Lateralized periodic discharges frequency correlates with glucose metabolism

ObjectiveTo investigate the correlation between characteristics of lateralized periodic discharges (LPDs) and glucose metabolism measured by 18F-fluorodeoxyglucose (FDG)–PET.MethodsWe retrospectively reviewed medical records to identify patients who underwent FDG-PET during EEG monitoring with LPDs present during the FDG uptake period. Two blinded board-certified neurophysiologists independently interpreted EEGs. FDG uptake was measured using standardized uptake value (SUV). Structural images were fused with PET images to aid with localization of SUV. Two PET readers independently measured maximum SUV. Relative SUV values were obtained by normalization of the maximum SUV to the SUV of pons (SUVRpons). LPD frequency was analyzed both as a categorical variable and as a continuous measure. Other secondary variables included duration, amplitude, presence of structural lesion, and “plus” EEG features such as rhythmic or fast sharp activity.ResultsNine patients were identified and 7 had a structural etiology for LPDs. Analysis using frequency as a categorical variable and continuous variable showed an association between increased LPD frequency and increased ipsilateral SUVRpons (p = 0.02). Metabolism associated with LPDs (0.5 Hz as a baseline) increased by a median of 100% at 1 Hz and for frequencies >1 Hz increased by a median of 309%. There were no statistically significant differences in SUVRpons for other factors including duration (p = 0.10), amplitude (p = 0.80), structural etiology (p = 0.55), or “plus” features such as rhythmic or fast sharp activity (p = 0.84).ConclusionsMetabolic activity increases monotonically with LPD frequency. LPD frequency should be a measure of interest when developing neuroprotection strategies in critical neurologic illness.

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Assessment of Brain Glucose Metabolism Following Cardiac Arrest by [18F]FDG Positron Emission Tomography

10.1101/2020.01.08.899252 ◽

2020 ◽

Author(s):

Hannah J. Zhang ◽

Samuel Mitchell ◽

Yong-Hu Fang ◽

Hsiu-Ming Tsai ◽

Lin Piao ◽

...

Keyword(s):

Cardiac Arrest ◽

Glucose Metabolism ◽

Fdg Pet ◽

Brain Metabolism ◽

Persistent Vegetative State ◽

Standardized Uptake Value ◽

Brain Atlas ◽

Fdg Uptake ◽

Pet Ct ◽

The Brain

AbstractBackgroundCardiac arrest (CA) patients who survived by cardiopulmonary resuscitation (CPR) can present different levels of neurological deficits ranging from minor cognitive impairments to persistent vegetative state and brain death. The pathophysiology of the resulting brain injury is poorly understood and whether changes in post-CA brain metabolism contribute to the injury are unknown. Here we utilized [18F]FDG-PET to study in vivo cerebral glucose metabolism 72 hours following CA in a murine cardiac arrest model.MethodsAnesthetized and ventilated adult C57BL/6 mice underwent 12-minute KCl-induced CA followed by CPR. Seventy-two hours following cardiac arrest, surviving mice were intraperitoneally injected with [18F]FDG (~186 μCi/200 μL) and imaged on Molecubes preclinical micro PET/CT imaging systems after a 30-minute awake uptake period. Brain [18F]FDG uptake was determined by the VivoQuant software on fused PET/CT images with the 3D brain atlas. Upon completion of PET imaging, remaining [18F]FDG radioactivity in the brain, heart, and liver was determined using a gamma counter.ResultsGlobal increases in brain [18F]FDG uptake in post-CA mice were observed compared to shams and controls. The median standardized uptake value (SUV) of [18F]FDG for CA animals was 1.79 vs. sham 1.25 (p<0.05) and control animals 0.78 (p<0.01). This increased uptake was consistent throughout the 60-minute imaging period and across all brain regions reaching statistical significance in the midbrain, pons, and medulla. Biodistribution analyses of various key organs yielded similar observations that the median [18F]FDG uptake for brain were 7.04%ID/g tissue for CA mice vs 5.537%ID/g tissue for sham animals, p<0.05).ConclusionsThis study has successfully applied [18F]FDG-PET/CT to measure changes in brain metabolism in a murine model of asystolic CA. Our results demonstrate increased [18F]FDG uptake in the brain 72 hours following CA, suggesting increased metabolic demand in the case of severe neurological injury. Further study is warranted to determine the etiology of these changes.

