PET Scores Research Articles

P0136 The role of FDG PET/CT in the and identification of fibrosis related to Crohn’s disease

Abstract Background There is a constant search for non-invasive evaluation methods for the identification of fibrosis in patients treated for Crohn’s disease, since this condition can severely impact patients’ quality of life in the long run. While PET/CT is mostly used in oncological evaluation, it was previously proved that it can be useful in the evaluation of inflammation associated with Crohn’s disease activity, since segmental FDG uptake is proportional with immune cell infiltration of the bowel. However, it’s role in the detection of fibrosis needs further evaluation. Our aim was to prospectively evaluate the prognostic value of FDG/PET CT in the identification of fibrosis related to Crohn’s disease regarding global PET scores compared to other imaging techniques (i.e. MRI, CT), simple endoscopic score (SES-CD), CD Activity Index (CDAI) intraoperative findings and histological evaluation of resected bowel segment. Methods We prospectively evaluated our patients from in and outpatient care between October 2021 and October 2024 who underwent bowel segment resection due to stenosis that was identified at a follow-up colonoscopy. On PET-CT, we scored the FDG uptake in the small intestine and the 4 colon segments. Regions with increased FDG uptake were segmented with metabolically active volume (MAV), uncorrected maximal standardized uptake value (SUVmax), related to the SUVmax of the liver (as a reference for normal tissue activity) and uncorrected total lesion glycolysis (TLG). Results A total of 17 patients were selected, 11 (65 %) males and 6 (35 %) females, with a median age of 43 years (29-44). Ten patients (59 %) had Crohn’s disease affecting the small and large bowel, while in 3 (18 %) patients it affected only the small intestines and in 4 cases (23 %) it was localized solely on the large intestines. Seven (41 %) patients were bio naive, while 10 patients (59 %) received at least one biological therapy since their diagnosis. Five patients had a history of previous resection, from which three underwent endoscopic dilatation as well before the current surgery. In active disease, PET was more informative than endoscopy to access the extent of the inflammation, and small intestine involvement. FDG PET-CT proved to be statistically more efficient in the identification of affected bowel segments than MRI or colonoscopy. However, we could not find an association between FDG PET-CT scores and the presence of fibrosis in our patients. Conclusion FDG PET-CT is a non-invasive complementary method for the evaluation of the affected bowel segments in CD, however its role in the identification of fibrosis is still not evident. This needs further investigation and a larger number of patients.

Predictive biomarkers of response to tocilizumab in giant cell arteritis (GCA): correlations with imaging activity.

In the recent EULAR recommendations, ultrasound examination is now recommended as a first-line imaging test in all patients with suspected giant cell arteritis (GCA) and the axillary arteries should be included in the standard exam. As an alternative to ultrasound evaluation, cranial and extracranial arteries can be examined using FDG-PET or MRI. The aim of our study was to observe in a retrospective case series whether there is a correlation between biomarkers and imaging activity in a population of patients followed in real life with GCA treated with prednisone (PDN) and tocilizumab (TCZ). We retrospectively enrolled 68 patients with newly diagnosed GCA between January 2020 and September 2021, followed in real life, who were examined at the Rheumatology Unit of the San Giovanni di Dio Hospital, Florence, Italy. Patients were evaluated at T0-T3-T6-T12-T18-T24 for the following blood tests: ESR, CRP, fibrinogen, platelet count, serum amyloid A (SAA), IL-6, and circulating calprotectin (MRP). Ultrasound examination of the temporal arteries and axillary arteries was assessed at T0 within 7days of starting treatment with high-dose glucocorticoids and subsequently at T3-T6-T12-T18-T24. A scale from 0 to 3 with semi-quantitative tools (SUV max) was assessed at T0-T12-T24. The evaluation of the correlation coefficient between laboratory and imaging variables has shown that SAA and MRP have the most powerful correlation with the PET score (0.523 and 0.64), and MRP also has an excellent correlation coefficient with the Halo score (0.658). The evaluation of the ROC curves shows for a PET score 3 and SAA values higher than 26mg/L, sensitivity of 81.5% and specificity of 84.1%, and for a PET score 3 and MRP values higher than 2.3 mcg/mL, sensitivity of 100% and specificity of 76.8%. In this study, we demonstrated that SAA and MRP can be useful as promising tools to detect GCA activity. The study demonstrates a good correlation between the two biomarkers and the imaging activity evaluated by the Halo and PET scores.

PET/MRI in paediatric inflammatory bowel disease - a prospective accuracy study.

