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PurposeTo develop a method of biologically guided deep learning for post-radiation 18FDG-PET image outcome prediction based on pre-radiation images and radiotherapy dose information.MethodsBased on the classic reaction-diffusion mechanism, a novel biological model was proposed using a partial differential equation that incorporates spatial radiation dose distribution as a patient-specific treatment information variable. A 7-layer encoder-decoder-based convolutional neural network (CNN) was designed and trained to learn the proposed biological model. As such, the model could generate post-radiation 18FDG-PET image outcome predictions with breakdown biological components for enhanced explainability. The proposed method was developed using 64 oropharyngeal patients with paired 18FDG-PET studies before and after 20-Gy delivery (2 Gy/day fraction) by intensity-modulated radiotherapy (IMRT). In a two-branch deep learning execution, the proposed CNN learns specific terms in the biological model from paired 18FDG-PET images and spatial dose distribution in one branch, and the biological model generates post-20-Gy 18FDG-PET image prediction in the other branch. As in 2D execution, 718/233/230 axial slices from 38/13/13 patients were used for training/validation/independent test. The prediction image results in test cases were compared with the ground-truth results quantitatively.ResultsThe proposed method successfully generated post-20-Gy 18FDG-PET image outcome prediction with breakdown illustrations of biological model components. Standardized uptake value (SUV) mean values in 18FDG high-uptake regions of predicted images (2.45 ± 0.25) were similar to ground-truth results (2.51 ± 0.33). In 2D-based Gamma analysis, the median/mean Gamma Index (

Predicting clinical response to repetitive transcranial magnetic stimulation (rTMS) in medication-resistant depression (MRD) has gained great importance in recent years. Mainly, the right subgenual anterior cingulate cortex (sgACC) functional connectivity has been put forward as biomarker in relation to rTMS clinical outcome. Even though the left and right sgACC may have different neurobiological functions, little is known about the possible lateralized predictive role of the sgACC in rTMS clinical outcome. In 43 right-handed antidepressant-free MRD patients, we applied a searchlight-based interregional covariance connectivity approach using the baseline 18FDG-PET scan—collected from two previous high-frequency (HF)-rTMS treatment studies delivering stimulation to the left dorsolateral prefrontal cortex (DLPFC)—and investigated whether unilateral or bilateral sgACC glucose metabolism at baseline would result in different predictive metabolic connectivity patterns. Regardless of sgACC lateralization, the weaker the sgACC seed-based baseline metabolic functional connections with the (left anterior) cerebellar areas, the significantly better the clinical outcome. However, the seed diameter seems to be crucial. Similar significant findings on sgACC metabolic connectivity with the left anterior cerebellum, also unrelated to sgACC lateralization, in relation to clinical outcome were observed when using the HCPex atlas. Although we could not substantiate that specifically right sgACC metabolic connectivity would predict HF-rTMS clinical outcome, our findings suggest considering the entire sgACC in functional connectivity predictions. Given that the interregional covariance connectivity results were significant only when using the Beck Depression Inventory (BDI-II) and not with the Hamilton Depression Rating Scale (HDRS), our sgACC metabolic connectivity observations also suggest the possible involvement of the (left) anterior cerebellum involved in higher-order cognitive processing as part of this predictive value. [ABSTRACT FROM AUTHOR]

Diagnosing suspected renal or hepatic infections in autosomal dominant polycystic kidney disease (ADPKD) is difficult. Although 18-fluorodeoxyglucose positron-emission tomography-computed tomography ( 18 F-FDG PET-CT) is recommended to aid in the diagnosis, there is no consensus about its diagnostic accuracy. We aimed to investigate its diagnostic performance. To further assess this, we performed a meta-analysis. A comprehensive literature search screening of PubMed/MEDLINE, Embase, and Cochrane library databases through February 2024 was performed. Pooled sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and C-reactive protein (CRP) were estimated using the random effects model. Heterogeneity between studies was estimated using Cochran Q and I2 statistics. A total of seven studies were included in the final analysis. The pooled sensitivity of 18 F-FDG PET-CT in diagnosing kidney and hepatic cyst infection was 82.6% (95% CI: 73.8-88.9; I2 16.9%), specificity was 77.6% (95% CI: 66.7-85.7; I2 15.6%), PPV was 79.4% (95% CI: 62.4-89.9; I2 62.6%), and NPV was 81.3% (95% CI: 72.7-87.7; I2 0%). The mean CRP was 244.2 mg/L (95% CI: 209.1-279.1; I2 66%). The results showed that  18 F-FDG PET-CT demonstrated excellent pooled diagnostic performance in diagnosing renal and hepatic cyst infections in ADPKD., Competing Interests: Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Chandramohan et al.)

Decreased anabolic androgen levels are followed by impaired brain energy support and sensing with loss of neural connectivity during physiological aging, providing a neurobiological basis for hormone supplementation. Here, we investigated whether nandrolone decanoate (ND) administration mediates hypothalamic AMPK activation and glucose metabolism, thus affecting metabolic connectivity in brain areas of adult and aged mice. Metabolic interconnected brain areas of rodents can be detected by positron emission tomography using 18FDG-mPET. Albino CF1 mice at 3 and 18 months of age were separated into 4 groups that received daily subcutaneous injections of either ND (15 mg/kg) or vehicle for 15 days. At the in vivo baseline and on the 14th day, brain 18FDG-microPET scans were performed. Hypothalamic pAMPKT172/AMPK protein levels were assessed, and basal mitochondrial respiratory states were evaluated in synaptosomes. A metabolic connectivity network between brain areas was estimated based on 18FDG uptake. We found that ND increased the pAMPKT172/AMPK ratio in both adult and aged mice but increased 18FDG uptake and mitochondrial basal respiration only in adult mice. Furthermore, ND triggered rearrangement in the metabolic connectivity of adult mice and aged mice compared to age-matched controls. Altogether, our findings suggest that ND promotes hypothalamic AMPK activation, and distinct glucose metabolism and metabolic connectivity rearrangements in the brains of adult and aged mice. [ABSTRACT FROM AUTHOR]

PurposeTo develop a method of biologically guided deep learning for post-radiation 18FDG-PET image outcome prediction based on pre-radiation images and radiotherapy dose information.MethodsBased on the classic reaction–diffusion mechanism, a novel biological model was proposed using a partial differential equation that incorporates spatial radiation dose distribution as a patient-specific treatment information variable. A 7-layer encoder–decoder-based convolutional neural network (CNN) was designed and trained to learn the proposed biological model. As such, the model could generate post-radiation 18FDG-PET image outcome predictions with breakdown biological components for enhanced explainability. The proposed method was developed using 64 oropharyngeal patients with paired 18FDG-PET studies before and after 20-Gy delivery (2 Gy/day fraction) by intensity-modulated radiotherapy (IMRT). In a two-branch deep learning execution, the proposed CNN learns specific terms in the biological model from paired 18FDG-PET images and spatial dose distribution in one branch, and the biological model generates post-20-Gy 18FDG-PET image prediction in the other branch. As in 2D execution, 718/233/230 axial slices from 38/13/13 patients were used for training/validation/independent test. The prediction image results in test cases were compared with the ground-truth results quantitatively.ResultsThe proposed method successfully generated post-20-Gy 18FDG-PET image outcome prediction with breakdown illustrations of biological model components. Standardized uptake value (SUV) mean values in 18FDG high-uptake regions of predicted images (2.45 ± 0.25) were similar to ground-truth results (2.51 ± 0.33). In 2D-based Gamma analysis, the median/mean Gamma Index (

A 56-year-old man complained progressive dyspnea, fatigue and fever for one month. His chest CT exhibited faint ground-glass opacities, and the levels of serum LDH and soluble interleukin 2 receptor were markedly elevated. Positron emission tomography (PET) showed high uptake of 18-fluoro deoxy glucose (18FDG) only on both lungs. We performed transbronchial lung biopsies (TBLB) for the diagnosis. After bronchoscopy, he had prolonged hypoxemia. Because defects of 99m-Technetium macroaggregated albumin (99mTc-MAA) in pulmonary blood flow scintigraphy were consistent with the distribution of 18FDG uptake in PET, we speculated that the presence of intravascular lymphoma (IVL) cells in the capillaries might have behaved like tumor embolism. We started rescue by prednisolone based on treatment of lymphoma. As a result, his hypoxemia was gradually improved. Histological findings in TBLB specimen showed that CD20+CD79+Bcl-2+c-myc+ lymphoma cells were localized to small vessel lumina in alveoli and bronchioles, and he was definitely diagnosed with lung intravascular large B cell lymphoma (IVLBCL). He was treated with complete cyclophosphamide, doxorubicin, vincristine, and prednisolone with rituximab (R–CHOP) in combination with intrathecal methotrexate injection. After eight cycles of R–CHOP and three times of intrathecal methotrexate, 18FDG uptake of PET on both lungs completely disappeared, achieving complete metabolic remission. We experienced a rare case of lung IVLBCL developed with respiratory failure successfully rescued by prednisolone prior to definite diagnosis.

