Fluorodeoxyglucose Positron Emission Tomography Scans Research Articles

The Role of Magnetic Resonance Spectroscopy, Magnetic Resonance Perfusion and Positron Emission Tomography-Computed Tomography in Post-Radiotherapy Evaluation of Gliomas to Detect Recurrence

Abstract Background and Aim: In this article, the findings of magnetic resonance spectroscopy (MRS), magnetic resonance (MR) perfusion, and positron emission tomography (PET) will be compared and finally correlated with the histopathological examination in all patients having positive imaging findings. The sensitivity and specificity of MRS, MR perfusion, and PET in diagnosing residual/recurrent glioma would be estimated using the histopathological diagnosis as a gold standard. Materials and Methods: Twenty-nine cases of intracranial glioma that had undergone surgery, followed by adjuvant radiotherapy were enrolled in the study. All 29 patients underwent MRS, MR perfusion, and fluorodeoxyglucose (FDG) PET. Results: The sensitivity of MRS to detect recurrence was found to be 83.3% and specificity was 100%. The positive predictive value (PPV) and negative predictive value (NPV) were 100% and 33.3%, respectively. The diagnostic accuracy of MRS was found to be 84.6%. The sensitivity and specificity of MR perfusion to detect recurrence were 91.7% and 100%, respectively. The diagnostic accuracy of MR perfusion is 92.3%. The NPV of MR perfusion was found to be 50%. The sensitivity of PET scans to detect recurrence was 83.3% and specificity was 100%. The PPV of PET was 100% and the NPV was 33.3%. The diagnostic accuracy of the PET scan was found to be 84.6%. Conclusions: Our study shows that all three modalities are useful, however, MR perfusion study is better than MRS and FDG PET in detecting recurrence. MR contrast with perfusion and spectroscopy and FDG PET scan should be included in the protocol for radiotherapy-treated gliomas to differentiate between radiation necrosis, postradiotherapy gliosis, and recurrent/residual tumor.

Clinicoradiological and neuropathological evaluation of primary progressive aphasia

BackgroundPrimary progressive aphasia (PPA) defines a group of neurodegenerative disorders characterised by language decline. Three PPA variants correlate with distinct underlying pathologies: semantic variant PPA (svPPA) with transactive response DNA-binding...

PET-scan in diagnosis of non-bacterial thrombotic endocarditis: a case report

BackgroundNon-bacterial thrombotic endocarditis (NBTE), also known as marantic endocarditis or Libman–Sacks endocarditis, is a rare non-infectious condition affecting mostly the left-sided heart valves of patients who, most often, suffer from malignancies and connective tissue disorders. Herein, we present a case of a male patient with marantic endocarditis due to occult lung adenocarcinoma.Case presentationThe patient fulfilled the modified Duke’s criteria of possible bacterial endocarditis of the aortic valve; however, multiple blood cultures and serological tests were negative. In addition, the patient’s clinical course was constantly deteriorating. Thus, a fluorodeoxyglucose-positron emission tomography (FDG-PET) scan was conducted. This examination revealed multiple positive thoracic lymph node groups, as well as a positive lung lesion. The patient underwent aortic valve replacement and lymph biopsies during the operation established the diagnosis of solid/micropapillary lung adenocarcinoma and consequently of the non-bacterial thrombotic endocarditis.ConclusionsAdvanced imaging techniques may be needed to diagnose NBTE and should be kept in mind when the Duke criteria are not definite. Clinical suspicion is key to implement these premises. However, the exact role of the PET-scan has yet to be specified.

Utility of fluoro-deoxy-glucose positron emission tomography (FDG-PET) to predict a pelvic lymph node involvement (LNI) in patients (pts) with muscle-invasive bladder cancer (MIBC) enrolled in neoadjuvant therapy trials.