Cross-sectional imaging supplements endoscopy in detecting disease manifestations in inflammatory bowel diseases (IBD). This study aimed to evaluate the accuracy of PET/MRI in a paediatric population suspected of IBD. This prospective study consecutively included patients aged 8-17 years under diagnostic evaluation for IBD. Forty-three patients underwent a PET/MRI scan and subsequent ileocolonoscopy, of whom 26 patients diagnosed with IBD participated in a follow-up scan, hereof 19 with Crohn's disease (CD), five with Ulcerative colitis and two with unclassified IBD. The results of PET alone, MRI alone, and PET/MRI combined were compared to a reference standard of endoscopy and histopathology. Of the 208 intestinal segments analysed, 109 showed inflammation, and 99 had no inflammation. In the per-segment analysis PET had a sensitivity of 0.83 (95% CI 0.73-0.93), specificity of 0.59 (95% CI 0.47-0.71), and area under the receiver operating characteristic curve (AUROC) of 0.73 (95% CI 0.67-0.80). MRI had a sensitivity of 0.52 (95% CI 0.41-0.64), specificity 0.89 (95% CI 0.82-0.96), and AUROC of 0.72 (95% CI 0.66-0.77). PET/MRI had a sensitivity of 0.83 (95% CI 0.74-0.94), specificity of 0.57 (95% CI 0.44-0.69), and AUROC of 0.77 (95% CI 0.71-0.84). At follow-up, PET and MRI scores decreased, and the change in MRI was able to identify patients with a clinical response. The accuracy of the PET/MRI scan in detecting inflammation in the terminal ileum and colon was moderate and not superior to either modality alone. With technological advances and combined reading, PET/MRI may still be valuable in selected cases.

Pre-Randomization Predictors of Study Discontinuation in a Preclinical Alzheimer’s Disease Randomized Controlled Trial

BackgroundParticipant discontinuation from study treatment in a clinical trial can leave a trial underpowered, produce bias in statistical analysis, and limit interpretability of study results. Retaining participants in clinical trials for the full study duration is therefore as important as participant recruitment.ObjectiveThis analysis aims to identify associations of pre-randomization characteristics of participants with premature discontinuation during the blinded phase of the Anti-Amyloid treatment in Asymptomatic AD (A4) Study.DesignAll A4 trial randomized participants were classified as having prematurely discontinued study during the blinded period of the study for any reason (dropouts) or completed the blinded phase of the study on treatment (completers).SettingThe trial was conducted across 67 study sites in the United States, Canada, Japan and Australia through the global COVID-19 pandemic.ParticipantsThe sample consisted of all 1169 A4 trial randomized participants.MeasurementsPre-randomization demographic, clinical, amyloid PET and genetic predictors of study discontinuation were evaluated using a univariate generalized linear mixed model (GLMM), with discontinuation status as the binary outcome, each predictor as a fixed effect, and site as a random effect to account for differences among study sites in the trial. Characteristics significant at p<0.10 were then included in a multivariable GLMM.ResultsAmong randomized participants, 339 (29%) discontinued the study during the blinded period (median follow-up time in trial: 759 days). From the multivariable analysis, the two main predictors of study discontinuation were screening State-Trait Anxiety Inventory (STAI) scores (OR = 1.07 [95%CI = 1.02; 1.12]; p=0.002) and age (OR = 1.06 [95%CI = 1.03; 1.09]; p<0.001). Participants with a family history of dementia (OR = 0.75 [95%CI = 0.55; 1.01]; p=0.063) and APOE ε4 carriers (OR = 0.79 [95%CI = 0.6; 1.04]; p=0.094) were less likely to discontinue from the study, with the association being marginally significant. In these analyses, sex, race and ethnicity, cognitive scores and amyloid/tau PET scores were not associated with study dropout.ConclusionsIn the A4 trial, older participants and those with higher levels of anxiety at baseline as measured by the STAI were more likely to discontinue while those who had a family history of dementia or were APOE ε4 carriers were less likely to drop out. These findings have direct implications for future preclinical trial design and selection processes to identify those individuals at greatest risk of dropout and provide information to the study team to develop effective selection and retention strategies in AD prevention studies.