Purpose: We sought to study the predictive value of the metabolic heterogeneous zone (HZ) as determined by 18Fluorodeoxyglucose (18FDG) positron emission tomography (PET) viability studies in ventricular tachycardia (VT) patients. Methods: PET studies utilizing 82Rubidium (82Rb) tracer for perfusion and 18FDG tracer for viability were analyzed using PMOD (PMOD Technologies) and further analyzed using 684‐segment plots. 18FDG uptake was normalized to the area with maximal perfusion on the rest 82Rb study. Metabolic scar, HZ, and healthy segments were defined with perfusion‐normalized 18FDG uptake between 0%–50%, 50%–70%, and >70%, respectively. Results: Thirty‐four VT patients (age, 63 ± 12 years) were evaluated with 18FDG‐PET viability study. Most (n = 31) patients underwent VT ablation. Patients were categorized to HZ < median versus HZ ≥ median based on a median HZ area size of 21.0 cm2. HZ size was significantly larger in the deceased group than the alive group (35.2 cm2 vs. 18.1 cm2, p =.01). Deaths were significantly higher in HZ ≥ 21 cm2 group than HZ < 21 cm2 group (58.8% vs. 11.8%, p =.005). Survival analysis showed significantly higher mortality in the HZ ≥ 21 cm2 group than the HZ < 21 cm2 group (HR = 4.1, 95% CI: 1.3–12.6, p =.016). In a multivariable analysis, HZ was found to be an independent predictor for all‐cause mortality (HR = 1.07, 95% CI: 1.02–1.12, p =.01) Conclusions: Increased HZ size of myocardium was associated with increased mortality. Metabolic HZ quantification may be of value in risk stratification and management of ischemic and nonischemic patients with VT. [ABSTRACT FROM AUTHOR]

Purpose: To quantify abnormal metabolism of diffuse gliomas using “aerobic glycolytic imaging” and investigate its biological correlation. Methods: All subjects underwent a pH-weighted amine chemical exchange saturation transfer spin-and-gradient-echo echoplanar imaging (CEST-SAGE-EPI) and dynamic susceptibility contrast perfusion MRI. Relative oxygen extraction fraction (rOEF) was estimated as the ratio of reversible transverse relaxation rate R2′ to normalized relative cerebral blood volume. An aerobic glycolytic index (AGI) was derived by the ratio of pH-weighted image contrast (MTRasym at 3.0 ppm) to rOEF. AGI was compared between different tumor types (N = 51, 30 IDH mutant and 21 IDH wild type). Metabolic MR parameters were correlated with 18F-FDG uptake (N = 8, IDH wild-type glioblastoma), expression of key glycolytic proteins using immunohistochemistry (N = 38 samples, 21 from IDH mutant and 17 from IDH wild type), and bioenergetics analysis on purified tumor cells (N = 7, IDH wild-type high grade). Results: AGI was significantly lower in IDH mutant than wild-type gliomas (0.48 ± 0.48 vs. 0.70 ± 0.48; P = 0.03). AGI was strongly correlated with 18F-FDG uptake both in non-enhancing tumor (Spearman, ρ = 0.81; P = 0.01) and enhancing tumor (ρ = 0.81; P = 0.01). AGI was significantly correlated with glucose transporter 3 (ρ = 0.71; P = 0.004) and hexokinase 2 (ρ = 0.73; P = 0.003) in IDH wild-type glioma, and monocarboxylate transporter 1 (ρ = 0.59; P = 0.009) in IDH mutant glioma. Additionally, a significant correlation was found between AGI derived from bioenergetics analysis and that estimated from MRI (ρ = 0.79; P = 0.04). Conclusion: AGI derived from molecular MRI was correlated with glucose uptake (18F-FDG and glucose transporter 3/hexokinase 2) and cellular AGI in IDH wild-type gliomas, whereas AGI in IDH mutant gliomas appeared associated with monocarboxylate transporter density.

Abstract Background Doxorubicin (DOX)-based chemotherapy for Hodgkin lymphoma (HL) yields excellent disease-free survival, but poses a substantial risk of subsequent left ventricular (LV) dysfunction and heart failure, typically with delayed onset. At the cellular level, this cardiotoxicity includes deranged cardiac glucose metabolism. Methods By reviewing the hospital records from January 2008 through December 2016, we selected HL patients meeting the following criteria: ≥ 18 year-old; first-line DOX-containing chemotherapy; no diabetes and apparent cardiovascular disease; 18-fluoro-deoxyglucose positron emission tomography (18FDG-PET) scans before treatment (PETSTAGING), after 2 cycles (PETINTERIM) and at the end of treatment (PETEOT); at least one echocardiography ≥ 6 months after chemotherapy completion (ECHOPOST). We then evaluated the changes in LV 18FDG standardized uptake values (SUV) during the course of DOX therapy, and the relationship between LV-SUV and LV ejection fraction (LVEF), as calculated from the LV diameters in the echocardiography reports with the Teicholz formula. Results Forty-three patients (35 ± 13 year-old, 58% males) were included in the study, with 26 (60%) also having a baseline echocardiography available (ECHOPRE). LV-SUV gradually increased from PETSTAGING (log-transformed mean 0.20 ± 0.27) to PETINTERIM (0.27 ± 0.35) to PETEOT (0.30 ± 0.41; P for trend

Corticobasal syndrome (CBS) is a neuropathologically heterogeneous entity. The use of cerebrospinal fluid and amyloid biomarkers enables detection of underlying Alzheimer's disease (AD) pathology. We thus compared clinical, eye movement, and 18FDG-PET imaging characteristics in CBS in two groups of patients divided according to their amyloid biomarkers profile. Fourteen patients presenting with CBS and amyloidosis (CBS-A+) were compared with 16 CBS patients without amyloidosis (CBS-A-). The two groups showed similar motor abnormalities (parkinsonism, dystonia) and global cognitive functions. Unlike CBS-A+ patients who displayed more posterior cortical abnormalities, CBS-A- patients demonstrated more anterior cortical and brain stem dysfunctions on the basis of neuropsychological testing, study of saccade velocities and brain hypometabolism areas on 18FDG-PET. Interestingly, Dopamine Transporter SPECT imaging showed similar levels of dopaminergic degeneration in both groups. These findings confirm common and distinct brain abnormalities between the different neurodegenerative diseases that result in CBS. We demonstrate the importance of a multidisciplinary approach to improve diagnosis in vivo in particular on oculomotor examination. [ABSTRACT FROM AUTHOR]

Objective: It is a well-known fact that positron emission tomography (PET) is an effective tool in the assessment of thyroid focal lesions, however only few studies so far have investigated its role in monitoring of autoimmune thyroid diseases (AITDs). The aim of this study is to assess if PET scan may be useful for the assessment of the thyroid gland in patients with an AITD—Hashimoto's thyroiditis.Methods: We evaluated twenty subjects with diagnosed Hashimoto's thyroiditis (proven by presence of elevated thyroid antibodies level and by thyroid imaging). The maximum standardized uptake value (SUV-max) of the thyroid parenchyma was measured using 18F-FDG-PET/CT. Control group consisted of patients who have been in carcinoma remission for other reasons than thyroid cancer and who had been investigated by PET scan to exclude carcinoma recurrence.All control group subjects had their thyroid glands intact, none of them had a medical history of thyroid disease including thyroid nodules. AITDs had been excluded in all control group subjects. STATISTICA 13.1 software was used for statistical analysis.Results: Results: The SUV-max was significantly higher in patients with an AITD than in healthy subjects (median SUV-max 3.94 vs. 1.95; p = 0.005).Conclusions:18F-FDG-PET/CT scan may differentiate normal thyroid parenchyma from the diffused inflammatory changes of the thyroid gland in patients with AITDs. However, the researchers must be continued.