527 Background: FDG-PET is reported to have limited utility in pts with MIBC. However, standard computed tomography (CT) imaging can often underestimate disease extent, and its role in predicting a pathological pelvic lymph node involvement (LNI) is very limited. Previous findings from PURE-01 trial reported a potential use of FDG-PET to exclude the few pts with T2-4N0M0 and pelvic LN uptake from neoadjuvant trials with immune-checkpoint inhibitors (ICI; PMID: 33071107). The aim of this study was to extend these findings to a wider range of experimental therapies. Methods: We collected the data of pts with clinical stage T2-4N0-1M0 MIBC included in past and ongoing neoadjuvant trials sponsored by our center, including single agent or combination of immune-checkpoint inhibitors (ICI), ICI+chemotherapy (ChT), standard ChT and sacituzumab govitecan. All pts had predominant urothelial carcinoma (UC) histology and were staged with standard thorax-abdomen CT scan and with PET/CT scan during screening and after treatment, before radical cystectomy (RC). PET/CT images were evaluated qualitatively for increased or abnormal areas of FDG uptake with corresponding anatomic alterations in CT slices. All pts underwent templated pelvic lymph node dissection (LND) with packeted node submission. Multivariable logistic regression analyses (MVA) for pathological LNI prediction were run, including cT-stage and the presence of variant histologies (VH). Results: A total of 149 pts (298 PET scans) were identified, treated between 02/2017 and 08/2023. 112 pts (75.2%) received ICI, 26 (17.4%) ICI+ChT, 11 (7.4%) the remaining therapies. 36 pts (24%) had a VH, 72 (48%) a cT3-4 stage, and 12 (8.1%) a cN1 stage. In total, 20 (13%) and 16 (11%) pts had PET+ pre- and post-therapy, respectively. The accuracy of FDG-PET and CT scan in predicting LNI in overall pts was similar, both pre-therapy (85.3% and 86.7%) and post therapy (86.7%, 84.6%), the only exceptions being a lower accuracy of PET to predict presacral LNI (76.6%, 78.8% pre- and post-therapy) and in VH pre-therapy (84.3% vs 90.9% PET vs CT). A pre-therapy FDG uptake significantly predicted a pathological LNI in MVA (OR: 17.8, 95%CI: 4.18-94.86, p<0.001, AUC: 0.89), with consistent results in T2-4N0M0 cohort (OR: 18.17, 95%CI: 4.15-99.25, p<0.001, AUC: 0.84). Conclusions: Despite the proportion of FDG-PET positive pts was modest in T2-4N0-1M0 MIBC, we were able to confirm that these pts were predicted to be poor responders to neoadjuvant therapies regardless of the type of treatment. FDG-PET had lower prediction ability of LNI in presacral LN region and in pts with a VH. This information should be critically considered for patient selection in neoadjuvant therapy trials.

Patterns of metastatic spread and tumor burden in unselected cancer patients using PET imaging: Implications for the oligometastatic spectrum theory

Introduction and backgroundMetastatic disease has been proposed as a continuum, with no clear cut-off between oligometastatic and polymetastatic disease. This study aims to quantify tumor burden and patterns of spread in unselected metastatic cancer patients referred for PET-based staging, response assessment of restaging. Materials and methodsAll oncological fluorodeoxyglucose (FDG-) and prostate-specific membrane antigen (PSMA-) positron emission tomography (PET) scans conducted at a single academic center in 2020 were analyzed. Imaging reports of all patients with metastatic disease were reviewed and assessed. ResultsFor this study, 7,000 PET scans were screened. One third of PET scans (n = 1,754; 33 %) from 1,155 unique patients showed presence of metastatic disease from solid malignancies, of which 601 (52 %) and 554 (48 %) were classified as oligometastatic (maximum 5 metastases) and polymetastatic (>5 metastases), respectively. Lung and pleural cancer, skin cancer, and breast cancer were the most common primary tumor histologies with 132 (23.8 %), 88 (15.9 %), and 72 (13.0 %) cases, respectively. Analysis of the number of distant metastases showed a strong bimodal distribution of the metastatic burden with 26 % of patients having one solitary metastasis and 43 % of patients harboring >10 metastases. Yet, despite 43 % of polymetastatic patients having >10 distant metastases, their pattern of distribution was restricted to one or two organs in about two thirds of patients, and there was no association between the number of distant metastases and the number of involved organs. ConclusionThe majority of metastatic cancer patients are characterized by either a solitary metastasis or a high tumor burden with >10 metastases, the latter was often associated with affecting a limited number of organs. These findings support both the spectrum theory of metastasis and the seed and soil hypothesis and can support in designing the next generation of clinical trials in the field of oligometastatic disease.