THE POTENTIAL BENEFITS OF COMPANION ROBOTIC PETS ON THE QUALITY OF LIFE AMONG COMMUNITY-DWELLING OLDER WOMEN

Abstract This project explores whether companion robotic pets improve mental well-being of community-dwelling older women with depression. Depression is a major mental health issue disproportionately impacting women due to lifelong experiences of sexism and limitations in education and employment. Aging exacerbates an already undervalued status, and feelings of powerlessness increase. Women thus experience double jeopardy from discrimination on both gender and age (Hooyman et al., 2017). This project will investigate the efficacy of companion robotic pets and will recommend plans to the local Office for Aging (OFA). Recruitment was done in collaboration with the local OFA, with mail-survey data collected from community-dwelling women over the age of 65. 38 participants were provided with a robotic pet after an initial screening. Following a one-group pretest posttest design, data from 31 participants were used to determine the impact of a robotic pet intervention on older women’s quality of life. Paired samples t-tests were used to compare means of the 15-item Geriatric Depression Scale (GDS), 10-item Geriatric Anxiety Scale (GAS), 6-item De Jong Loneliness Scale, and one physical health status question completed by 30 women. There was a significant average difference between before- and after-companion pet scores for depression (t29 = 6.597, p &amp;lt; 0.001), anxiety (t29 = 6.728, p &amp;lt; 0.001), loneliness (t29 = 6.462, p &amp;lt; 0.001) and physical health (t29 = - 3.496, p = 0.002). Results confirmed companion robotic pets improve mental health in older women with depression and anxiety. Moreover, they are helpful in improving loneliness and physical health.

Evaluation of Parkinson's disease early diagnosis using single-channel EEG features and auditory cognitive assessment.

Parkinson's disease (PD) often presents with subtle early signs, making diagnosis difficult. F-DOPA PET imaging provides a reliable measure of dopaminergic function and is a primary tool for early PD diagnosis. This study aims to evaluate the ability of machine-learning (ML) extracted EEG features to predict F-DOPA results and distinguish between PD and non-PD patients. These features, extracted using a single-channel EEG during an auditory cognitive assessment, include EEG feature A0 associated with cognitive load in healthy subjects, and EEG feature L1 associated with cognitive task differentiation. Participants in this study are comprised of cognitively healthy patients who had undergone an F-DOPA PET scan as a part of their standard care (n = 32), and cognitively healthy controls (n = 20). EEG data collected using the Neurosteer system during an auditory cognitive task, was decomposed using wavelet-packet analysis and machine learning methods for feature extraction. These features were used in a connectivity analysis that was applied in a similar manner to fMRI connectivity. A preliminary model that relies on the features and their connectivity was used to predict initially unrevealed F-DOPA test results. Then, generalized linear mixed models (LMM) were used to discern between PD and non-PD subjects based on EEG variables. The prediction model correctly classified patients with unrevealed scores as positive F-DOPA. EEG feature A0 and the Delta band revealed distinct activity patterns separating between study groups, with controls displaying higher activity than PD patients. In controls, EEG feature L1 showed variations between resting state and high-cognitive load, an effect lacking in PD patients. Our findings exhibit the potential of single-channel EEG technology in combination with an auditory cognitive assessment to distinguish positive from negative F-DOPA PET scores. This approach shows promise for early PD diagnosis. Additional studies are needed to further verify the utility of this tool as a potential biomarker for PD.

Longitudinal changes in hippocampal texture from healthy aging to Alzheimer's disease.

Early detection of Alzheimer's disease is essential to develop preventive treatment strategies. Detectible change in brain volume emerges relatively late in the pathogenic progression of disease, but microstructural changes caused by early neuropathology may cause subtle changes in the MR signal, quantifiable using texture analysis. Texture analysis quantifies spatial patterns in an image, such as smoothness, randomness and heterogeneity. We investigated whether the MRI texture of the hippocampus, an early site of Alzheimer's disease pathology, is sensitive to changes in brain microstructure before the onset of cognitive impairment. We also explored the longitudinal trajectories of hippocampal texture across the Alzheimer's continuum in relation to hippocampal volume and other biomarkers. Finally, we assessed the ability of texture to predict future cognitive decline, over and above hippocampal volume. Data were acquired from the Alzheimer's Disease Neuroimaging Initiative. Texture was calculated for bilateral hippocampi on 3T T1-weighted MRI scans. Two hundred and ninety-three texture features were reduced to five principal components that described 88% of total variance within cognitively unimpaired participants. We assessed cross-sectional differences in these texture components and hippocampal volume between four diagnostic groups: cognitively unimpaired amyloid-β- (n = 406); cognitively unimpaired amyloid-β+ (n = 213); mild cognitive impairment amyloid-β+ (n = 347); and Alzheimer's disease dementia amyloid-β+ (n = 202). To assess longitudinal texture change across the Alzheimer's continuum, we used a multivariate mixed-effects spline model to calculate a 'disease time' for all timepoints based on amyloid PET and cognitive scores. This was used as a scale on which to compare the trajectories of biomarkers, including volume and texture of the hippocampus. The trajectories were modelled in a subset of the data: cognitively unimpaired amyloid-β- (n = 345); cognitively unimpaired amyloid-β+ (n = 173); mild cognitive impairment amyloid-β+ (n = 301); and Alzheimer's disease dementia amyloid-β+ (n = 161). We identified a difference in texture component 4 at the earliest stage of Alzheimer's disease, between cognitively unimpaired amyloid-β- and cognitively unimpaired amyloid-β+ older adults (Cohen's d = 0.23, Padj = 0.014). Differences in additional texture components and hippocampal volume emerged later in the disease continuum alongside the onset of cognitive impairment (d = 0.30-1.22, Padj < 0.002). Longitudinal modelling of the texture trajectories revealed that, while most elements of texture developed over the course of the disease, noise reduced sensitivity for tracking individual textural change over time. Critically, however, texture provided additional information than was provided by volume alone to more accurately predict future cognitive change (d = 0.32-0.63, Padj < 0.0001). Our results support the use of texture as a measure of brain health, sensitive to Alzheimer's disease pathology, at a time when therapeutic intervention may be most effective.