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Pulmonary Findings of [18F]FDG PET/CT Images on Asymptomatic COVID-19 Patients

Pathogens ◽

10.3390/pathogens10070839 ◽

2021 ◽

Vol 10 (7) ◽

pp. 839

Author(s):

Tzu-Chuan Ho ◽

Chin-Chuan Chang ◽

Hung-Pin Chan ◽

Ying-Fong Huang ◽

Yi-Ming Arthur Chen ◽

...

Keyword(s):

Systematic Review ◽

Fdg Pet ◽

Standardized Uptake Value ◽

Fdg Uptake ◽

Asymptomatic Patients ◽

Positron Emission ◽

Pet Ct ◽

18F Fdg ◽

Maximal Standardized Uptake Value ◽

Fdg Pet Ct

During the coronavirus disease 2019 (COVID-19) pandemic, several case studies demonstrated that many asymptomatic patients with COVID-19 underwent fluorine-18 fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) examination for various indications. However, there is a lack of literature to characterize the pattern of [18F]FDG PET/CT imaging on asymptomatic COVID-19 patients. Therefore, a systematic review to analyze the pulmonary findings of [18F]FDG PET/CT on asymptomatic COVID-19 patients was conducted. This systematic review was performed under the guidelines of PRISMA. PubMed, Medline, and Web of Science were used to search for articles for this review. Articles with the key words: “asymptomatic”, “COVID-19”, “[18F]FDG PET/CT”, and “nuclear medicine” were searched for from 1 January 2020 to 20 May 2021. Thirty asymptomatic patients with COVID-19 were included in the eighteen articles. These patients had a mean age of 62.25 ± 14.85 years (male: 67.71 ± 12.00; female: 56.79 ± 15.81). [18F]FDG-avid lung lesions were found in 93.33% (28/30) of total patients. The major lesion was [18F]FDG-avid multiple ground-glass opacities (GGOs) in the peripheral or subpleural region in bilateral lungs, followed by the consolidation. The intensity of [18F]FDG uptake in multiple GGOs was 5.605 ± 2.914 (range from 2 to 12) for maximal standardized uptake value (SUVmax). [18F]FDG-avid thoracic lymph nodes (LN) were observed in 40% (12/40) of the patients. They mostly appeared in both mediastinal and hilar regions with an SUVmax of 5.8 ± 2.93 (range from 2.5 to 9.6). The [18F]FDG uptake was observed in multiple GGOs, as well as in the mediastinal and hilar LNs. These are common patterns in PET/CT of asymptomatic patients with COVID-19.

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Coronary, aortic and carotid artery inflammation by 18F-fluorodeoxyglucose positron emission tomography in acute and chronic coronary artery disease

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jeaa356.344 ◽

2021 ◽

Vol 22 (Supplement_1) ◽

Author(s):

W Nammas ◽

S Uotila ◽

J Teuho ◽

M Pietila ◽

J Airaksinen ◽

...

Keyword(s):

