysis, maximum standardised uptake value, metabolic tumour volume (MTV), and ISUP grade were significant. In multivariate analysis, MTV was the only significant factor of extended pT stages. With a cut-off MTV of 21.2, an area under the curve was 0.944, which was higher than 0.824 for clinical T stages (p = 0.037). In addition, high MTV, but not tumour size, was significantly correlated with aggressive pathologic features (ISUP grade and LVI). High glycolytic tumour volume on 18 F-FDG PET/CT in RCC patients at staging is predictive of extended pT stages which could aid decision-making regarding the best type of surgery., (© 2021. The Author(s).)

Objectives/hypothesis: To assess the accuracy and utility of positron emission tomography/computed tomography (PET/CT) compared with magnetic resonance imaging (MRI) for detecting head and neck cancer (HNC) recurrence after microvascular reconstructive surgery., Study Design: Retrospective cohort study., Methods: Analysis of HNC patients who underwent microvascular reconstruction at a single, tertiary academic center following ablative surgery from 1998 to 2015. Forty-six patients aged 61.4 ± 15.8 years with both PET/CT and MRI examinations were identified. Two radiologists were blinded and interpreted each imaging study. Recurrence certainty scores were determined via continuous (0-100) and Likert ("Likely" to "Unlikely") scales, with larger values indicating a higher likelihood of recurrence. Pathologic confirmation of recurrence was confirmed in 23 patients (50%)., Results: Among those with primary site recurrences, mean recurrence certainty was significantly higher with PET/CT versus MRI on the continuous scale (63.9 vs. 44.4, P = .006). A receiver operating characteristic analysis for predicting primary site recurrence demonstrated a significantly larger area under the curve of 0.79 for PET/CT compared to 0.64 for MRI (P = .044). Categorization of "Likely" primary site recurrence on PET/CT, versus MRI, had higher sensitivity (0.63 vs. 0.40), but lower specificity (0.90 vs. 1.0). MRI demonstrated higher sensitivity (1.0 vs. 0.78) at detecting regional site recurrences., Conclusion: PET/CT demonstrates greater sensitivity than MRI as a surveillance tool for primary site recurrence following microvascular reconstruction where clinical evaluation is hindered by anatomical distortion. Therefore, PET/CT should be pursued as first-line imaging, with MRI utilized for confirmation of positive imaging findings at the primary site., Level of Evidence: 2 Laryngoscope, 131:2713-2718, 2021., (© 2021 The American Laryngological, Rhinological and Otological Society, Inc.)

Purpose of Review: Functional imaging with 18FDG-PET-CT has transformed the staging and response assessment of patients with Hodgkin (HL) and non-Hodgkin lymphoma (NHL). Herein, we review the current role and future directions for functional imaging in the management of patients with lymphoma., Recent Findings: Because of its increased sensitivity, PET-CT is the preferred modality for staging of FDG-avid lymphomas. It appears to have a role for interim assessment in patients with HL with adaptive strategies that reduce toxicity in lower risk patients and increase efficacy in those at high risk. Such a role has yet to be demonstrated in other histologies. FDG-PET-CT is also the gold standard for response assessment posttreatment. Newer uses include assessment of total metabolic tumor volume and radiomics in pretreatment prognosis. Whereas PET-CT is more sensitive than other current modalities for staging and response assessment, the future of PET-CT will be in conjunction with other modalities, notably assessment of minimal residual disease and microenvironmental markers to develop risk adaptive strategies to improve the outcome of patients with lymphoma., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: Recently, the national diagnostic reference levels (DRLs) in Japan were revised as the DRLs 2020, wherein the body weight-based injection dose optimization in positron emission tomography/computed tomography using 18 F-fluoro-2-deoxy-D-glucose ( 18 F-FDG PET/CT) was first proposed. We retrospectively investigated the usefulness of this optimization method in improving image quality and reducing radiation dose., Methods: A total of 1,231 patients were enrolled in this study. A fixed injection dose of 240 MBq was administered to 624 patients, and a dose adjusted to 3.7 MBq/kg body weight was given to 607 patients. The patients with body weight-based injection doses were further divided according to body weight: group 1 (≤ 49 kg), group 2 (50-59 kg), group 3 (60-69 kg), and group 4 (≥ 70 kg). The effective radiation dose of FDG PET was calculated using the conversion factor of 0.019 mSv/MBq, per the International Commission on Radiological Protection publication 106. Image quality was assessed using noise equivalent count density (NEC density ), which was calculated by excluding the counts of the brain and bladder. The usefulness of the injection dose optimization in terms of radiation dose and image quality was analyzed., Results: The body weight-based injection dose optimization significantly decreased the effective dose by 11%, from 4.54 ± 0.1 mSv to 4.05 ± 0.8 mSv (p < 0.001). Image quality evaluated by NEC density was also significantly improved by 10%, from 0.39 ± 0.1 to 0.43 ± 0.2 (p < 0.001). In no case did NEC density deteriorate when the effective dose was decreased. In group 1, the dose decreased by 32%, while there was no significant deterioration in NEC density (p = 0.054). In group 2, the dose decreased by 17%, and the NEC density increased significantly (p < 0.01). In group 3, the dose decreased by 3%, and the NEC density increased significantly (p < 0.01). In group 4, the dose increased by 14%, but there was no significant change in the NEC density (p = 0.766)., Conclusion: Body weight-based FDG injection dose optimization contributed to not only the reduction of effective dose but also the improvement of image quality in patients weighing between 50 and 69 kg., (© 2021. The Author(s).)