Weight increases and decreases show distinct association with Alzheimer’s Disease in different age and APOE‐ε4 status

AbstractBackgroundHigh and low body mass index (BMI) may increase the risk of Alzheimer’s disease (AD) in mid‐life (age&lt;65) and late‐life (age≥65) respectively. However, it is still not fully understood about the associations of BMI changes with AD progression as well as how APOE‐ε4 allele modulates their relationships in mid‐life and late‐life. In this study, we aimed to determine how BMI changes and APOE‐ε4 allele relate to longitudinal β‐amyloid (Aβ) accumulation, tau aggregation, neurodegeneration and cognitive decline in mid‐life and late‐life.MethodWe examined 325 cognitively unimpaired and 391 mild cognitive impairment Alzheimer’s Disease Neuroimaging Initiative participants with longitudinal 18F‐florbetapir (FBP) Aβ PET and BMI measurements. Among of them, 486, 707 and 710 had longitudinal 18F‐fluorodeoxyglucos (FDG) PET, adjusted hippocampal volume (aHCV) and memory scores, and 246 participants had follow‐up 18F‐flortaucipir (FTP) tau PET data measured at a median of 5.5 years post baseline FBP scan. We investigated the associations of BMI slopes with longitudinal changes of AD typical summary cortical region FBP PET and FDG PET, aHCV and memory scores, and follow‐up Temporal‐metaROI FTP PET in different Aβ status (Aβ‐ and Aβ+), APOE‐ε4 status (carriers and non‐carriers), age (mid‐life and late‐life).ResultWe found faster BMI decreases accelerated the rates of Aβ accumulation (Fig.1D, standardized β (βstd) = ‐0.29, p = 0.002), hypometabolism (Fig.3D, βstd = 0.24, p = 0.03), hippocampal atrophy (Fig.3H, βstd = 0.29, p = 0.002), and memory decline (Fig.4D, βstd = 0.28, p = 0.005), and induced marginally higher follow‐up tau deposition (Fig.2D, βstd = ‐0.26, p = 0.09) in Aβ+ late‐life APOE‐ε4 non‐carriers but not in APOE‐ε4 carriers. In contrast, BMI increases were related to faster (Fig.1C, βstd = 0.80, p &lt; 0.001) rates of Aβ accumulation in Aβ+ mid‐life APOE‐ε4 carriers but not in APOE‐ε4 non‐carriers.ConclusionThese findings suggest that weight increase in mid‐life APOE‐ε4 carriers and weight loss in late‐life APOE‐ε4 non‐carriers are environmental risk factors of AD, highlighting the importance of tracking BMI data in Aβ+ individuals.

Diagnostic accuracy and validation of 18F-fluorodeoxyglucose positron emission tomography scores in a large cohort of patients with polymyalgia rheumatica.

BackgroundSeveral studies have shown that 18F-FDG PET may contribute to the diagnosis of polymyalgia rheumatica (PMR). Previously, we developed a composite PET score called the Leuven score, which was recently adapted to the more concise Leuven/Groningen score by van der Geest et al. The aim of this study is to validate and compare the diagnostic accuracy and cut-off points of both scores in a large cohort of PMR patients.MethodsPatients with a possible clinical diagnosis of PMR and a PET scan prior to the initiation of glucocorticoids between 2003 and 2020 were included retrospectively. The gold standard for the diagnosis of PMR was the judgment of two experienced clinicians after a follow-up of at least 6 months. FDG uptake was scored visually in 12 articular regions (scores 0–2) and a total skeletal score was calculated by summing the individual scores (maximum of 24 for the Leuven score and 14 for the Leuven/Groningen score). Receiver operating characteristic (ROC) analysis and the Youden index were used to determine the diagnostic accuracy and optimal cut-off points.ResultsA total of 162 patients with PMR and 83 control patients were included. Both PET scores showed high diagnostic accuracy in the ROC analysis (area under the curve 0.986 and 0.980, respectively). The Leuven Score provided a sensitivity of 91.4%, specificity of 97.6% and accuracy of 93.5% at its predefined cut-off point of 16. With the newly determined cut-off point of 12 the sensitivity was 98.8%, the specificity 95.2% and the accuracy 97.6%. The Leuven/Groningen score had a sensitivity, specificity and accuracy of 93.2%, 95.2%, and 93.9%, respectively, with the pre-specified cut-off point of 8, and 96.9%, 92.8%, and 95.5% with the optimal cut-off point of 7.ConclusionThe original Leuven score and the simplified Leuven/Groningen score both had excellent diagnostic accuracy. The latter may be easier to apply in clinical practice.