Objective: Previous studies evaluating neurophysiological correlates of long-term meditation are constrained by some methodological limitations. The objective of this study was to measure changes in the regional cerebral glucose metabolism during meditation using a novel methodological approach. Design: The present study was a part of a larger, nonrandomized, single-center open-label study. Setting/location: The study was conducted at the Department of Physiology and Department of Nuclear Medicine and Positron Emission Tomography. A dedicated place was set up as a yoga room, away from the positron emission tomography (PET) scanning room in the Department of Nuclear Medicine and Positron Emission Tomography, where meditators performed meditation in a peaceful environment in a sitting posture with eyes closed. The electroencephalography (EEG) was recorded to affirm the meditation objectively. Subjects: Twenty-four sets of PET scans were obtained at 2 different occasions (baseline and postmeditation within 40 min of 18FDG [18fluorodeoxyglucose] injection) from 12 apparently healthy, male, right-handed long-term meditators practicing Preksha meditation (since >5 years, at least 5 days a week) who were recruited from a well-established meditation center in Delhi. Outcome measures: Changes in the regional cerebral glucose metabolism during meditation versus baseline. Results: Regional cluster analysis showed significantly activated well-defined areas of fronto-parieto-temporal regions of the right versus left hemisphere during meditation. Interestingly, right homolog of Broca's area and right lentiform nucleus were hyperactive during meditation in all the meditators. Conclusions: Long-term meditation might potentially enhance the explicit functions of specific parts of the right hemisphere, possibly due to neuroplastic changes in the brain. Importantly, results of the current study are encouraging and show a novel methodological approach to acquire 18FDG PET/CT (computed tomography) images. The study was registered at Clinical Trial Registry India (CTRI), CTRI/2009/091/000727. [ABSTRACT FROM AUTHOR]

Background: The C9orf72 pathogenetic GGGGCC hexanucleotide repeat expansion is one of the most common causes of Frontotemporal Dementia (FTD), and early identification of this mutation is crucial for clinical and prognostic outcome. Although promising preclinical studies tried to evaluate the efficacy of biomarkers to identify C9orf72 expansion carriers, they have not been adequately assessed in humans. Aim: To identify clinical, neuroimaging, and biological features that could be used to identify FTD subjects eligible to genetic testing. Methods: This is a retrospective, case‐control study of clinical, neuropsycological, biological, and neuroimaging data of C9orf72 expansion carriers compared with non‐mutated FTD patients. Neurofilament light chain was evaluated by Quanterix Simoa essay. Results: The study revealed a set of peculiar characteristics in patients with C9orf72 expansion, compared with not expanded, as: lower age at onset, higher number of familial form and affected relatives, higher FTD‐MND symptoms, frequent behavioral and motor disorders at onset, higher incidence of dysphagia, lower mnesic deficits and higher rate of "Average" and "Rapid" progression of the disease. Neuroimaging data reveled that C9orf72 subgroup patients showed a higher hypometabolism of the frontal lobes involving both cortical and subcortical regions. Moreover, in symptomatic C9orf72 patients, NfL concentration was strongly elevated compared with presymptomatic carriers, increasing after 1 year of follow‐up. Conclusion: The metabolic signature combined with the clinical features could be a helpful tool to direct the genetic counseling. We confirmed that serum NfL evaluation could be a valid biomarker to monitor the disease severity and progression. [ABSTRACT FROM AUTHOR]

Purpose: Recently, a new Bayesian Penalized Likelihood (BPL) Reconstruction Algorithm was introduced by GE Healthcare, Q.Clear; it promises to provide better PET image resolution compared to the widely used Ordered Subset Expectation Maximization (OSEM). The aim of this study is to compare the performance of these two algorithms on several types of findings, in terms of image quality, lesion detectability, sensitivity, and specificity. Methods: Between September 6th 2017 and July 31st 2018, 663 whole body 18F-FDG PET/CT scans were performed at the Nuclear Medicine Department of S. Martino Hospital (Belluno, Italy). Based on the availability of clinical/radiological follow-up data, 240 scans were retrospectively reviewed. For each scan, a hypermetabolic finding was selected, reporting both for OSEM and Q.Clear: SUVmax and SUVmean values of the finding, the liver and the background close to the finding; size of the finding; percentage variations of SUVmax and SUVmean. Each finding was subsequently correlated with clinical and radiological follow-up, to define its benign/malignant nature. Results: Overall, Q.Clear improved the SUV values in each scan, especially in small findings (< 10 mm), high SUVmax values (≥ 10), and medium/low backgrounds. Furthermore, Q.Clear amplifies the signal of hypermetabolic findings without modifying the background signal, which leads to an increase in signal-to-noise ratio, improving overall image quality. Finally, Q.Clear did not affect PET sensitivity or specificity, in terms of number of reported findings and characterization of their nature. Conclusions: Q.Clear is an iterative algorithm that improves significantly the quality of PET images compared to OSEM, increasing the SUVmax of findings (in particular for small findings) and the signal-to-noise ratio. However, due to the intrinsic characteristics of this algorithm, it will be necessary to adapt and/or modify the current interpretative criteria based of quantitative evaluation, to avoid an overestimation of the disease burden. [ABSTRACT FROM AUTHOR]

Objective: It is a well-known fact that positron emission tomography (PET) is an effective tool in the assessment of thyroid focal lesions, however only few studies so far have investigated its role in monitoring of autoimmune thyroid diseases (AITDs). The aim of this study is to assess if PET scan may be useful for the assessment of the thyroid gland in patients with an AITD—Hashimoto's thyroiditis. Methods: We evaluated twenty subjects with diagnosed Hashimoto's thyroiditis (proven by presence of elevated thyroid antibodies level and by thyroid imaging). The maximum standardized uptake value (SUV-max) of the thyroid parenchyma was measured using 18F-FDG-PET/CT. Control group consisted of patients who have been in carcinoma remission for other reasons than thyroid cancer and who had been investigated by PET scan to exclude carcinoma recurrence. All control group subjects had their thyroid glands intact, none of them had a medical history of thyroid disease including thyroid nodules. AITDs had been excluded in all control group subjects. STATISTICA 13.1 software was used for statistical analysis. Results: Results: The SUV-max was significantly higher in patients with an AITD than in healthy subjects (median SUV-max 3.94 vs. 1.95; p = 0.005). Conclusions: 18F-FDG-PET/CT scan may differentiate normal thyroid parenchyma from the diffused inflammatory changes of the thyroid gland in patients with AITDs. However, the researchers must be continued. [ABSTRACT FROM AUTHOR]

Purpose: Magnetic resonance imaging (MRI) and positron emission tomography (PET) with 18F-fluorodeoxyglucose (18FDG) are valuable tools for evaluating hippocampal sclerosis (HS); however, bias may arise during visual analyses. The aim of this study was to evaluate and compare MRI and PET post-processing techniques, automated quantitative hippocampal volume (Q-volume), and fluid-attenuated inversion-recovery (FLAIR) signal (Q-FLAIR) and glucose metabolism (Q-PET) analyses in patients with HS.Methods: We collected MRI and 18FDG-PET images from 54 patients with HS and 22 healthy controls and independently performed conventional visual analyses (CVA) of PET (CVA-PET) and MRI (CVA-MRI) images. During the subsequent quantitative analyses, the hippocampus was segmented from the 3D T1 image, and the mean volumetric, FLAIR intensity and standardized uptake value ratio (SUVR) values of the left and right hippocampus were assessed in each subject. Threshold confidence levels calculated from the mean volumetric, FLAIR intensity and SUVR values of the controls were used to identify healthy subjects or subjects with HS. The performance of the three methods was assessed using receiver operating characteristic (ROC) curves, and the detection rates of CVA-MRI, CVA-PET, Q-volume, Q-FLAIR, and Q-PET were statistically compared.Results: The areas under the curves (AUCs) for the Q-volume, Q-FLAIR, and Q-PET ROC analyses were 0.88, 0.41, and 0.98, which suggested a diagnostic method with moderate, poor, and high accuracy, respectively. Although Q-PET had the highest detection rate among the two CVA methods and three quantitative methods, the difference between Q-volume and Q-PET did not reach statistical significance. Regarding the HS subtypes, CVA-MRI, CVA-PET, Q-volume, and Q-PET had similar detection rates for type 1 HS, and Q-PET was the most sensitive method for detecting types 2 and 3 HS.Conclusions: In MRI or 18FDG-PET images that have been visually assessed by experts, the quantification of hippocampal volume or glucose uptake can increase the detection of HS and appear to be additional valuable diagnostic tools for evaluating patients with epilepsy who are suspected of having HS.