Coronary Arteries ◽

Fdg Pet ◽

Carotid Arteries ◽

Standardized Uptake Value ◽

Chronic Coronary Artery Disease ◽

Fdg Uptake ◽

Positron Emission ◽

Arterial Inflammation ◽

18F Fdg ◽

Artery Disease

Abstract Funding Acknowledgements Type of funding sources: None. Background 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) can detect arterial inflammation in individuals with atherosclerosis, but the associations among different vascular territories for 18F-FDG uptake are not known. Purpose We explored any possible correlation between arterial inflammation quantified by 18F-FDG PET in the aorta, carotid arteries, and coronary arteries in patients presenting with acute coronary syndrome (ACS), or chronic coronary artery disease (CAD). Methods Prospectively, we performed hybrid computed tomography angiography and 18F-FDG PET in 43 patients (26 ACS and 17 chronic CAD) at 6.6 ± 5.7 days following invasive coronary angiography. 18F-FDG PET was performed 90 minutes after injection of 302.2 ± 28.4 MBq 18F-FDG. Arterial 18F-FDG uptake was measured in the thoracic aorta, carotid arteries, and coronary arteries, and expressed as the target-to-background ratio (TBR; the ratio between arterial maximal standardized uptake value normalized to blood pool mean standardized uptake value) in the whole artery, and in the most diseased segment (MDS). Results Mean age was 64.9 ± 9.1 years, 90.7% males. The whole artery 18F-FDG uptake was higher in the aorta than in the carotid arteries (median TBR 2.23, interquartile range [0.36] vs. 1.88 [0.42], p < 0.001); whereas uptake in the coronary arteries was lower than in the aorta or carotid arteries (1.13 [0.23], p < 0.001 both). Similarly, 18F-FDG uptake in the aortic MDS was higher than in the carotid MDS (2.75 [0.62] vs. 2.25 [0.63], p < 0.001); whereas 18F-FDG uptake in the coronary MDS was the lowest (1.40 [0.33], p < 0.001 both). These findings were consistent in both ACS and chronic CAD patients. The whole artery 18F-FDG uptake of the aorta and carotid arteries correlated in patients with ACS (r = 0.58, p = 0.002), but not in patients with chronic CAD (r = 0.21, p = 0.3). There was no correlation between the whole artery 18F-FDG uptake in the coronary arteries and either the aorta or carotid arteries in the whole cohort (r=-0.16, p = 0.2, r = 0.01, p = 0.9, respectively), in patients with ACS (r = 0.06, p = 0.7, r=-0.01, p = 0.9, respectively), or in those with chronic CAD (r=-0.4, p = 0.1, r=-0.09, p = 0.7, respectively). Conclusions In patients with ACS or chronic CAD, large arteries had higher 18F-FDG uptake than the coronary arteries. The intensity of 18F-FDG uptake in the coronary arteries did not correlate with that in the carotid arteries or the aorta, indicating that disease activity differs between large arteries and coronary arteries.

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Thyroid lesions incidentally detected by 18F-FDG PET-CT ― a two centre retrospective study

Radiology and Oncology ◽

10.2478/raon-2014-0039 ◽

2015 ◽

Vol 49 (2) ◽

pp. 121-127 ◽

Cited By ~ 10

Author(s):

Jan Jamsek ◽

Ivana Zagar ◽

Simona Gaberscek ◽

Marko Grmek

Keyword(s):

Fdg Pet ◽

Malignant Lesion ◽

Standardized Uptake Value ◽

Benign Lesions ◽

Fdg Uptake ◽

Pet Ct ◽

Thyroid Uptake ◽

Malignant Lesions ◽

Fdg Pet Ct ◽

Thyroid Lesions

AbstractBackground. Incidental18F-FDG uptake in the thyroid on PET-CT examinations represents a diagnostic challenge. The maximal standardized uptake value (SUVmax) is one possible parameter that can help in distinguishing between benign and malignant thyroid PET lesions.Patients and methods. We retrospectively evaluated18F-FDG PET-CT examinations of 5,911 patients performed at two different medical centres from 2010 to 2011. If pathologically increased activity was accidentally detected in the thyroid, the SUVmaxof the thyroid lesion was calculated. Patients with incidental18F-FDG uptake in the thyroid were instructed to visit a thyroidologist, who performed further investigation including fine needle aspiration cytology (FNAC) if needed. Lesions deemed suspicious after FNAC were referred for surgery.Results. Incidental18F-FDG uptake in the thyroid was found in 3.89% ― in 230 out of 5,911 patients investigated on PET-CT. Malignant thyroid lesions (represented with focal thyroid uptake) were detected in 10 of 66 patients (in 15.2%). In the first medical centre the SUVmaxof 36 benign lesions was 5.6 ± 2.8 compared to 15.8 ± 9.2 of 5 malignant lesions (p < 0.001). In the second centre the SUVmaxof 20 benign lesions was 3.7 ± 2.2 compared to 5.1 ± 2.3 of 5 malignant lesions (p = 0.217). All 29 further investigated diffuse thyroid lesions were benign.Conclusions. Incidental18F-FDG uptake in the thyroid was found in 3.89% of patients who had a PET-CT examination. Only focal thyroid uptake represented a malignant lesion in our study ― in 15.2% of all focal thyroid lesions. SUVmaxshould only serve as one of several parameters that alert the clinician on the possibility of thyroid malignancy.