IDENTIFYING WOMEN WITH PSYCHOLOGICAL PROBLEMS DURING THE IN VITRO FERTILIZATION PROCESS: THE PSYCHOLOGICAL EVALUATION TEST (PET)

Especially strong or inadequate emotional reactions during in vitro fertilization (IVF) treatment may affect both the success of the treatment and later mental health. This study tested the possibility of using Psychological Evaluation Test for Infertile Couples (PET) scores to identify women with psychological problems during the IVF process, so that they can be offered psychological counseling. The sample comprised 158 women, all of whom were undergoing the IVF treatment at the time of the study, and 128 women who had at least one child conceived without difficulties. All of the respondents filled in a questionnaire concerning their emotional status and coping competencies, while the PET was given only to the respondents undergoing IVF. Respondents with higher PET scores (&gt; 30) have significantly higher Negative Affectivity and Shame in front of others, and lower Positive Affectivity and Coping competencies than the group with low PET scores (≤ 30) and women who conceived without difficulties. Respondents with lower PET scores do not significantly differ from women who conceived without difficulties. The results obtained suggest that the PET cut-off score &gt; 30 may be considered a reliable measure to identify women with psychological problems i.e., reaching scores of &gt; 30 can be taken as an indicator of the need for psychological support.

The Combined Interpretation of 68Ga-DOTATATE PET/CT and 18F-FDG PET/CT in Metastatic Gastroenteropancreatic Neuroendocrine Tumors: A Classification System With Prognostic Impact.

Gastroenteropancreatic neuroendocrine neoplasms (GEP NEN) are widely heterogeneous in their biological behavior, and predicting prognosis and optimal treatment strategies can be challenging. 68Ga-DOTATATE PET/CT is a sensitive imaging modality for well-differentiated NEN and indicates a favorable prognosis, whereas 18F-FDG PET/CT avidity indicates disease that is potentially more aggressive. There has been emerging interest in the combined interpretation of 68Ga-DOTATATE and 18F-FDG PET and its prognostic significance. We aimed to assess the prognostic utility of a classification system that incorporates the complex findings of 68Ga-DOTATATE and 18F-FDG PET interpreted side-by-side in patients with metastatic GEP NEN. We defined 3 68Ga-DOTATATE/18F-FDG "dual-tracer PET" groups: D1 (68Ga-DOTATATE positive/18F-FDG negative), D2 (68Ga-DOTATATE positive/18F-FDG positive), and D3 (68Ga-DOTATATE negative/18F-FDG positive). We retrospectively assessed the association between the dual-tracer PET classification and progression-free and overall survival (OS) using Kaplan-Meier analysis. Univariate and multivariate analyses were performed using the Cox proportional hazards model. Eighty-seven patients with metastatic GEP NEN and contemporaneous 68Ga-DOTATATE and 18F-FDG PET were included. The dual-tracer PET classification was an independent predictor of OS (multivariate P = 0.016) and also predicted progression-free survival (univariate P = 0.030). Other independent predictors of OS included chromogranin A and World Health Organization (WHO) grade. WHO grade was not associated with OS from the time of dual-tracer PET but was an independent predictor of OS from the date of histological diagnosis (multivariate P = 0.003). Our study demonstrates that a classification system combining the complex findings of 68Ga-DOTATATE and 18F-FDG PET is correlated with prognosis. Further research is needed to prospectively validate these findings and to explore whether dual-tracer PET scores may also be able to predict response to treatment.

Assessment of Takayasu arteritis in routine practice with PETVAS, an 18F-FDG PET quantitative scoring tool.