Purpose: Magnetic resonance imaging (MRI) and positron emission tomography (PET) with 18F-fluorodeoxyglucose (18FDG) are valuable tools for evaluating hippocampal sclerosis (HS); however, bias may arise during visual analyses. The aim of this study was to evaluate and compare MRI and PET post-processing techniques, automated quantitative hippocampal volume (Q-volume), and fluid-attenuated inversion-recovery (FLAIR) signal (Q-FLAIR) and glucose metabolism (Q-PET) analyses in patients with HS. Methods: We collected MRI and 18FDG-PET images from 54 patients with HS and 22 healthy controls and independently performed conventional visual analyses (CVA) of PET (CVA-PET) and MRI (CVA-MRI) images. During the subsequent quantitative analyses, the hippocampus was segmented from the 3D T1 image, and the mean volumetric, FLAIR intensity and standardized uptake value ratio (SUVR) values of the left and right hippocampus were assessed in each subject. Threshold confidence levels calculated from the mean volumetric, FLAIR intensity and SUVR values of the controls were used to identify healthy subjects or subjects with HS. The performance of the three methods was assessed using receiver operating characteristic (ROC) curves, and the detection rates of CVA-MRI, CVA-PET, Q-volume, Q-FLAIR, and Q-PET were statistically compared. Results: The areas under the curves (AUCs) for the Q-volume, Q-FLAIR, and Q-PET ROC analyses were 0.88, 0.41, and 0.98, which suggested a diagnostic method with moderate, poor, and high accuracy, respectively. Although Q-PET had the highest detection rate among the two CVA methods and three quantitative methods, the difference between Q-volume and Q-PET did not reach statistical significance. Regarding the HS subtypes, CVA-MRI, CVA-PET, Q-volume, and Q-PET had similar detection rates for type 1 HS, and Q-PET was the most sensitive method for detecting types 2 and 3 HS. Conclusions: In MRI or 18FDG-PET images that have been visually assessed by experts, the quantification of hippocampal volume or glucose uptake can increase the detection of HS and appear to be additional valuable diagnostic tools for evaluating patients with epilepsy who are suspected of having HS. [ABSTRACT FROM AUTHOR]

Abstract The possible hemispheric specialization of the basal ganglia during emotional prosody (i.e., vocal emotion) processing has still to be elucidated. Coupled with affective measures and neuroimaging, Parkinson's disease offers a unique opportunity to study this question, on account of its characteristically asymmetric striatal dysfunction, which translates into predominantly contralateral motor symptoms. We investigated the cerebral metabolic bases of emotional prosody recognition in patients with Parkinson's disease with left- versus right-lateralized motor symptoms, postulating that patients with greater right hemispheric brain dysfunction have a specific impairment that correlates with the metabolic modification of a brain network known to be involved in emotional prosody. A total of 38 patients performed a validated emotional prosody recognition task and underwent a resting-state F-18 fluorodeoxyglucose PET scan, as well as clinical, motor, neuropsychological, and psychiatric assessments. Patients' performances were compared with those of 45 healthy controls. As expected, vocal emotion recognition was significantly poorer among patients with left-sided motor symptoms than among both right-sided patients and controls. There was no significant difference between right-sided patients and controls. This effect was observed for both the total score and the happiness subscore. Interestingly, regressions showed that the greater the emotional misattribution, the greater the patients' age and asymmetric motor symptom severity. Finally, at the metabolic level, positive correlations were found between the happiness recognition subscore and the metabolism of the right orbitofrontal cortex in patients with left-sided motor symptoms. A right orbitofrontal-basal ganglia coupling seems to be specifically involved in the vocal emotion recognition deficit observed in Parkinson's disease. The asymmetry of motor symptoms is thus an important clinical factor, in that it may influence the presence or severity of affective disorders in Parkinson's disease. Graphical abstract fx1 Highlights • We explored the impact of lateralized motor symptoms on vocal emotion in PD. • Only left -lateralized PD patients presented a vocal emotion deficit. • This deficit correlated with glucose metabolism in the right orbito-frontal cortex. • This suggests a specific role of right fronto-striatal network in vocal emotion. • Brain hemispheric specialization in emotional prosody is discussed. [ABSTRACT FROM AUTHOR]

Background: When the results of electroencephalography (EEG), magnetic resonance imaging (MRI), and seizure semiology are discordant or no structural lesion is evident on MRI, single-photon emission computed tomography (SPECT) and positron emission tomography (PET) are important examinations for lateralization or localization of epileptic regions. We hypothesized that the concordance between interictal 2-[18F]fluoro-2-deoxy-D-glucose (18FDG)-PET and iomazenil (IMZ)-SPECT could suggest the epileptogenic lobe in patients with non-lesional findings on MRI.Method: Fifty-nine patients (31 females, 28 males; mean age, 29 years; median age, 27 years; range, 7-56 years) underwent subdural electrode implantation followed by focus resection. All patients underwent 18FDG-PET, IMZ-SPECT, and focus resection surgery. Follow-up was continued for ≥ 2 years. We evaluated surgical outcomes as seizure-free or not and analyzed correlations between outcomes and concordances of low-uptake lobes on PET, SPECT, or both PET and SPECT to the resection lobes. We used uni- and multivariate logistic regression analyses.Results: In univariate analyses, all three concordances correlated significantly with seizure-free outcomes (PET, p = 0.017; SPECT, p = 0.030; both PET and SPECT, p = 0.006). In multivariate analysis, concordance between resection and low-uptake lobes in both PET and SPECT correlated significantly with seizure-free outcomes (p = 0.004). The odds ratio was 6.0.Conclusion: Concordance between interictal 18FDG-PET and IMZ-SPECT suggested that the epileptogenic lobe is six times better than each examination alone among patients with non-lesional findings on MRI. IMZ-SPECT and 18FDG-PET are complementary examinations in the assessment of localization-related epilepsy. [ABSTRACT FROM AUTHOR]

• There is acute haematologic toxicity during chemo-radio treatment of anal cancer. • It can be reduced sparing active pelvic bone marrow for radiotherapy. • 18FDGPET is reference method for identifying active pelvic bone marrow. • Machine learning approach was applied to computed tomography (CT) for this purpose. • A total of 40 patients were collected with good overlap for 2 out of the 3 regions. Different methods are available to identify haematopoietically active bone marrow (ActBM). However, their use can be challenging for radiotherapy routine treatments, since they require specific equipment and dedicated time. A machine learning (ML) approach, based on radiomic features as inputs to three different classifiers, was applied to computed tomography (CT) images to identify haematopoietically active bone marrow in anal cancer patients. A total of 40 patients was assigned to the construction set (training set + test set). Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography (18FDG-PET) images were used to detect the active part of the pelvic bone marrow (ActPBM) and stored as ground-truth for three subregions: iliac, lower pelvis and lumbosacral bone marrow (ActIBM, ActLPBM, ActLSBM). Three parameters were used for the correspondence analyses between 18FDG-PET and ML classifiers: DICE index, Precision and Recall. For the 40-patient cohort, median values [min; max] of the Dice index were 0.69 [0.20; 0.84], 0.76 [0.25; 0.89], and 0.36 [0.15; 0.67] for ActIBM, ActLSBM, and ActLPBM, respectively. The Precision/Recall (P/R) ratio median value for the ActLPBM structure was 0.59 [0.20; 1.84] (over segmentation), while for the other two subregions the P/R ratio median has values of 1.249 [0.43; 4.15] for ActIBM and 1.093 [0.24; 1.91] for ActLSBM (under segmentation). A satisfactory degree of overlap compared to 18FDG-PET was found for 2 out of the 3 subregions within pelvic bones. Further optimization and generalization of the process is required before clinical implementation. [ABSTRACT FROM AUTHOR]