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Use of 68Ga-PSMA-11 and 18F-FDG PET-CT Dual-Tracer to Differentiate Between Lymph Node Metastases and Ganglia

Frontiers in Oncology ◽

10.3389/fonc.2021.646110 ◽

2021 ◽

Vol 11 ◽

Author(s):

Yiping Shi ◽

Lian Xu ◽

Yinjie Zhu ◽

Yining Wang ◽

Ruohua Chen ◽

...

Keyword(s):

Lymph Node ◽

Lymph Node Metastases ◽

Fdg Pet ◽

Standardized Uptake Value ◽

Fdg Uptake ◽

Positron Emission ◽

Pet Ct ◽

Node Metastases ◽

Ct Data ◽

Fdg Pet Ct

PurposeDifferentiating lymph node metastases (LNM) from peripheral ganglia by physiological prostate-specific membrane antigen (PSMA) uptake is challenging. Two tracers (68Ga-PSMA-11 and 18F-fluorodeoxyglucose [FDG]) metabolic uptake patterns were evaluated by positron emission tomography-computed tomography (PET-CT), searching for differences that could tell ganglia from LNM.MethodsDual 68Ga-PSMA-11 and 18F-FDG PET-CT data of 138 prostate cancer patients acquired from June 2018 to December 2019 were retrospectively evaluated. Ganglia and LNM with PSMA-11 uptake above local background were analyzed by the location and PSMA-11-PET and FDG-PET maximum standardized uptake value (SUVmax).ResultsPSMA-11-positive ganglia (n = 381) and LNM (n = 83) were identified in 138 and 58 patients, respectively. The LNM SUVmax of PSMA-11-PET (16.4 ± 14.8 vs 2.3 ± 0.7, P < 0.001) and FDG-PET (3.3 ± 3.2 vs 1.5 ± 0.5, P < 0.001) were higher than in ganglia. The probabilities of being an LNM in the low-potential (PSMA-11-PET SUVmax of <4.1 and FDG-PET SUVmax of <2.05), moderate-potential (PSMA-11-PET SUVmax of >4.1 and FDG-PET SUVmax of <2.05, or PSMA-11-PET SUVmax of <4.1 and FDG-PET SUVmax of >2.05), and high-potential (PSMA-11-PET SUVmax of >4.1 and FDG-PET SUVmax of >2.05) groups were 0.9% (3/334), 44.6% (37/83), and 91.5% (43/47), respectively (P < 0.001). The cervical and coeliac ganglia had higher PSMA-11 and FDG uptake than the sacral ganglia (P < 0.001 for all). LNM PSMA-11 and FDG uptake was similar in these three locations.ConclusionThe FDG-PET and PSMA-11-PET SUVmax, especially when combined, could well differentiate LNM from ganglia. The tracers uptake differed between cervical/coeliac and sacral ganglia, so the lesion location should be considered during image assessment.