The aim of this study was to evaluate the value of the PET vascular activity score (PETVAS) during the follow-up of patients with Takayasu arteritis. Takayasu arteritis patients who underwent 18F-Fluorodeoxyglucose (FDG) PET imaging were evaluated retrospectively. In 8 patients both 1 and 2-h imagings were also performed prospectively. For PETVAS, 9 arterial areas were scored between 0-3 according to the FDG uptake. Forty-six images of 34 patients were evaluated. PETVAS was higher in patients with clinically active disease (p = 0.03) and in the C-reactive protein (CRP) elevated group among clinically inactive patients (p = 0.0015). PETVAS correlated with CRP (p = 0.003, r = 0.53) and erythrocyte sedimentation rate (p = 0.005, r = 0.41), whereas age, disease duration, immunosuppressive, and glucocorticoid (GC) treatments were not associated with PETVAS. First vs. 2nd-h PETVAS was similar in patients who had both 1st and 2nd h PET scans (p = 0.67). We observed higher PETVAS in patients with active disease and elevated acute phase reactants. Although scores in our study (performed at one-h) were lower compared to the original PETVAS study performed at two h, PETVAS seems to be a reliable tool to quantify FDG PET scores in routine practice.

Tau PET as a prognostic marker in preclinical and prodromal Alzheimer’s disease

AbstractBackgroundTau PET tracers have proven useful for diagnostic purposes, but their prognostic utility for predicting future cognitive changes over time is unclear. We aimed to examine the prognostic accuracy of [18F]flortaucipir and [18F]RO948 (tau) PET in individuals across the Alzheimer’s disease (AD) spectrum.MethodWe included 673 cognitively unimpaired individuals (CU, 277/673 amyloid‐β+), 443 participants with mild cognitive impairment (MCI, 279/443 amyloid‐β+) and 315 amyloid‐β+ participants with AD dementia. Amyloid‐β status was determined by PET and/or CSF. The participants underwent [18F]flortaucipir (n=1135, discovery cohort) or [18F]RO948 (n=296, replication cohort) PET, T1‐weighted MRI and repeated Mini‐Mental State Examination (MMSE). Baseline [18F]flortaucipir/[18F]RO948 PET standardized uptake value ratios (SUVR) within in a temporal region‐of‐interest (ROI)and an MRI‐based AD‐signature cortical thickness ROI were used to predict longitudinal changes of MMSE using linear mixed effect models. Additionally, we performed mediation analyses to test whether associations between baseline tau PET and cognitive change were mediated by baseline MRI measures, and examined whether age, sex and APOE genotype modified the association between baseline tau PET and cognitive change.ResultTau PET in a temporal ROI predicted changes in MMSE, and associations were stronger than for AD‐signature cortical thickness across all participants (R2: 0.34 vs 0.24, bootstrapped p‐value for difference: &lt;0.001), in amyloid‐β+ MCI (R2: 0.27 vs 0.13, p&lt;0.001) and in amyloid‐β+ CU (R2: 0.14 vs 0.04, p&lt;0.001, Figure‐1). AD signature cortical thickness only modestly mediated the association between tau PET and MMSE scores over time in amyloid‐β+ AD dementia (34.2%[95%CI: 16.8%‐59.0%] of the total effect, p&lt;0.001) and in amyloid‐β+ MCI (11.6%[0‐25.0%], p=0.044), but not in amyloid‐β+ CU (p=0.848, Figure‐2). Age (T=‐2.24, p=0.025), but not sex (T=0.95, p=0.341) or APOE genotype (T=1.32, p=0.188), modified the association between baseline tau PET and cognitive change, such that older individuals showed faster cognitive decline at similar tau PET levels (Figure‐3). Most results were replicated in the [18F]RO948 PET cohort.ConclusionTau PET is a promising tool for predicting future cognitive change and could support the prognostic process in preclinical(i.e. amyloid‐β+ CU) and prodromal (i.e. amyloid‐β+ MCI) stages of Alzheimer’s disease.

Assessment of Takayasu arteritis in routine practice with PETVAS, an 18F-FDG PET quantitative scoring tool

The aim of this study was to evaluate the value of PET Vascular Activity Score (PETVAS) during the follow-up of patients with Takayasu arteritis. Takayasu arteritis patients who underwent 18F-Fluorodeoxyglucose (FDG) PET imaging were evaluated retrospectively. In 8 patients both 1 and 2-hour imagings were also performed prospectively. For PETVAS, 9 arterial areas were scored between 0-3 according to the FDG uptake. Forty-six images of 34 patients were evaluated. PETVAS was higher in patients with clinically active disease (p=0.03) and in C-reactive protein (CRP) elevated group among clinically inactive patients (p=0.0015). PETVAS correlated with CRP (p=0.003, r=0.53) and erythrocyte sedimentation rate (p=0.005, r=0.41), whereas age, disease duration, immunosuppressive and glucocorticoid (GC) treatments were not associated with PETVAS. First vs 2nd-hour PETVAS was similar in patients who had both 1st and 2nd hour PET scans (p=0.67). We observed higher PETVAS in patients with active disease and elevated acute phase reactants. Although scores in our study (performed at one-hour) were lower compared to the original PETVAS study performed at two hours, PETVAS seems to be a reliable tool to quantify FDG PET scores in routine practice.