Objective: Although glucocorticoids are effective for patients with IgG4-related disease, the treatment has not yet been standardized. Therefore, the treatment strategy should be established. Patients and methods: Patients who fulfilled the comprehensive diagnostic criteria for definite IgG4- related disease were started on prednisolone (0.6mg/kg body weight) with the dose reduced every two weeks. The subsequent maintenance dose and need for prednisolone were determined for individual patients. The primary endpoint was the complete remission (CR) rate at one year. Secondary endpoints included overall response rate (ORR), the maintenance dose, the relapse rate, and adverse events. Results: This study enrolled 61 patients. After clinicopathological review, three patients were excluded, and one, 13, and 44 patients were diagnosed with probable, possible, and definite IgG4-related disease, respectively. Of the 44 patients with definite IgG4-RD, 29 (65.9%) achieved CR, and the ORR was 93.2%. No patient was refractory to primary treatment. The most frequent adverse events were glucose intolerance. Six patients relapsed. Conclusions: Glucocorticoid treatment is usually effective for patients with IgG4-RD, and we should examine the possibility of other disorders when a patient is glucocorticoid refractory. Some patients are misdiagnosed, making central clinicopathological review of diagnosis very important in conducting clinical studies. [ABSTRACT FROM AUTHOR]

Objective: To assess the predictive and prognostic value of progressive metabolic disease (PMD) by the use of early 18Fluorodeoxyglucose positron emission tomography (18FDG-PET) in patients with clinical stage IV non-small cell lung cancer (NSCLC) treated with first-line chemotherapy. Methods: An 18FDG-PET performed following the first cycle of chemotherapy (PET-1) was compared with a pretreatment 18FDG-PET (PET-0) and a computed tomography (CT) scan after the third cycle (CT-3). The primary endpoint was the positive predictive value (PPV) of PMD. Secondary endpoints included the prognostic value of PMD. Results: Eleven of 38 patients (29%) had a PMD by PET-1, and 15 (39%), including all patients with a PMD, experienced a progressive disease by CT-3. The PPV of PMD was 100% according to both the European Organization for Research and Treatment of Cancer (EORTC) criteria and the PET Response Criteria In Solid Tumors (PERCIST) (p value for both, <0.0001). Patients with a PMD by PET-1 had a median overall survival of 7.0 months versus 14.0 months for those without a PMD (p = 0.04, according to the EORTC criteria). Conclusions: Early 18FDG-PET assessment deserves further investigation for the identification of NSCLC patients who do not benefit from first-line chemotherapy. [ABSTRACT FROM AUTHOR]

The human brain appears organized in compartments characterized by seemingly specific functional purposes on many spatial scales. A complementary functional state binds information from specialized districts to return what is called integrated information. This fundamental network dynamics undergoes to severe disarrays in diverse degenerative conditions such as Alzheimer's Diseases (AD). The AD represents a multifarious syndrome characterized by structural, functional and metabolic landmarks. In particular, in the early stages of AD, adaptive functional modifications of the brain networks mislead initial diagnoses because cognitive abilities may result indiscernible from normal subjects. As a matter of facts, current measures of functional integration fail to catch significant differences among normal, mild cognitive impairment (MCI) and even AD subjects. The aim of this work is to introduce a new topological feature called Compression Flow (CF) to finely estimate the extent of the functional integration in the brain networks. The method uses a Monte Carlo-like estimation of the information integration flows returning the compression ratio between the size of the injected information and the size of the condensed information within the network. We analyzed the resting state connectomes of 75 subjects of the Alzheimer's Disease Neuroimaging Initiative 2 (ADNI) repository. Our analyses are focused on the 18FGD-PET and functional MRI (fMRI) acquisitions in several clinical screening conditions. Results indicated that CF effectively discriminate MCI, AD and normal subjects by showing a significant decrease of the functional integration in the AD and MCI brain connectomes. This result did not emerge by using a set of common complex network statistics. Furthermore, CF was best correlated with individual clinical scoring scales. In conclusion, we presented a novel measure to quantify the functional integration that resulted efficient to discriminate different stages of dementia and to track the individual progression of the impairments prospecting a proficient usage in a wide range of pathophysiological and physiological studies as well.

The human brain appears organized in compartments characterized by seemingly specific functional purposes on many spatial scales. A complementary functional state binds information from specialized districts to return what is called integrated information. These fundamental network dynamics undergoes to severe disarrays in diverse degenerative conditions such as Alzheimer’s Diseases (AD). The AD represents a multifarious syndrome characterized by structural, functional, and metabolic landmarks. In particular, in the early stages of AD, adaptive functional modifications of the brain networks mislead initial diagnoses because cognitive abilities may result indiscernible from normal subjects. As a matter of facts, current measures of functional integration fail to catch significant differences among normal, mild cognitive impairment (MCI) and even AD subjects. The aim of this work is to introduce a new topological feature called Compression Flow (CF) to finely estimate the extent of the functional integration in the brain networks. The method uses a Monte Carlo-like estimation of the information integration flows returning the compression ratio between the size of the injected information and the size of the condensed information within the network. We analyzed the resting state connectomes of 75 subjects of the Alzheimer’s Disease Neuroimaging Initiative 2 (ADNI) repository. Our analyses are focused on the 18FGD-PET and functional MRI (fMRI) acquisitions in several clinical screening conditions. Results indicated that CF effectively discriminate MCI, AD and normal subjects by showing a significant decrease of the functional integration in the AD and MCI brain connectomes. This result did not emerge by using a set of common complex network statistics. Furthermore, CF was best correlated with individual clinical scoring scales. In conclusion, we presented a novel measure to quantify the functional integration that resulted efficient to discriminate different stages of dementia and to track the individual progression of the impairments prospecting a proficient usage in a wide range of pathophysiological and physiological studies as well. [ABSTRACT FROM AUTHOR]

Anhedonia is a cardinal symptom of major depression and is often refractory to standard treatment, yet no approved medication for this specific symptom exists. In this exploratory re-analysis, we assessed whether administration of rapid-acting antidepressant ketamine was associated specifically with reduced anhedonia in medication-free treatment-refractory patients with major depressive disorder in an open-label investigation. Additionally, participants received either oral riluzole or placebo daily beginning 4 hours post-infusion. A subgroup of patients underwent fluorodeoxyglucose positron emission tomography scans at baseline (1–3 days pre-infusion) and 2 hours post-ketamine infusion. Anhedonia rapidly decreased following a single ketamine infusion; this was sustained for up to three days, but was not altered by riluzole. Reduced anhedonia correlated with increased glucose metabolism in the hippocampus and dorsal anterior cingulate cortex (dACC) and decreased metabolism in the inferior frontal gyrus and orbitofrontal cortex (OFC). The tentative relationship between change in anhedonia and glucose metabolism remained significant in dACC and OFC, and at trend level in the hippocampus, a result not anticipated, when controlling for change in total depression score. Results, however, remain tenuous due to the lack of a placebo control for ketamine. In addition to alleviating overall depressive symptoms, ketamine could possess anti-anhedonic potential in major depressive disorder, which speculatively, may be mediated by alterations in metabolic activity in the hippocampus, dACC and OFC. [ABSTRACT FROM AUTHOR]