Comparing Symmetric Dimethylarginine and Amyloid-β42 as Predictors of Alzheimer's Disease Development.

Physicians may soon be able to diagnose Alzheimer's disease (AD) in its early stages using fluid biomarkers like amyloid. However, it is acknowledged that additional biomarkers need to be characterized which would facilitate earlier monitoring of AD pathogenesis. To determine if a potential novel inflammation biomarker for AD, symmetric dimethylarginine, has utility as a baseline serum biomarker for discriminating prodromal AD from cognitively unimpaired controls in comparison to cerebrospinal fluid amyloid-β42 (Aβ42). Data including demographics, magnetic resonance imaging and fluorodeoxyglucose-positron emission tomography scans, Mini-Mental State Examination and Functional Activities Questionnaire scores, and biomarker concentrations were obtained from the Alzheimer's Disease Neuroimaging Initiative for a total of 146 prodromal AD participants and 108 cognitively unimpaired controls. Aβ42 (p = 0.65) and symmetric dimethylarginine (p = 0.45) were unable to predict age-matched cognitively unimpaired controls and prodromal AD participants. Aβ42 was negatively associated with regional brain atrophy and hypometabolism as well as cognitive and functional decline in cognitively unimpaired control participants (p < 0.05) that generally decreased in time. There were no significant associations between Aβ42 and symmetric dimethylarginine with imaging or neurocognitive biomarkers in prodromal AD patients. Correlations were smaller between Aβ42 and neuropathological biomarkers over time and were absent in prodromal AD participants, suggesting a plateau effect dependent on age and disease stage. Evidence supporting symmetric dimethylarginine as a novel biomarker for AD as a single measurement was not found.

Mapping whole brain effects of infrared neural stimulation with positron emission tomography

Abstract The combination of neuroimaging and targeted neuromodulation is a crucial tool to gain a deeper understanding of neural networks at a circuit level. Infrared neurostimulation (INS) is a promising optical modality that allows to evoke neuronal activity with high spatial resolution without need for the introduction of exogenous substances in the brain. Here, we report the use of whole-brain functional [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) imaging during INS in the dorsal striatum, performed using a multifunctional soft neural probe. We demonstrate the possibility to identify multi-circuit connection patterns in both cortical and subcortical brain regions within a single scan. By using a bolus plus infusion FDG-PET scanning protocol, we were able to observe the metabolic rate evolution in these regions during the experiments and correlate its variation with the onset of the INS stimulus. Due to the focality of INS and the large amount of viable molecular targets for positron emission tomography (PET), this novel approach to simultaneous imaging and stimulation is highly versatile. This pilot study can pave the way to further understand the brain connectivity on a global scale.