Purpose: To determine the impact of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) on clinical management in patients with suspected mycotic aortic aneurysms (MAA)., Materials and Methods: For this observational cohort study 101 PET/CT were acquired in 50 patients, thereof 50 for the initial diagnosis/baseline scan, 51 for follow-up. Impact on patient management was defined in three categories: PET/CT results were "confirmed" (by clinical follow-up), "suspected" (conclusive, not confirmed), or "misleading" (proven wrong by follow-up). For clinical follow-up patient data were recorded at the time of imaging, and at the latest recorded clinical visit. It included patient demographics, clinical information, laboratory data, results of microbiology and other diagnostic procedures, information about treatment, and patient's general health condition., Results: In four patients (8%) no clinical follow-up was feasible, the other 46 patients were clinically followed for a median of 898 days (IQR 320-4105). The combined evaluation of all 101 PET/CT demonstrated an impact on patient management in 78,5% of cases (48,5% confirmed, 30% suspected). Results of 21,5% of the PET/CT examinations were misleading. Respective values at baseline and at follow-up were: impact on patient management in 82% and 74,5% (70% and 27.5% confirmed, and 12% and 47% suspected), misleading cases in 18% and 25.5%., Conclusion: In MAA, PET/CT has a high impact on patient management, which is more pronounced with baseline than with follow-up examinations. However, PET/CT results may be misleading in a smaller proportion of cases., Competing Interests: The authors have declared that no competing interests exist.