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PET is only moderately informative regarding theranostic Ttarget HIF-1α expression in solid tumors: A meta-analysis

10.21203/rs.2.17589/v1 ◽

2019 ◽

Author(s):

Alexey Surov ◽

Stefan A. Schmidt ◽

Vikas Prasad ◽

Ambros J. Beer ◽

Andreas Wienke

Keyword(s):

Solid Tumors ◽

Tumor Cells ◽

Fdg Pet ◽

Standardized Uptake Value ◽

Correlation Coefficients ◽

Hexokinase 2 ◽

Primary Tumors ◽

Glut 1 ◽

Fdg Uptake ◽

Specific Tumor

Abstract BACKGROUND: Hypoxia-inducible factor (HIF)-1α plays a key role in hypoxic adaptation of tumor cells. HIF-1α is overexpressed in solid tumor, directs the glucose metabolism pathway from oxidative to anaerobic pathway thereby reducing the oxygen consumption, decreases free radical level and thence prevents cancer cell death. 2-deoxy-2 [18F] fluoro-D-glucose (FDG) is taken up in solid tumors primarily regulated through glucose transporter 1 (GLUT-1) and hexokinase 2 which in turn are regulated by HIF-1α. Positron Emission Tomography (PET) with FDG allows semiquantitative delineation of GLUT-1 and Hexokinase 2 activity in tumor cells by standardized uptake value (SUV). There are inconsistent data about relationships between FDG-PET and HIF-1a. The purpose of the present analysis was to provide evidence regarding associations between FDG uptake measured as standardized uptake value (SUV) and HIF-1α expression in solid tumors. METHODS: MEDLINE library, SCOPUS and EMBASE data bases were screened for relationships between SUVmax and HIF-1a up to August 2019. Overall, 21 studies with 1154 patients were identified. The following data were extracted from the literature: authors, year of publication, number of patients, and correlation coefficients. RESULTS: Correlation coefficients between SUV and HIF-1α ranged from -0.51 to 0.71. The pooled correlation coefficient was 0.27, (95% CI = [0.14; 0.41]). Furthermore, correlation coefficients for specific tumor entities were calculated. For this sub-analysis, data for primary tumors with more than two reports were included. The calculated correlation coefficients in the analyzed subgroups were as follows: head and neck squamous cell carcinoma: ρ = 0.25 (95% CI = [0.07; 0.42]); non-small lung cell cancer: ρ = 0.27 (95% CI = [-0.14; 0.67]); uterine cervical cancer: ρ = -0.09 (95% CI = [- 0.89; 0.71]); thymic tumors: ρ = 0.39 (95% CI = [0.04; 0.58]) CONCLUSION: Published literature suggests wide heterogeneity and weak correlation between intensity of FDG uptake measured as SUVmax and expression of HIF-1a both in solid tumors in general and also in specific tumor subgroups. Because HIF-1α is a very important theranostic target, prospective state of the art studies are needed to elucidate the true potential of FDG PET in assessment of HIF-1α activity in solid tumors

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The Influence of Blood Glucose Levels on [18F]Fluorodeoxyglucose (Fdg) Uptake in Cancer: A Pet Study in Liver Metastases from Colorectal Carcinomas

Tumori Journal ◽

10.1177/030089169708300407 ◽

1997 ◽

Vol 83 (4) ◽

pp. 748-752 ◽

Cited By ~ 47

Author(s):

Flavio Crippa ◽

Cecilia Gavazzi ◽

Federico Bozzetti ◽

Carlo Chiesa ◽

Claudio Pascali ◽

...

Keyword(s):