An Unusual Cause of Bilateral Adrenal Incidentaloma: A Case Report of Primary Adrenal Lymphoma

Primary adrenal lymphoma (PAL) is an extremely rare among the causes of adrenal incidentaloma. Most were diagnosed with adrenal insufficiency and B symptoms (unexplained weight loss, night sweats, fever). This article presented a 57-year-old woman who was investigated for bilateral adrenal masses found incidentally on computed tomography (CT). Physical examination and laboratory tests revealed no evidence of adrenal insufficiency or B symptoms. Only 24-hour urinary metanephrine and normetanephrine excretion were increased. Tumour F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET/CT) scan showed the greatest dimension was 14 cm in the left adrenal mass and the maximum standardized uptake value (SUV max) was 26.1 (relative to mean SUV in the normal liver parenchyma, which was 2). An adrenal biopsy was performed after taking adequate precautions against the possibility of a catecholamine crisis. Histopathology revealed high-grade B-cell lymphoma. Bone marrow involvement and brain metastasis were not observed. She received the R-EPOCH (rituximab, etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin) regimen and intrathecal methotrexate therapy as central nervous system prophylaxis. The patient responded well to treatment, and close clinical follow-up continues. PAL should always be considered when a bilateral adrenal mass is detected.

Arterial spin labeling (ASL-MRI) versus fluorodeoxyglucose-PET (FDG-PET) in diagnosing dementia: a systematic review and meta-analysis

BackgroundDementia is generally caused by neurodegenerative diseases affecting the brain, which leads to a progressive neurocognitive decline characterized by inability to perform major higher functioning tasks. Fluorodeoxyglucose-positron emission tomography (FDG-PET) scan is one of the main imaging tests performed for diagnostic purposes. However, with FDG-PET being quite expensive and not widely available, an attempt to find an alternative is set. Arterial-spin-labelling magnetic resonance imaging (ASL-MRI) is an increasingly investigated substitute to FDG-PET for the diagnosis of dementia. Thereby, the main purpose of this systematic review and meta-analysis is to compare the diagnostic ability of FDG-PET and ASL-MRI in detecting dementia.MethodsPRISMA checklist for diagnostic test accuracy was employed in outlining this paper. A literature search was done using several search engines including PubMed, Core, and Cochrane. Two researchers (HH and SH) extracted the essential information from all included articles. Risk of bias was evaluated by the Quality Assessment of Diagnostic Accuracy Studies tool, version 2 (QUADAS-2). A qualitative analysis and summary of studies’ results were provided. In addition, a meta-analysis was executed based on the studies which involved sensitivity and specificity measures of diagnostic accuracy.ResultsFourteen total studies were included in the given review. Qualitative analysis of the articles showed that nine studies demonstrated an overlap between metabolic and perfused brain maps as derived by FDG-PET and ASL-MRI respectively, while the remaining five studies registered significant differences across both modalities, with superiority to FDG-PET. As for the meta-analysis implemented, summary ROC-curve analysis revealed that FDG-PET performed better than ASL-MRI, with pooled sensitivity being significantly higher for FDG-PET.ConclusionsComparing the diagnostic value of FDG-PET and ASL-MRI, the results of this systematic review and meta-analysis indicate that FDG-PET still has an advantage over ASL-MRI. Such implication could be related to the technical differences relating to both modalities, with ASL-MRI having lower temporal resolution. It’s worth mentioning that specificity was rather quite similar among both modalities and some studies found an overridden metabolic and perfused images. These findings call for future research to focus their scope of investigation while exploring the diagnostic value of ASL-MRI.

Deep learning based diagnosis of Alzheimer’s disease using FDG-PET images

PurposeThe aim of this study is to develop a deep neural network to diagnosis Alzheimer's disease and categorize the stages of the disease using FDG-PET scans. Fluorodeoxyglucose positron emission tomography (FDG-PET) is a highly effective diagnostic tool that accurately detects glucose metabolism in the brain of AD patients. Material and methodsIn this work, we have developed a deep neural network using FDG-PET to discriminate Alzheimer's disease subjects from stable mild cognitive impairment (sMCI), progressive mild cognitive impairment (pMCI), and cognitively normal (CN) cohorts. A total of 83 FDG-PET scans are collected from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database, including 21 subjects with CN, 21 subjects with sMCI, 21 subjects with pMCI, and 20 subjects with AD. ResultsThe method has achieved remarkable accuracy rates of 99.31% for CN vs. AD, 99.88% for CN vs. MCI, 99.54% for AD vs. MCI, and 96.81% for pMCI vs. sMCI. Based on the experimental results. ConclusionThe results show that the proposed method has a significant generalisation ability as well as good performance in predicting the conversion of MCI to AD even in the absence of direct information. FDG-PET is a well-known biomarker for the identification of Alzheimer's disease using transfer learning.