Abstract: The purpose of the present study is to investigate whether the 18F-fluorodeoxyglucose (18F-FDG) uptake parameter is related to survival outcomes for patients with clinical T3-T4a laryngeal cancer with various definitive treatments including total laryngectomy (TL). Parameters of 18F-FDG uptake in the primary tumors of 46 cases which were assessed by positron emission tomography with computed tomography were enrolled in the present observation study. Monovariate or multivariate survival analyses were performed with log-rank test or Cox regression model, with the hazard ratio (HR) and 95% confidence interval (CI), respectively. Cutoff values of the 18F-FDG uptake parameters were determined by the lowest P-value for monovariate overall survival. In the monovariate analysis, both metabolic tumor volume ≥13.1 and total lesion glycolysis (TLG) ≥46.5 were significantly associated with shorter overall survival, and TLG ≥46.5 was also related to a reduction in distant metastasis-free survival. In the multivariate analysis adjusting for clinical T classification (cT4/cT3) and treatment group (TL/non-TL), TLG (≥46.5/<46.5) was associated with both poorer overall (HR: 3.16, 95% CI: 1.10-9.49) and distant metastasis-free (HR: 8.91, 95% CI: 1.93-62.6) survival. In conclusion, TLG is a predictor for survival in laryngeal cancer., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: To examine the prognostic significance of pretreatment 2-deoxy-2-[ 18 F]fluoro-D-glucose ([ 18 F]-FDG) positron emission tomography (PET)-based radiomic features using a machine learning approach in patients with endometrial cancers., Procedures: Included in this retrospective study were 53 patients with endometrial cancers who underwent [ 18 F]-FDG PET/X-ray computed tomography (CT) before treatment. Since two different PET scanners were used, post-reconstruction harmonization was performed for all PET parameters using the ComBat harmonization method. Four clinical (age, histological type, stage, and treatment method) and 40 [ 18 F]-FDG PET-based radiomic features were ranked, and a subset of useful features was selected based on the decrease in the Gini impurity in terms of associations with disease progression. The machine learning algorithms (random forest, neural network, k-nearest neighbors (kNN), naive Bayes, logistic regression, and support vector machine) were compared using the areas under the receiver operating characteristic curve (AUC) and validated by the random sampling method. Progression-free survival (PFS) and overall survival (OS) were assessed by the Cox regression analysis., Results: The five best predictors of disease progression were coarseness, gray-level run length nonuniformity, stage, treatment method, and gray-level zone length nonuniformity. The kNN model obtained the best performance classifier for predicting the disease progression (AUC =0.890, accuracy =0.849, F1 score =0.848, precision =0.857, and recall =0.849). Coarseness which was the first ranked radiomic feature was selected for survival analyses, and only coarseness remained as a significant and independent factor for both PFS (hazard ratios (HR), 0.65; 95 % confidence interval [CI], 0.49-0.86; p=0.003) and OS (HR, 0.52; 95 % CI, 0.36-0.76; p<0.001) at multivariate Cox regression analysis., Conclusions: [ 18 F]-FDG PET-based radiomic analysis using a machine learning approach may be useful for predicting tumor progression and prognosis in patients with endometrial cancers., (© 2021. World Molecular Imaging Society.)

Purpose: To investigate the possibility of reducing the injected activity for whole-body [18F]FDG-PET/CT studies of paediatric oncology patients and to assess the usefulness of time-of-flight (TOF) acquisition on PET image quality at reduced count levels., Procedures: Twenty-nine paediatric oncology patients (12F/17M, 3-18 years old (median age 13y), weight 45±20 kg, BMI 19±4 kg/m 2 ), who underwent routine whole-body PET/CT examinations on a Siemens Biograph mCT TrueV system with TOF capability (555ps) were included in this study. The mean injected activity was 156 ± 45 MBq (3.8 ± 0.8 kg/MBq) and scaled to patient weight. The raw data was collected in listmode (LM) format and pre-processed to simulate reduced levels of [18F]FDG activity (75, 50, 35, 20 and 10% of the original counts) by randomly removing events from the original LM data. All data were reconstructed using the vendor-specific e7-tools with standard OSEM only, with OSEM plus resolution recovery (PSF). The reconstructions were repeated with added TOF (TOF) and PSF+TOF. The benefit of TOF together with the reduced count levels was evaluated by calculating the gains in signal-to-noise ratio (SNR) in the liver and contrast-to-noise ratio (CNR) in all PET-positive lesions before and after TOF employed at every simulated reduced count level. Finally, the PSF+TOF images at 50, 75 and 100% of counts were evaluated clinically on a 5-point scale by three nuclear medicine physicians., Results: The visual inspection of the reconstructed images did not reveal significant differences in image quality between 75 and 100% count levels for PSF+TOF. The improvements in SNR and CNR were the greatest for TOF reconstruction and PSF combined. Both SNR and CNR gains did increase linearly with the patients BMI for both OSEM only and PSF reconstruction. These benefits were observed until reducing the counts to 50 and 35% for SNR and CNR, respectively., Conclusions: The benefit of using TOF was noticeable when using 50% or greater of the counts when evaluating the CNR and SNR. For [18F]FDG-PET/CT, whole-body paediatric imaging the injected activity can be reduced to 75% of the original dose without compromising PET image quality., (© 2021. The Author(s).)