A 56-year-old man complained progressive dyspnea, fatigue and fever for one month. His chest CT exhibited faint ground-glass opacities, and the levels of serum LDH and soluble interleukin 2 receptor were markedly elevated. Positron emission tomography (PET) showed high uptake of 18-fluoro deoxy glucose (18FDG) only on both lungs. We performed transbronchial lung biopsies (TBLB) for the diagnosis. After bronchoscopy, he had prolonged hypoxemia. Because defects of 99m-Technetium macroaggregated albumin (99mTc-MAA) in pulmonary blood flow scintigraphy were consistent with the distribution of 18FDG uptake in PET, we speculated that the presence of intravascular lymphoma (IVL) cells in the capillaries might have behaved like tumor embolism. We started rescue by prednisolone based on treatment of lymphoma. As a result, his hypoxemia was gradually improved. Histological findings in TBLB specimen showed that CD20+CD79+Bcl-2+c-myc+ lymphoma cells were localized to small vessel lumina in alveoli and bronchioles, and he was definitely diagnosed with lung intravascular large B cell lymphoma (IVLBCL). He was treated with complete cyclophosphamide, doxorubicin, vincristine, and prednisolone with rituximab (R–CHOP) in combination with intrathecal methotrexate injection. After eight cycles of R–CHOP and three times of intrathecal methotrexate, 18FDG uptake of PET on both lungs completely disappeared, achieving complete metabolic remission. We experienced a rare case of lung IVLBCL developed with respiratory failure successfully rescued by prednisolone prior to definite diagnosis. [ABSTRACT FROM AUTHOR]

Abstract: We describe a 15-year-old girl with subacute sclerosing panencephalitis (SSPE) in stage II who was treated with isoprinosine, intraventricular interferon alpha (IFN-α), and ribavirin for 3 years. She is alive at three years from onset and studies at school with the assistance of a special educational teacher. To assess residual brain function, serial 18FDG-positron emission tomography (PET) was performed three times to measure cortical metabolism: at onset, a year later, and three years later. At onset, PET study revealed preserved glucose metabolism of the cerebral cortex. In serial PET study, glucose metabolism of the cerebral cortex was also preserved even after three years. Although SSPE is a progressive disease of the neuronal system, and typically leads to death in approximately 2–3 years, the neurological prognosis of our case was good. We consider that combination therapy in the very early stage without hypometabolism in the cerebral cortex may be effective for SSPE. [Copyright &y& Elsevier]

Summary: Background: The objective of this study was to report 11 cases of malignant head and neck paraganglioma and to compare their epidemiological, clinical, and genetic characteristics, their natural history and their treatment with those of a series of 131 benign paragangliomas. Patients and methods: Retrospective analysis of 142 patients with head and neck paraganglioma managed between 2001 and 2008. Age at the time of diagnosis, gender, primary tumour site, presence of other non-head/neck paragangliomas and/or metastases diagnosed by imaging (CT, MRI, Octreoscan or 18F-FDG PET), histology, urinary catecholamine and metanephrine levels, family history, and genetic test results were recorded. Results: This series comprised 131 benign head and neck paragangliomas, mostly observed in women with a mean age at diagnosis of 45 years and a predominance of tympanojugular sites (followed by carotid and vagal sites) with 5% of secreting tumours and 20% of multifocal tumours. Eleven patients (7.7%) with a 1:1 sex ratio presented criteria of malignancy. These patients, with a lower mean age (38 years), predominantly presented carotid lesions with a higher rate of secreting and multifocal tumours, 27% and 46% respectively. The main sites of metastases were bone and lymph nodes. No tympanic paragangliomas were observed. Conclusions: Malignant paragangliomas are mainly observed in young patients with multifocal tumours, particularly carotid tumours, and are predominantly related to subunit SDH-B mutation. The work-up in these high-risk patients must include whole body scintigraphy and spine MRI. Malignancy is not necessarily associated with a poor short-term prognosis due to the slow course of the disease. [Copyright &y& Elsevier]

A 75-year-old woman was admitted to our department because of backache and multiple joint pain. Serum C-reactive protein (CRP) level was 6.8 mg/dL, and serum rheumatoid factor and anti-citrullinated peptide antibody were negative. Magnetic resonance imaging (MRI) showed bone edema and synovitis of the sacroiliac joints. 18Fluorodeoxyglucose-positron emission tomography (18FDG-PET) showed increased uptakes in the bilateral elbow, shoulder, sternoclavicular, hip, and sacroiliac joints. In addition, increased uptakes were also observed in the bilateral cervical and subclavian arteries, and the thoracic aorta. Moreover, inflammation of the vascular walls and an aneurism in the right subclavian artery were observed on MRI. The patient's HLA type was HLA-B48 and B60. According to the Assessment of Spondyloarthritis (ASAS) classification criteria, peripheral spondyloarthropathy (SpA) was also diagnosed. Although the diagnostic criteria of Takayasu aortitis or giant cell aortitis were not fulfilled, we thought that active aortitis was also involved, and high-dose prednisolone was started. The patient's symptoms were diminished immediately, and CRP levels returned to normal. Although the etiology of the aortitis was not certain, this is the first report of late-onset peripheral SpA with aortitis, diagnosed by 18FDG-PET and MRI. We recommended that it is important to evaluate the aortic involvement in late-onset SpA patients, when elevated systemic inflammation is observed. [ABSTRACT FROM AUTHOR]

Background: [18F]fluorodeoxyglucose (FDG)-PET is being evaluated as a tool for the early detection of response to various targeted agents in solid tumors. The aim of this study was to evaluate the predictive value of PET response after 2 days of erlotinib in unselected pretrated patients with stage IV NSCLC. Patients and methods: FDG-PET/CT scans were conducted at baseline and after 2 days of erlotinib, with a CT evaluation performed at baseline and after 45-60 days of therapy. PET responses were evaluated by quantitative changes on SUVmax tumor/non-tumor ratio and classified according to EORTC criteria. PET responses were compared with RECIST responses and related to progression-free (PFS) and overall (OS) survival. Erlotinib effects on glucose uptake were also studied in a panel of NSCLC cell lines. Results: Fifty-three patients were enrolled. At 2 days of erlotinib, 20 (38 %) patients showed partial metabolic response (PMR), 25 (47 %) had stable metabolic disease (SMD) and 8 (15 %) had progressive metabolic disease (PMD). All patients with PMD had confirmed RECIST progression at 45-60 days. Patients with early PMR and SMD had significantly longer PFS ( p < 0.001 and p = 0.001, respectively) and OS ( p = 0.001 for both) than PMD patients. Conclusions: FDG-PET assessment after 2 days of erlotinib could be useful to identify early resistent patients and to predict survival in unselected NSCLC pretreated population. [ABSTRACT FROM AUTHOR]

Résumé: Introduction: La maladie de Whipple est une maladie infectieuse rare due à Tropheryma whipplei, bactérie parfois responsable d’atteintes neurologiques graves isolées (25 cas rapportés dans la littérature), diagnostiquées le plus souvent par la positivité d’une PCR spécifique sur le LCR. Observation: Nous rapportons le troisième cas d’un syndrome associant obésité, démence et ataxie cérébelleuse. Le bilan étiologique était sans particularité ; seule une PCR T. whipplei dans la salive s’avérait fortement positive, la sérologie étant en faveur d’un portage de la bactérie. Le PET-scanner cérébral au 18FDG retrouvait un hypométabolisme frontal. Une antibiothérapie d’épreuve par doxycycline permettait une régression partielle des manifestations neurologiques et une perte de poids modérée et différée, l’hypométabolisme au PET-scanner régressant sous traitement. Conclusion: Le syndrome associant obésité, démence et ataxie cérébelleuse est une nouvelle entité clinique d’infection à T. whipplei. Un traitement d’épreuve par doxycycline peut aider au diagnostic et le PET-scanner pourrait être un des éléments du suivi. [ABSTRACT FROM AUTHOR]