Enhanced Outcome Prediction in Early Stage Classical Hodgkin Lymphoma Using Pre-Treatment Biomarkers and Interim PET (BioPET); A Sub-Analysis of the UK NCRI RAPID Trial

Enhanced Outcome Prediction in Early Stage Classical Hodgkin Lymphoma Using Pre-Treatment Biomarkers and Interim PET (BioPET); A Sub-Analysis of the UK NCRI RAPID Trial

Metabolic scoring in autoimmune epilepsy-Should APE scores be modified?

We evaluate the potential utility of F-18 FDG-PET in addition to MRI in the diagnostic work-up of patients with autoimmune epilepsy (AE) and propose the inclusion of functional imaging in the antibody prevalence in epilepsy (APE) scoring system. This was a retrospective analysis in 60 patients, diagnosed and treated for AE, of whom 40 were antibody negative (presumed AE) and 20 were antibody positive (definitive AE). All patients had undergone a dedicated brain and whole body FDG-PET in the department of Nuclear Medicine. In the antibody negative group, MRI supported a diagnosis of AE in 23 patients. Both MRI and PET were indicative in 12 cases, and standalone PET was positive in 8. While MRI alone was diagnostic in 57% (23/40), the combined yield of both modalities was 77% (31/40). When PET scores were added to assign the APE score in MRI negative cases, average APE score was 5.4. In the antibody positive group, MRI supported the diagnosis of AE in 7 patients. Both MRI and PET were positive in 4 patients and standalone PET was positive in 5 patients. While MRI alone was diagnostic in 35% (7/20), the combined yield of both modalities was 60% (12/20). When PET scores were added to assign the APE score in MRI negative cases, average APE score was 6.1. The inclusion of metabolic information from PET distinctly improved (the sensitivity of) APE scores to predict autoimmune origin even in antibody negative cases. A larger prospective study of similar type could justify adoption of FDG-PET into the standard diagnostic procedure.

Relationship between 18F-FDG Uptake in the Oral Cavity, Recent Dental Treatments, and Oral Inflammation or Infection: A Retrospective Study of Patients with Suspected Endocarditis

[18F]-fluorodeoxyglucose positron emission tomography ([18F]FDG PET/CT) has proven to be a useful diagnostic tool in patients with suspected infective endocarditis (IE), but is conflicting in relation to dental procedures. Questions: Is there a correlation between [18F]FDG PET/CT findings, recent dental treatment, and an affected oral cavity? (2) Is there a correlation between infective endocarditis (IE), oral health status, and (extra)cardiac findings on [18F]FDG PET/CT? Methods: This retrospective study included 52 patients. All [18F]FDG PET/CT scans were examined visually by pattern recognition using a three-point scale and semi-quantified within the volume of interest (VOI) using SUVmax. Results: 19 patients were diagnosed with IE (group 1), 14 with possible IE (group 2), and 19 without IE based on the modified Duke criteria (group 3). No correlation was found between visual PET and SUVmax and sites of oral inflammation and infection. The visual PET scores and SUVmax were not significantly different between all groups. A significant difference in the SUVmax of the valve between all groups was observed. Conclusions: This study suggests that no correlation exists between the PET findings in the oral cavity and dental treatments or inflammation/infection. No correlation between IE, actual oral health status, and extra-cardiac findings was demonstrated. Additional research is needed to conclude whether [18F]FDG PET/CT imaging is a reliable diagnostic modality for oral inflammation and infection sites.

Reshaping the Amyloid Buildup Curve in Alzheimer Disease? Partial-Volume Effect Correction of Longitudinal Amyloid PET Data.