Blood Glucose ◽

Liver Metastases ◽

Fdg Pet ◽

Kinetic Method ◽

Standardized Uptake Value ◽

Colorectal Carcinomas ◽

Glucose Loading ◽

Fdg Uptake ◽

Glucose Levels ◽

Blood Glucose Levels

Aims and background To study the influence of blood glucose levels on the clinical reliability of positron emission tomography (PET) with [18F]-2-fluoro-2-deoxy-D-glucose (FDG) in the detection of liver metastases from colorectal carcinomas and in the analysis of tumor uptake of FDG. Methods After having given their informed consent, 8 patients with 20 liver metastases (mean size, 31.5 mm; range, 10–75 mm) detected by means of CT were submitted to a first FDG-PET examination under fasting conditions and, 2 days later, to a second FDG-PET examination performed after iv infusion of a glucose solution (4 mg/kg/min for 2 hrs). The results of the two studies were compared in each patient, considering both the localization of the metastases and the FDG uptake in the lesions. A non-kinetic method was used, calculating the Standardized Uptake Value (SUV). Results All 20 metastases were clearly visible on FDG-PET under fasting conditions. Moreover, in 2 patients FDG-PET detected a number of unknown liver metastases. The blood glucose levels after glucose infusion were significantly higher than the levels under fasting conditions, 158 ± 13.8 mg/100 ml (mean ± sd) and 92.4 ± 10.2, respectively (P « 0.001), and the quality of the FDG-PET images showed a marked deterioration. FDG-PET was unable to detect 6 of the 20 lesions and another 10 lesions were localized less clearly. Moreover, 80% of the unknown liver metastases were not detected after glucose loading. The SUVs of metastases decreased from 9.4 ± 5.7 (mean ± sd) under fasting conditions to 4.3 ± 8.3 after glucose loading (P « 0.001). Conclusions FDG-PET studies may be particularly unreliable under conditions of high levels of blood glucose. Therefore, patients entering FDG-PET studies should fast, and blood glucose concentration needs to be taken into account when evaluating FDG uptakes in follow-up studies.

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The clinical impact of incidental sellar uptake on F-18 FDG PET/CT

International Journal of Endocrine Oncology ◽

10.2217/ije-2018-0004 ◽

2019 ◽

Vol 6 (2) ◽

pp. IJE15

Author(s):

Zehra Pınar Koç ◽

Pelin Özcan Kara ◽

Emel Sezer ◽

Kadir Eser ◽

Anıl Özgür

Keyword(s):

Fdg Pet ◽

Standardized Uptake Value ◽

Sellar Region ◽

Primary Tumors ◽

Fdg Uptake ◽

Pet Ct ◽

Frequent Finding ◽

Metastatic Involvement ◽

Fdg Pet Ct

Aim: The most frequent finding associated with incidental fluorodeoxyglucose (FDG) uptake in sellar region in oncologic F-18 FDG PET/CT is adenoma. However, reports of metastatic involvement exist. We investigated the clinical significance of incidental FDG uptake in this region. Materials & method: 34 patients with several primary tumors who were referred for staging, restaging or treatment response via F-18 FDG PET/CT were included. Images were reviewed and patients with significant FDG uptake in the sellar region were referred. Results: Mean lesion diameter was 11.9 ± 4.9 mm and mean standardized uptake value was 8.2 ± 6.1. Thirteen patients underwent MRI, and the others underwent follow-up F-18 FDG PET/CT. MRI revealed metastatic involvement in nine patients and macro- or micro-adenoma in four. Metastatic patients also had other lesions, yet management did not change. Conclusion: FDG accumulation in the sellar region might be associated with metastasis or adenoma. However, it did not change management. Future studies are warranted.

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Early Changes in [18F]FDG Uptake as a Readout for PI3K/Akt/mTOR Targeted Drugs in HER-2-Positive Cancer Xenografts

Molecular Imaging ◽

10.1155/2021/5594514 ◽

2021 ◽

Vol 2021 ◽

pp. 1-14

Author(s):

Yanina Dockx ◽

Christel Vangestel ◽

Tim Van den Wyngaert ◽

Manon Huizing ◽

Sven De Bruycker ◽

...

Keyword(s):