Abstract: Objective: The aim of this study was to evaluate and validate magnetic resonance imaging (MRI) for the visualization and quantification of brown adipose tissue (BAT) in vivo in a rat model. We hypothesized that, based on differences in tissue water and lipid content, MRI could reliably differentiate between BAT and white adipose tissue (WAT) and could therefore be a possible alternative for 18 F-Fluorodeoxyglucose Positron Emission Tomography (18FDG-PET), the current gold standard for non-invasive BAT quantification. Materials/Methods: Eleven rats were studied using both 18FDG-PET/CT and MRI (1.5T). A dual echo (in-and-out-of-phase) sequence was used, both with and without spectral presaturation inversion recovery (SPIR) fat suppression (DUAL-SPIR) to visualize BAT, after which all BAT was surgically excised. The BAT volume measurements obtained via 18FDG-PET/CT and DUAL-SPIR MR were quantitatively compared with the histological findings. All study protocols were reviewed and approved by the local ethics committee. Results: The BAT mass measurements that were obtained using DUAL-SPIR MR subtraction images correlated better with the histological findings (P=0.017, R=0.89) than did the measurements obtained using 18FDG-PET/CT (P=0.78, R=0.15), regardless of the BAT metabolic activation state. Additionally, the basic feasibility of the DUAL-SPIR method was demonstrated in three human pilot subjects. Conclusions: This study demonstrates the potential for MRI to reliably detect and quantify BAT in vivo. MRI can provide information beyond that provided by 18FDG-PET imaging, and its ability to detect BAT is independent of its metabolic activation state. Additionally, MRI is a low-cost alternative that does not require radiation. [Copyright &y& Elsevier]

Abstract: Introduction: Stage III NSCLC patients are candidates for treatment with curative intent. Current guidelines advise post contrast magnetic resonance imaging (MRI) or contrast enhanced computed tomography (CE-CT) of the brain in these patients to exclude brain metastases (BM). In previous small studies MRI was reported to be superior to CE-CT. However, CT and MR technology have evolved and 18F-deoxyglucose-positron-emission-tomography (18FDG-PET) has been implemented in staging of NSCLC. If CE-CT, performed together with 18FDG-PET-CT shows the same yield of BM detection as an additionally performed MRI, substantial gain in time and resources is expected. Methods: All NSCLC patients who underwent a staging 18FDG-PET-CT between January 2008 and September 2011 were reviewed. Neurological asymptomatic patients with stage III NSCLC who were eligible for treatment with curative intent were selected, without taking into account the results of brain MRI. CT was compared to MRI to investigate whether additional BM were detected on MRI. Development of BM within a year after negative MRI was recorded. Results: 97/429 NSCLC patients who underwent a PET-CT had stage III disease. Three otherwise stage III patients already had occult BM on CE-CT. 77/97 (79%) patients underwent MRI, 45/77 (58%) CE-CT and 32/77 (42%) LD-CT. In none of the CE-CT, but in 5/32 (16%) LD-CT patients BM were detected on MRI. 9/72 patients (13%) without BM on MRI at diagnosis developed BM within a year. Conclusions: This retrospective study suggests that there is no additive value of MRI to 18FDG-PET-CT with CE-CT in screening for BM in neurological asymptomatic patients with stage III NSCLC. [Copyright &y& Elsevier]

Purpose This study aimed to evaluate if the F18-fluorodeoxyglucose positron emission tomography (F18-FDG PET) response after two weeks of chemoradiation for locoregionally advanced esophageal cancer (staged Tumor (T) 3 and/or Nodes (N)+ Metastases (M) 0) was linked to the pathologic response for patients undergoing surgery, to disease-free survival (DFS) or overall survival (OS). Materials and Methods Between March 2006 and September 2017, 40 patients were prospectively enrolled in our study, gave written consent, and had PET scans performed before treatment and after two weeks of chemoradiation. One patient did not undergo his two-week PET without informing study coordinators and was excluded from analyses. Results The median age at diagnosis was 62 years. Seventy-two percent of patients had N+ disease. Median OS for the entire group was 24 months. Five-year overall survival was 17%. Survival curves for patients with no PET response, minor PET response, or good PET response overlapped and were not statistically different. For the 25 patients who underwent surgery, the positive predictive value (PPV) of the PET response relative to the pathologic response was 75% and the negative predictive value (NPV) was 62%. In study patients, the crude recurrence rate was 68% and there was no correlation between PET response and DFS. Conclusion In our study, interim PET response after two weeks of chemoradiation for locoregionally advanced esophageal cancer was not predictive of outcome or pathologic response. Based on our data and current literature, interim PET should not be used to alter treatment (whether to escalate neo-adjuvant treatment or omit surgery)., Competing Interests: The authors have declared financial relationships, which are detailed in the next section., (Copyright © 2022, Lavertu et al.)

OBJECTIVES This study was conducted to evaluate the diagnostic role of matrix metalloproteinase 9 (MMP9) measured in bronchoalveolar lavage (BAL), serum and tissue samples of patients with indeterminate lung lesions and its correlation with F-18-2-fluoro-2-deoxyglucose-positron emission tomography (18FDG-PET) findings in diagnostic work. METHODS MMP9 levels (ng/ml) in serum and BAL were analysed using enzyme-linked immunosorbent assay in 60 consecutive patients with lung mass. 18FDG-PET was performed on all patients and a standard uptake value (SUV) threshold of 2.5 was used to differentiate benign from malignant lesions. In tissue samples of resectable patients, MMP9 expression was also revealed by immunohistochemical staining. RESULTS Twenty patients had benign disease and 40 patients had malignant lesions, of which 7 (17.5%) were classified as Stage I, 18 (45%) as Stage II, 7 (17.5%) as Stage III and 8 (20%) as Stage IV. MMP9 levels in serum were significantly higher in malignant than in benign lesions (673 ± 182 versus 309 ± 96, respectively, P < 0.0001), and were significantly higher in patients with metastatic disease than in patients of other stage groups; no significant difference was found between different histological types. MMP9 levels in BAL were higher in malignant than in benign lesions (502 ± 137 versus 325 ± 118, respectively, P = 0.001); no significant differences were found between different stages or histological groups. In patients with malignant lesions, MMP9 levels in BAL were inversely correlated with FEV1 (volume that has been exhaled at the end of the first second of forced expiration) and FVC (forced vital capacity of maximally forced expiratory effort) values. In patients with SUV > 2.5, MMP9 levels in serum and BAL had a sensitivity, specificity, positive predictive value and negative predictive value of 73, 100, 100 and 81% (cut-off point of 601; area under the curve (AUC): 0.7) and 94, 100, 100 and 83% (cut-off point of 745; AUC: 0.9), respectively. In patients with SUV < 2.5, MMP9 levels in serum and BAL had a sensitivity, specificity, positive predictive value and negative predictive value of 94, 100, 100 and 75% (cut-off point of 240; AUC: 0.9) and 70, 100, 100 and 73% (cut-off point of 321; AUC: 0.7), respectively. Of the 26 tumour samples, 9 (34%) showed positive immunohistochemical staining for MMP9. CONCLUSIONS The measurement of MMP9 levels helps to differentiate benign from malignant lung mass. Its use in combination with PET study adds further information to the diagnosis work-up of lesions to select patients who may or may not benefit from additional invasive procedures. [ABSTRACT FROM AUTHOR]

Abstract: In patients with non-small cell lung carcinoma (NSCLC) fluorine-18 fluorodeoxyglucose positron emission tomography (18FDG-PET)-scanning is shown to be of prognostic value. Small cell lung cancer (SCLC) is an aggressive tumor with poor prognosis. Limited results on the prognostic and predictive value of the maximum standard uptake values (SUVmax) obtained during 18FDG-PET scanning in SCLC are available. An observational study in 75 chemonaive patients diagnosed with SCLC who underwent a 18FDG-PET scan was performed. SUVmax values of the primary tumor were related to the overall survival (OS) and the progression free survival (PFS). Significant lower SUVmax values of the primary tumor were observed in patients with stage I–III disease compared to stage IV disease. SUVmax did not discriminate for either OS or PFS in the whole group of patients. In patients with stage IV disease and treatment with chemotherapy, OS and PFS were significantly higher in patients with a high SUVmax. (p-value 0.005 and 0.002 respectively) compared to patients with a low SUVmax value. In patients with SCLC metabolic activity determined using 18FDG-PET (SUVmax) differed between stage I–III and stage IV diseases. Compared to NSCLC, the relationship between SUVmax and prognosis seems more complex. [Copyright &y& Elsevier]