Background & Aims: The connection between peripheral insulin resistance (IR) and coronary artery disease is well-established. Both are major risk factors for the development of ischemic cardiomyopathy potentially leading to heart failure (HF). Whether cardiac IR also impacts overall survival and morbidity is still debated. We therefore aimed to test if cardiac IR predicts mortality and major cardiovascular events (MACE) in patients with HF scheduled for cardiac viability testing before revascularization., Methods: This retrospective study included 131 patients with a clinical diagnosis of ischemic HF (114 (87%) male, 33 (25%) with diabetes) referred to a viability Rubidium-82 (perfusion) and dynamic 18 F-Fluorodeoxyglucose (metabolism) positron emission tomography combined with computed tomography prior to a potential revascularization procedure. Cardiac IR was assessed by myocardial glucose uptake (MGU) in a remote (non-scarred) area of the left ventricle during a hyperinsulinemic-euglycemic clamp (1mIE/kg/min)., Results: MGU correlated with skeletal muscle glucose uptake (p < 0.001) and whole-body glucose uptake (M-value) (p < 0.001), whereas no association was observed for individuals with diabetes. MGU did not predict the risk of death or MACE. However, both overt diabetes and reduced coronary flow reserve predicted overall survival., Conclusion: Even though diabetes and related small-vessel disease is associated with increased mortality, cardiac IR per se does not predict cardiovascular morbidity and mortality., Competing Interests: Declaration of competing interest All authors declare no conflict of interests., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: To determine the normal perivalvular 18 F-Fluorodeoxyglucose ( 18 F-FDG) uptake on positron emission tomography (PET) with computed tomography (CT) within one year after aortic prosthetic heart valve (PHV) implantation., Methods: Patients with uncomplicated aortic PHV implantation were prospectively included and underwent 18 F-FDG PET/CT at either 5 (± 1) weeks (group 1), 12 (± 2) weeks (group 2) or 52 (± 8) weeks (group 3) after implantation. 18 F-FDG uptake around the PHV was scored qualitatively (none/low/intermediate/high) and quantitatively by measuring the maximum Standardized Uptake Value (SUV max ) and target to background ratio (SUV ratio )., Results: In total, 37 patients (group 1: n = 12, group 2: n = 12, group 3: n = 13) (mean age 66 ± 8 years) were prospectively included. Perivalvular 18 F-FDG uptake was low (8/12 (67%)) and intermediate (4/12 (33%)) in group 1, low (7/12 (58%)) and intermediate (5/12 (42%)) in group 2, and low (8/13 (62%)) and intermediate (5/13 (38%)) in group 3 (P = 0.91). SUV max was 4.1 ± 0.7, 4.6 ± 0.9 and 3.8 ± 0.7 (mean ± SD, P = 0.08), and SUV ratio was 2.0 [1.9 to 2.2], 2.0 [1.8 to 2.6], and 1.9 [1.7 to 2.0] (median [IQR], P = 0.81) for groups 1, 2, and 3, respectively., Conclusion: Non-infected aortic PHV have similar low to intermediate perivalvular 18 F-FDG uptake with similar SUV max and SUV ratio at 5, 12, and 52 weeks after implantation., (© 2020. The Author(s).)

Over the past several decades, molecular imaging techniques to assess cellular processes in vivo have been integral in advancing our understanding of disease pathogenesis. 18 F-fluorodeoxyglucose (18-FDG) positron emission tomography (PET) imaging in particular has shaped the field of atherosclerosis research by highlighting the importance of underlying inflammatory processes that are responsible for driving disease progression. The ability to assess physiology using molecular imaging, combining it with anatomic delineation using cardiac coronary angiography (CCTA) and magnetic resonance imaging (MRI) and lab-based techniques, provides a powerful combination to advance both research and ultimately clinical care. In this review, we demonstrate how molecular imaging studies, specifically using 18-FDG PET, have revealed that early vascular disease is a systemic process with multiple, concurrent biological mechanisms using inflammatory diseases as a basis to understand early atherosclerotic mechanisms in humans., (© 2020. This is a U.S. government work and its text is not subject to copyright protection in the United States; however, its text may be subject to foreign copyright protection.)