FRI531 IgG4 Related Mass -forming Thyroid Disease: Two Case Reports

Abstract Disclosure: R.S. Braham: None. C. Droumaguet: None. M. Vitellius: None. J. Tran-van-nhieu: None. E. Béquignon: None. P. Desgranges: None. N. Limal: None. M. Mahevas: None. B. Godeau: None. IgG4 thyroiditis is an invasive fibrotic process involving the thyroid in a systemic disease. It is a rare inflammatory autoimmune disease with insidious presentation and nonspecific symptoms.We describe two unusual cases of mass forming IgG4 thyroiditis that were diagnosed recently in our department. The first case is about a 42-year-old woman who has a history of Hashimoto thyroiditis with hypothyroidism presenting with a rapid goiter growth, neck pain, dysphagia and hoarseness. A lymphoma was suspected. Ultrasonography shows heterogeneous hypoechoic lesions that may infiltrate the perithyroid muscles. Fine-needle aspiration (FNA) was suspicious of IgG4 infiltrative disease which was confirmed by microbiopsy. Only the thyroid was hypermetabolic on fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) Scan. No improvement under corticosteroid treatment and Rituximab. Surgery was planified to relieve pressure symptoms. The thyroid surgery was very difficult because of the extensive fibrosis and only a biopsy was performed, confirming the diagnosis and excluding malignancy. The second case is about a 68-year-old woman with a history of hypertension and Graves disease presented with a neck right mass that was suspected to be a paraganglioma, hypermetabolic on FDG PET scan with no other localisation. This mass was surrounding the right primitive carotid artery, associated with thrombi of the internal jugular vein. FNA and microbiopsy found a fibrotic non specific tissue. Thyroidectomy and surgical biopsy of the neck mass were performed with histopathology confirming IgG4 disease on the thyroid gland with fibrosis. There were no hypocalcemia in the two cases and no other localisation. IgG4 related mass-forming thyroiditis is an extremely rare disease. It is now a recognizable pattern of IgG4 thyroiditis, and has as differential diagnosis Hashimoto’s thyroiditis, Graves disease and thyroidal carcinoma.We will discuss through these cases the different clinical presentation of this rare disease, the diagnostic tools, the treatment and the long term follow up. Presentation: Friday, June 16, 2023

A Surinamese Woman with Severe Hypercalcemia and Ascites

A 60-year-old Surinamese woman was admitted to the department of Hematology because of refractory hypercalcemia and weight loss. Three months earlier she presented with aphasia and ataxia due to hypercalcemia (4.32 mmol/L). She was treated with intravenous fluids, calcitonin and pamidronate, resulting in normocalcemia. Serum Parathyroid Hormone (PTH) was 1.93 pmol/L. At that time, a bone marrow and Peripheral Blood (PB) examination and Fluorodeoxyglucose-Positron Emission Tomography (FDG-PET) scan did not show any abnormalities. Physical examination revealed multiple papules and diffuse scaling (Figure 1A). Current PB analysis demonstrated anemia (10 g/dL), thrombocytopenia (103 x 109/L), leukocytosis (20.5x 109/L; 38% lymphocytes), hypercalcemia (3.58 mmol/L) and elevated LDH (652 U/L). FDG-PET/CT at this time point showed ascites and splenomegaly.

The impact of tau deposition and hypometabolism on cognitive impairment and longitudinal cognitive decline.