Fdg Pet ◽

Human Cancer ◽

Standardized Uptake Value ◽

Early Response ◽

Pi3k Pathway ◽

Fdg Uptake ◽

Human Cancer Cells ◽

Response Biomarker ◽

Her 2 ◽

18F Fdg

We investigated the potential use of [18F]FDG PET as a response biomarker for PI3K pathway targeting therapies in two HER-2-overexpressing cancer models. Methods. CD-1 nude mice were inoculated with HER-2-overexpressing JIMT1 (trastuzumab-resistant) or SKOV3 (trastuzumab-sensitive) human cancer cells. Animals were treated with trastuzumab, everolimus (mTOR inhibitor), PIK90 (PI3K inhibitor), saline, or combination therapy. [18F]FDG scans were performed at baseline, two, and seven days after the start of the therapy. Tumors were delineated on CT images and relative tumor volumes (RTV) and maximum standardized uptake value (SUVmax) were calculated. Levels of pS6 and pAkt on protein tumor lysates were determined with ELISA. Results. In the SKOV3 xenografts, all treatment schedules resulted in a gradual decrease in RTV and delta SUVmax (ΔSUVmax). For all treatments combined, ΔSUVmax after 2 days was predictive for RTV after 7 days ( r = 0.69 , p = 0.030 ). In JIMT1 tumors, monotherapy with everolimus or PIK90 resulted in a decrease in RTV ( − 30 % ± 10 % and − 20 % ± 20 % , respectively) and ΔSUVmax ( − 39 % ± 36 % and − 42 % ± 8 % , respectively) after 7 days of treatment, but not earlier, while trastuzumab resulted in nonsignificant increases compared to control. Combination therapies resulted in RTV and ΔSUVmax decrease already at day 2, except for trastuzumab+everolimus, where an early flare was observed. For all treatments combined, ΔSUVmax after 2 days was predictive for RTV after 7 days ( r = 0.48 , p = 0.028 ), but the correlation could be improved when combination with everolimus ( r = 0.59 , p = 0.023 ) or trastuzumab ( r = 0.69 , p = 0.015 ) was excluded. Conclusion. Reduction in [18F]FDG after 2 days correlated with tumor volume changes after 7 days of treatment and confirms the use of [18F]FDG PET as an early response biomarker. Treatment response can however be underestimated in schedules containing trastuzumab or everolimus due to temporary increased [18F]FDG uptake secondary to negative feedback loop and crosstalk between different pathways.

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Choice of anesthesia and data analysis method strongly increases sensitivity of 18F-FDG PET imaging during experimental epileptogenesis

PLoS ONE ◽

10.1371/journal.pone.0260482 ◽

2021 ◽

Vol 16 (11) ◽

pp. e0260482

Author(s):

Ina Jahreis ◽

Pablo Bascuñana ◽

Tobias L. Ross ◽

Jens P. Bankstahl ◽

Marion Bankstahl

Keyword(s):

Data Analysis ◽

Glucose Metabolism ◽

Pet Imaging ◽

Fdg Pet ◽

Regional Analysis ◽

Statistical Parametric Mapping ◽

Tracer Uptake ◽

Chronic Epilepsy ◽

Conscious Rats ◽

Fdg Uptake

Purpose Alterations in brain glucose metabolism detected by 2-deoxy-2-[18F]-fluoro-D-glucose (18F-FDG) positron emission tomography (PET) may serve as an early predictive biomarker and treatment target for epileptogenesis. Here, we aimed to investigate changes in cerebral glucose metabolism before induction of epileptogenesis, during epileptogenesis as well as during chronic epilepsy. As anesthesia is usually unavoidable for preclinical PET imaging and influences the distribution of the radiotracer, four different protocols were compared. Procedures We investigated 18F-FDG uptake phase in conscious rats followed by a static scan as well as dynamic scans under continuous isoflurane, medetomidine-midazolam-fentanyl (MMF), or propofol anesthesia. Furthermore, we applied different analysis approaches: atlas-based regional analysis, statistical parametric mapping, and kinetic analysis. Results At baseline and compared to uptake in conscious rats, isoflurane and propofol anesthesia resulted in decreased cortical 18F-FDG uptake while MMF anesthesia led to a globally decreased tracer uptake. During epileptogenesis, MMF anesthesia was clearly best distinctive for visualization of prominently increased glucometabolism in epilepsy-related brain areas. Kinetic modeling further increased sensitivity, particularly for continuous isoflurane anesthesia. During chronic epilepsy, hypometabolism affecting more or less the whole brain was detectable with all protocols. Conclusion This study reveals evaluation of anesthesia protocols for preclinical 18F-FDG PET imaging as a critical step in the study design. Together with an appropriate data analysis workflow, the chosen anesthesia protocol may uncover otherwise concealed disease-associated regional glucometabolic changes.

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