Interim FDG-PET (iPET) in diffuse large B-cell lymphoma (DLBCL) is increasingly practised and used in clinical trials to adapt further therapy. However, the optimum timing and methodology of iPET remains controversial. We retrospectively analysed the iPET results and outcomes of 200 DLBCL patients where FDG-PET was routinely performed at baseline, after 2 cycles (iPET2) and at completion of chemoimmunotherapy. iPET was also performed after 4 cycles (iPET4) where at iPET2, Deauville score (DS) was ≥4. Scans were assessed by blinded expert lymphoma PET physicians for DS, maximum standard uptake value (SUVmax), total metabolic tumour volume (TMTV) and total lesion glycolysis (TLG). Treatment failure was defined as death, progression or refractory disease. 95.5% of patients received R-CHOP. No baseline PET parameter was predicted for EFS or OS independent of the NCCN-IPI. The multivariable analysis at iPET2 showed DS5 (19.5% of cases) predicted treatment failure (HR 6.29, 95% CI 3.01-13.17, P < .001), but DS4 was equivalent to DS1-3. At iPET4, ΔSUVmax < 66% predicted treatment failure (HR 5.49, 95% CI 3.03-9.99, P < .001). By multivariable analysis of all time points, high NCCN-IPI and DS5 at iPET2 were negative predictors of survival. These findings were independent of novel prognostic markers., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: 18 F-fluoromisonidazole (FMISO) is a hypoxia positron emission tomography (PET) tracer. Here, we evaluated cardiac and extra-cardiac sarcoidosis using both FMISO and 18 F-fluorodeoxyglucose (FDG) PET/CT in a prospective cohort of patients with sarcoidosis., Methods: Ten consecutive sarcoidosis patients with suspected cardiac involvement were prospectively enrolled. Each patient fasted overnight (for ≥ 18 hours) preceded by a low-carbohydrate diet before FDG PET/CT but not given special dietary instructions before the FMISO PET/CT scan. We visually and semiquantitatively assessed the uptakes of FMISO and FDG using the maximal standardized uptake value (SUV max ). The metabolic volume (MV) of FDG was calculated as the volume within the boundary determined by the threshold (mean SUV of blood pool × 1.5)., Results: Nine patients showed focal FDG uptake in the myocardium and were diagnosed with cardiac sarcoidosis. Among the patients with extra-cardiac lesions, FDG uptake was seen in 8 lymph nodes and 3 lung lesions. FMISO uptake was seen in the 7 cardiac (77.8%) and 6 extra-cardiac (54.5%) lesions. None of the patients showed physiological FMISO uptake in the myocardium. The SUV max values of the lesions with FMISO uptake were higher than those of the lesions without FMISO uptake in both the cardiac (SUV max : 9.9, IQR: 8.4-10.0 vs 7.3, IQR: 6.3-8.2) and non-cardiac lesions (SUV max : 17.6, IQR: 14.5-19.3 vs 6.1, IQR: 5.9-6.2; P = 0.006). The MV values of the lesions with FMISO uptake were significantly higher than those of the lesions without FMISO uptake (111.3, IQR: 78.3-135.7 vs 6.4, IQR: 1.9-23.3; P = 0.0009)., Conclusions: FMISO showed no physiological myocardial uptake and did not require special preparation. FMISO PET has the potential to detect hypoxic lesions in patients with sarcoidosis., (© 2019. American Society of Nuclear Cardiology.)

Purpose: The aim of this study was the evaluation of quantitative and qualitative parameters for the diagnosis of aortic graft infection (AGI) using [ 18 F]-FDG PET/CT., Methods: PET/CT was performed in 50 patients with clinically suspected AGI. 12 oncological patients with aortic repair but without suspicion of AGI were included in the analysis to serve as control cohort. The [ 18 F]-FDG uptake pattern around the graft was assessed using (a) a five-point visual grading scale (VGS), (b) SUV max and (c) different graft-to-background ratios (GBRs). The diagnostic performance of VGS, SUV max and GBRs was assessed and compared by ROC analysis., Results: 28 infected and 34 uninfected grafts were identified by standard of reference. SUV max and VGS were the most powerful predictors for the diagnosis of AGI according to the area under the curve (AUC 0.988 and 0.983, respectively) without a significant difference compared to GBRs. SUV max and VGS showed congruent and accurate findings in 54 patients (i.e. either both positive or negative), yielding sensitivity and specificity (100%) in this subgroup of patients., Conclusion: Quantitative analysis by SUV max and qualitative analysis by VGS are highly effective in the diagnosis of AGI and should be tested as an outcome measure in prospective trials., (© 2020. American Society of Nuclear Cardiology.)