Tau and neurodegeneration strongly correlate with cognitive impairment, as compared to amyloid. However, their contribution in explaining cognition and predicting cognitive decline in memory clinics remains unclarified. We included 94 participants with Mini-Mental State Examination (MMSE), tau positron emission tomography (PET), amyloid PET, fluorodeoxyglucose(FDG) PET, and MRI scans from Geneva Memory Center. Linear regression and mediation analyses tested the independent and combined association between biomarkers, cognitive performance, and decline. Linear mixed-effects and Cox proportional hazards models assessed biomarkers' prognostic values. Metabolism had the strongest association with cognition (r=0.712; p<0.001), followed by tau (r=-0.682; p<0.001). Neocortical tau showed the strongest association with cognitive decline (r=-0.677; p<0.001). Metabolism mediated the association between tau and cognition and marginally mediated the one with decline. Tau positivity represented the strongest risk factor for decline (hazard ratio=32). Tau and neurodegeneration synergistically contribute to global cognitive impairment while tau drives decline. The tau PET superior prognostic value supports its implementation in memory clinics. Hypometabolism has the strongest association with concurrent cognitive impairment. Neocortical tau pathology is the main determinant of cognitive decline over time. FDG-PET has a superior value compared to MRI as a measure of neurodegeneration. The prognostic value of tau-PET exceeded all other neuroimaging modalities.

Stroke-like presentation of acute toxic leukoencephalopathy due to capecitabine treatment with extensive intramyelinic edema.

Stroke-like presentation of acute toxic leukoencephalopathy due to capecitabine treatment with extensive intramyelinic edema.

Differential effects of sleep on brain structure and metabolism at the preclinical stages of AD.

Poor sleep quality is associated with cognitive outcomes in Alzheimer's disease (AD). We analyzed the associations between self-reported sleep quality and brain structure and function in cognitively unimpaired (CU) individuals. CU adults (N=339) underwent structural magnetic resonance imaging, lumbar puncture, and the Pittsburgh Sleep Quality Index (PSQI) questionnaire. A subset (N=295) performed [18F] fluorodeoxyglucose positron emission tomography scans. Voxel-wise associations with gray matter volumes (GMv) and cerebral glucose metabolism (CMRGlu) were performed including interactions with cerebrospinal fluid (CSF) AD biomarkers status. Poorer sleep quality was associated with lower GMv and CMRGlu in the orbitofrontal and cingulate cortices independently of AD pathology. Self-reported sleep quality interacted with altered core AD CSF biomarkers in brain areas known to be affected in preclinical AD stages. Poor sleep quality may impact brain structure and function independently from AD pathology. Alternatively, AD-related neurodegeneration in areas involved in sleep-wake regulation may induce or worsen sleep disturbances. Highlights Poor sleep impacts brain structure and function independent of Alzheimer's disease (AD) pathology. Poor sleep exacerbates brain changes observed in preclinical AD. Sleep is an appealing therapeutic strategy for preventing AD.

18 F FDG PET-CT Scan Findings in a Rare Case of Pulmonary Hyalinising Granuloma

Pulmonary hyalinising granuloma (PHG) is a benign lung disease. It is a rare disease of unknown aetiology. Less than 150 cases are reported. Its aetiology has not been established but the underlying cause is thought to be the deposition of an immune complex in lung parenchyma or autoimmune process. It usually presents as solitary or multiple lung nodules. PHG has a good prognosis. Solitary lesions are treated by resection and multiple lesions are treated with immunosuppressive drugs with variable responses. Here, we report a case of a 68-year-old female who presented with two episodes of haemoptysis. On investigation, chest computed tomography (CT) reveals multiple lung nodules on both sides, 18 F fluorodeoxyglucose (FDG) positron emission tomography and CT scan reveal mildly FDG avid and non-FDG avid subpleural and parenchymal nodular lesions of varying sizes with calcification noted scattered diffusely in both lung fields. Pathology findings are suggestive of fibrocollagenous tissue with tiny foci of epithelial cells arranged as papillae, cuboid cells with minimal atypia, mitosis, and necrosis not seen and no lymphoid tissue seen, suggestive of PHG.