Accurate identification of viable myocardium is crucial in patient qualification for medical or surgical treatment. Only persons with confirmed cardiac viability will benefit from revascularization procedures. It is also well known, that the amount of viable myocardium assessed preoperatively is the best indicator of long term cardiac event free survival after cardiac intervention. There are several diagnostic approaches used in current clinical practice for assessment of myocardial viability. Analysis of wall thickness or myocardial contraction, evaluation of cardiac perfusion or metabolism can be assessed using following modalities: Echocardiography, Cardiac Molecular Imaging techniques (PET, SPECT), Cardiovascular MR or Cardiovascular CT. The article describes the methods and problems of viability assessment in 18FDG PET study. PET imaging has proved its accuracy and reproducibility for myocardial ischemia and viability assessment. However this unique in its ability for showing the particular substrate metabolism technique has unfortunately some disadvantages: currently achieved PET resolution is 0.4 cm. However the combined devices multislice computed tomography scanners with PET (PET/CT) are now widely used in clinical practice. This combination allows for wider morphologic assessments: coronary calcium scoring and non-invasive coronary angiography may be added to myocardial perfusion/metabolic imaging if necessary. [ABSTRACT FROM AUTHOR]

Purpose: Morphologic imaging techniques perform poorly in assessing the response to preoperative radiotherapy (RT), mainly because of desmoplastic reactions. The aim of this study was to investigate the potential of sequential 18-fluoro-2-deoxy-d-glucose (18FDG-PET) in assessing the response of rectal cancer to neoadjuvant RT and to determine which parameters can be used as surrogate markers for histopathologic response. Methods and Materials: 18FDG-PET scans were acquired before and during the 5th week after the end of RT. Tracer uptake was assessed semiquantitatively using standardized uptake values (SUV). The percentage differences (%Δ) between pre- and post-RT scans in SUVmax, SUVmean, metabolic volume (MV), and total glycolytic volume (tGV) were calculated. Results: Forty-five consecutive patients with histologically confirmed rectal adenocarcinoma were enrolled. After neoadjuvant RT, 20 of the 45 patients were classified as histopathologic responders and 25 as non-responders. Intense 18F-FDG uptake was seen in all tumors before neoadjuvant RT (average SUVmax 12.9 ± 6.0). When patients were classified as histologic responders and nonresponders, significant differences in %ΔSUVmax (55.8% vs. 37.4%, p = 0.023) and %ΔSUVmean (40.1% vs. 21.0%, p = 0.001) were observed between the two groups. For %ΔMV and %ΔtGV, decreases were more prominent in responders but were not significantly different from those in nonresponders. As demonstrated by receiver operating characteristic analysis, %ΔSUVmean was a more powerful discriminator than was %ΔSUVmax. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for optimal threshold of %ΔSUVmean (24.5%) were 80%, 72%, 76%, 70%, and 82% respectively. Conclusion: Sequential 18FDG-PET allows assessment of the response to preoperative RT. Both %ΔSUVmean and %ΔSUVmax correlate with histopathologic response and can be used to evaluate and compare the effectiveness of different neoadjuvant treatment strategies. The maximum accuracy figures and the positive predictive value figures for both Δ%SUVmean and Δ%SUVmax are, however, too low to justify modification of the standard treatment protocol of an individual patient. [Copyright &y& Elsevier]

Epileptic neurological disorders in infants are often difficult to distinguish, and call for disparate treatments. Positron emission tomography (PET) using an [F] fluoro-2-deoxyglucose (FDG) tracer, is a powerful non-invasive technique successful in improving the diagnosis of a number of conditions. Interestingly, this technique has shown that cerebral glucose hypometabolism is present in children with epileptic encephalopathies (EE). Ten children with age-dependent EE were recruited and routine FDG PET images were evaluated for their ability to indicate cerebral glucose metabolism both before and after anti-epileptic treatment. We found that there is diffuse glucose hypometabolism in both hemispheres before treatment, indicating EE. Following treatment, the number of epileptic episodes significantly decreased ( P < 0.05), while cerebral glucose metabolism improved. Our findings suggest that FDG PET can be utilized to monitor cerebral glucose metabolism as a measure of treatment progress in EE. [ABSTRACT FROM AUTHOR]

Background: High-frequency bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) is a promising treatment in refractory obsessive-compulsive disorder (OCD). Method: Using the crossover, randomized, and double-blind procedure adopted by the STOC study, 10 patients treated with high-frequency bilateral STN DBS underwent am 18-fluorodeoxyglucose positron emission tomography (PET) investigation to highlight the neural substratum of this therapeutic approach. Results: The median Yale–Brown Obsessive Compulsive Scale (Y-BOCS) scores for all 10 patients were 31 (minimum = 18, maximum = 36) with “Off-Stimulation” status and 19 (minimum = 0, maximum = 30) with “On-Stimulation” status (p = .05). The OCD patients in Off-Stimulation status showed a hypermetabolism in the right frontal middle and superior gyri, right parietal lobe, postcentral gyrus, and bilateral putamen compared with healthy control subjects. A significant decrease in cerebral metabolism was observed in the left cingulate gyrus and the left frontal medial gyrus in On-Stimulation conditions compared with Off-Stimulation conditions. In addition, the improvement assessed by Y-BOCS scores during the On-Stimulation conditions was positively correlated with PET signal changes at the boundary of the orbitofrontal cortex and the medial prefrontal cortex, between PET signal changes and the Y-BOCS scores modifications in On-Stimulation status. Conclusion: This study suggests that the therapeutic effect of STN DBS is related to a decrease in prefrontal cortex metabolism. [ABSTRACT FROM AUTHOR]

Summary: Hemimegalencephaly (HME) presents as severe refractory seizures and requires early surgical treatment to prevent progression to catastrophic epilepsy. Single-photon emission computed tomography (SPECT) and positron emission tomography (PET) are useful imaging techniques for the presurgical evaluation of patients with intractable epilepsy. However, the results in HME are variable and no study has compared SPECT and PET performed at around the same time. We performed SPECT and PET for nine patients with HME, which was defined as a whole or part of affected hemisphere enlargement (three males, six females; age range 0.5–20 years). The ictal and interictal states were determined based on the presence or absence of clinical seizures during all PET examinations and majority of SPECT examinations. The perfusion pattern in the malformed hemisphere was increased or equal, despite the reduced glucose metabolism in six out of nine patients. Five of the six patients who underwent early surgical treatment showed this kind of perfusion/metabolism discrepancy. Importantly, even the non-affected hemisphere in early infantile cases already lacked the normal hypoperfusion and hypometabolism patterns of immature frontal lobes, which was most prominent in case with poor surgical prognosis. In all six surgical patients, epileptic seizures appeared before 4 months of age. By contrast, none of the non-surgical patients had seizures before 4 months of age. In conclusion, although the number of patients examined is small and the result is still preliminary, the perfusion/metabolism discrepancy found in this study may show potential characteristic aspect of HME and further study with simultaneous EEG recording will make clear if this finding can be useful indicator for early surgical treatment in HME. [ABSTRACT FROM AUTHOR]

Background:18FDG-PET plays a significant role in diagnosing malignancy of lung lesions but remains an expensive test available at a limited number of sites in Italy. Objective: We prospectively compare the diagnostic accuracy of 99mTc-MIBI- SPECT and 18FDG-PET in patients with indeterminate lung lesions to demonstrate that 99mTc-MIBI-SPECT may be considered as a valid alternative when 18FDG-PET is not available. Methods: 52 patients with indeterminate lung lesion were examined by 18FDG-PET and 99mTc-MIBI-SPECT before surgery. The scintigraphic findings were analyzed visually and semiquantitatively and then correlated to the definitive diagnosis. Results: 38 were malignant lesions while 14 were benign. At visual analysis, the sensitivities of 18FDG-PET and 99mTc-MIBI-SPECT were 92 and 84%, respectively (McNemar test p = 0.4), whereas the specificities were 78.6 and of 93% (p = 1.0), respectively. At semiquantitative analysis, 18FDG-PET showed a sensitivity and specificity of 92 and 71.4%, respectively, while 99mTc-MIBI-SPECT produced a sensitivity and specificity of 86 and 100%, respectively (p = 0.194). For lymph node staging, 18FDG-PET and 99mTc-MIBI-SPECT have a sensitivity and specificity of 88 and 92 of 77 and 100%, respectively. Conclusion:99mTc-MIBI-SPECT is similar to 18FDG-PET in the detection of lung malignancies and represents an alternative when PET is not available. Yet, the combination of both techniques may improve patient selection for surgery. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]