It was hypothesized that the brain β-amyloid buildup curve plateaus at an early symptomatic stage of Alzheimer disease (AD). Atrophy-related partial-volume effects (PVEs) degrade signal in hot-spot imaging techniques such as amyloid PET. The current study, a longitudinal analysis of amyloid-sensitive PET data, investigated the effect on the shape of the β-amyloid curve in AD when PVE correction (PVEC) is applied. Methods: We analyzed baseline and 2-y follow-up data for 216 symptomatic individuals on the AD continuum (positive amyloid status) enrolled in the Alzheimer's Disease Neuroimaging Initiative (17 with AD dementia and 199 with mild cognitive impairment), including 18F-florbetapir PET, MRI, and Mini Mental State Examination scores. For PVEC, the modified Müller-Gärtner method was performed. Results: Compared with non-PVE-corrected data, PVE-corrected data yielded significantly higher changes in regional and composite SUV ratio (SUVR) over time (P = 0.0002 for composite SUVRs). Longitudinal SUVR changes in relation to Mini Mental State Examination decreases showed a significantly higher slope for the regression line in the PVE-corrected than in the non-PVE-corrected PET data (F1 = 7.1, P = 0.008). Conclusion: These PVEC results indicate that the β-amyloid buildup curve does not plateau at an early symptomatic disease stage. A further evaluation of the impact of PVEC on the in vivo characterization of time-dependent AD pathology, including the reliable assessment and comparison of other amyloid tracers, is warranted.

Preoperative PET/CT score can predict complete resection in advanced epithelial ovarian cancer: a prospective study.

To assess the ability of preoperative positron emission tomography/computed tomography (PET/CT) scans to predict postoperative residual disease in advanced epithelial ovarian cancer (AEOC). Thirty-one women with suspected AEOC were enrolled in our prospective study before surgery from July 2016 to December 2017. Complete resection was determined as no residual disease (R0) after surgery. A PET/CT scan was obtained within 2 weeks before surgery in our hospital. The PET score was the sum of each score of the radiological criteria from Suidan's model. The correlations between the PET score and tumor burden and surgical complexity were evaluated by Pearson correlation analysis. T-test or Fisher's exact test was used to compare differences in the variables between the complete and incomplete resection groups. Receiver operating characteristic (ROC) curve analysis was performed to assess the accuracy of the PET score for predicting complete postoperative resection. The median [range] of PET score was 2 [0-8], and the PET score in 20 (65%) patients was less than 3. Complete resection was achieved in 11 (35.5%) patients after surgery, including 10 (90.91%) with low PET scores and only 1 (9.09%) with a high score. The PET score had a significant positive correlation with tumor burden [Eisenkop: r=0.603, P<0.001; peritoneal cancer index (PCI): r=0.522, P=0.003] but not with surgery complexity (Aletti: r=0.291, P=0.113). Patients with lower PET scores (P=0.046) and tumor burdens (Eisenkop: P=0.013; PCI: P=0.012) had higher rates of complete resection. The PET score and tumor burden were effective for predicting complete resection. The AUCPET, AUCEisenkop, and AUCPCI were 0.797 (95% CI: 0.633-0.961, P=0.01), 0.847 (95% CI: 0.707-0.988, P=0.003), and 0.811 (95% CI: 0.653-0.969, P=0.007), respectively. However, surgery complexity was not useful for assessing complete resection. The preoperative PET score can noninvasively reflect tumor burden and helps predict complete resection after surgery in AEOC patients.

Prognostic Value of Metabolic Information in Advanced Gastric Cancer Using Preoperative 18F-FDG PET/CT.

This study evaluated the usefulness of semiquantitative and volumetric PET parameters for predicting prognosis in patients with advanced gastric cancer (AGC). We enrolled 213 patients who underwent 18F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) prior to curative surgery for AGC. Maximum standardized uptake value (SUVmax) and tumor-to-liver uptake ratio (TLR) were measured in all patients. Metabolic tumor volume (MTV) and total lesion glycolysis were measured in volume-measurable patients. For further quantification of FDG uptake, we developed PET prognostic scores by combining SUVmax and MTV (1: low SUVmax/low MTV; 2: high SUVmax/low MTV; 3: high SUVmax/high MTV). Comparison of PET parameters between recurrence and non-recurrence groups was performed. Univariate and multivariate analyses for recurrence-free survival (RFS) and overall survival (OS) were subsequently performed. The recurrence rate was 32.4% (69/213 patients). Mean SUVmax and mean MTV of the recurrence group were significantly higher than those of the non-recurrence group (p = 0.026 and p = 0.025). TLR showed marginal significance (p = 0.051). In multivariate analysis for RFS including all patients, SUVmax (p = 0.022), TLR (p = 0.010), and PET score (p = 0.003) were independent prognostic factors. In post hoc analysis of PET score, significant differences in RFS were observed between PET scores 2 and 3 as well as scores 1 and 3. No significant difference in RFS was observed between scores 1 and 2. Only PET score was statistically significant for OS in univariate analysis. None of the PET parameters were statistically significant for OS in multivariate analysis. High SUVmax and high MTV of the primary tumor suggest a high risk of recurrence for AGC patients. Even if SUVmax is similar, the prognosis may vary depending on MTV. Combining PET parameters results in a better prediction for prognosis.