알츠하이머병에서 APOE e4 유전형과 인지기능, 뇌 부피, 당 대사량 그리고 뇌 아밀로이드 침착과의 연관성

Objective: The purpose of this study is to investigate the association of the apolipoprotein E (APOE) e4 genotype with cognition, brain volume, glucose metabolism, and amyloid deposition in patients with Alzheimer disease (AD).&#x0D; Methods: This is cross-sectional study of 69 subjects with AD. All subjects were divided into carriers and non-carriers of the e4 allele. Forty APOE e4 carriers and 29 APOE e4 non-carriers underwent neuropsychological, structural magnetic resonance imaging, [18F]fluorodeoxyglucose positron emission tomography scans (PET) and [18F]florbetaben amyloid PET. Analysis of covariance was conducted to compare the differences on cognition, brain volume, glucose metabolism and amyloid deposition between APOE e4 carriers and non-carriers after controlling demographics.&#x0D; Results: APOE e4 carriers had 50% lower scores of Seoul Verbal Learning Test (delayed recall) compared to non-carriers (0.88±1.65 vs. 1.76±1.75, p&lt;0.05). However, APOE e4 carriers performed better on other cognitive tests than non-carriers (Korean version of Boston Naming Test [11.04±2.55 vs. 9.66±2.82, p&lt;0.05], Rey Complex Figure Test [25.73±8.56 vs. 20.15±10.82, p&lt;0.05], and Stroop test [color response] [48.28±26.33 vs. 31.56±27.03, p&lt;0.05]). APOE e4 carriers had slightly smaller hippocampal volume than non-carriers (3.09±0.38 vs. 3.32±0.38, p&lt;0.05), but greater total brain cortical thickness (1.45±1.55 vs. 1.37±1.24, p&lt;0.05). Amyloid deposition did not differ significantly between APOE e4 carriers and non-carriers, and no significant difference in glucose metabolism was found between groups.&#x0D; Conclusion: We found that APOE e4 genotype is associated with cognition, brain volume in AD, suggesting that APOE e4 genotype could play an important role in the underlying pathogenesis of AD.

Longitudinal brain and skeletal muscle FDG-PET changes in people with stiff person syndrome spectrum disorders (P4-5.021)

<h3>Objective:</h3> To describe changes in fluorodeoxyglucose positron emission tomography (FDG-PET) findings in the brain and muscles of individuals with stiff person syndrome spectrum disorders (SPSD) longitudinally. <h3>Background:</h3> SPSD includes multiple clinical phenotypes that rarely can be paraneoplastic in origin. An FDG-PET scan is frequently obtained as part of the malignancy work-up, and abnormal metabolic activity unrelated to malignancy has been shown to occur in both the brain and skeletal muscles of patients with SPSD. However, it is unclear if such findings persist or change over time. <h3>Design/Methods:</h3> A retrospective study was performed of patients with SPSD who were seen at Johns Hopkins SPS Center from 2009 to March 2022, with at least two FDG-PET studies in the medical record with source images of sufficient quality for comparison. Quantitative data was extracted from dedicated brain FDG-PET scans using NeuroQ™, which calculates Z-scores of 47 brain regions compared to healthy controls. Body FDG-PET scans will be reviewed qualitatively by a blinded nuclear medicine radiologist to detect the presence and pattern of hypermetabolism in skeletal muscle. Patients’ clinical characteristics, including type of treatment, will be correlated with PET data. <h3>Results:</h3> Out of 98 SPSD patients who underwent an FDG-PET scan, 10 were identified that met inclusion criteria. Median age at time of SPSD onset was 51±15.8 years, 60% were males, and 60% were black. Mean duration from symptom onset to first FDG-PET scan was 0.78±0.62 years. The majority of patients had SPS-plus phenotype. All patients were seropositive for an SPSD-associated antibody and received an immune therapy. Preliminary data demonstrate that all patients had at least 1 region of dysmetabolism on initial brain scan, and at least 3 regions on follow-up. <h3>Conclusions:</h3> We will present longitudinal metabolic changes in brain and body FDG-PET scans of patients with SPSD, and determine if any changes observed are associated with clinical characteristics. <b>Disclosure:</b> Dr. Roman has nothing to disclose. The institution of Dr. Wang has received research support from Genentech. Dr. Sadaghiani has nothing to disclose. Dr. Newsome has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Autobahn. Dr. Newsome has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Biogen. Dr. Newsome has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Genentech. Dr. Newsome has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Novartis. Dr. Newsome has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for EMD Serono. Dr. Newsome has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Greenwich Biosciences. Dr. Newsome has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Bristol Myers Squibb. Dr. Newsome has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Horizon Therapeutics. The institution of Dr. Newsome has received research support from Biogen. The institution of Dr. Newsome has received research support from Genentech/Roche. The institution of Dr. Newsome has received research support from Department of Defense. The institution of Dr. Newsome has received research support from Patient Centered Outcomes Research Institute. The institution of Dr. Newsome has received research support from National MS Society. The institution of Dr. Newsome has received research support from The Stiff Person Syndrome Research Foundation. Dr. Newsome has received personal compensation in the range of $5,000-$9,999 for serving as a Clinical adjudication committee member for clinical trial with medDay Pharmaceuticals. Dr. Newsome has received personal compensation in the range of $10,000-$49,999 for serving as a Lead PI for Clinical Trial with Roche.

Accuracy of predicting surgical outcomes using interictal electrical source imaging in patients with MRI-negative intractable epilepsy

ObjectiveWe investigated the accuracy of interictal electrical source imaging (II-ESI) in localizing the epileptogenic zone in MRI-negative epilepsy patients who underwent epilepsy surgery. We also aimed to compare II-ESI's utility with other presurgical investigations and its role in guiding intracranial electroencephalography (iEEG) planning. MethodsWe retrospectively reviewed the medical records of patients with operated MRI-negative intractable epilepsy at our center between 2010 and 2016. All patients underwent video electroencephalography (EEG) monitoring, high-resolution MRI, 18 fluorodeoxyglucose positron emission tomography (FDG-PET) scans, ictal single-photon emission computed tomography (SPECT) and intracranial EEG (iEEG) monitoring. We computed II-ESI following the visual identification of interictal spikes, and outcomes were determined using Engel’s classification at 6 months after surgery. ResultsAmong 21 operated MRI-negative intractable epilepsy patients, 15 had sufficient data for II-ESI analysis. Of these, nine patients (60%) showed favorable outcomes corresponding to Engle's classification I and II. The localization accuracy of II-ESI was 53%, which was not significantly different from those of FDG-PET and ictal SPECT (47% and 45%, respectively). Among the patients, iEEG did not cover the areas suggested by II-ESIs in seven cases (47%). In two of those patients (29%), the regions indicated by II-ESIs were not resected, resulting in poor surgical outcomes. ConclusionThis study demonstrates that the localization accuracy of II-ESI was comparable to ictal SPECT and the brain FDG-PET scan. II-ESI is a simple, noninvasive method for evaluating the epileptogenic zone and guiding iEEG planning in patients with MRI-negative epilepsy.

Obinutuzumab Can Be Administered as a 90-minute Short Duration Infusion in Patients With Previously Untreated Follicular Lymphoma: GAZELLE End of Induction Analysis.

Obinutuzumab Can Be Administered as a 90-minute Short Duration Infusion in Patients With Previously Untreated Follicular Lymphoma: GAZELLE End of Induction Analysis.