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Diabetologia Notes de lecture     Hybrid Journal  
Diabetology Intl.     Hybrid Journal   (Followers: 1)
Dialectical Anthropology     Hybrid Journal   (Followers: 7, SJR: 0.109, h-index: 7)
Die Weltwirtschaft     Hybrid Journal   (Followers: 2)
Differential Equations     Hybrid Journal   (Followers: 2, SJR: 0.28, h-index: 14)
Differential Equations and Dynamical Systems     Hybrid Journal   (Followers: 1, SJR: 0.337, h-index: 5)
Digestive Diseases and Sciences     Hybrid Journal   (Followers: 4, SJR: 0.803, h-index: 84)
Directieve therapie     Hybrid Journal  
Discrete & Computational Geometry     Hybrid Journal   (Followers: 2, SJR: 1.088, h-index: 37)
Discrete Event Dynamic Systems     Hybrid Journal   (Followers: 2, SJR: 1.028, h-index: 30)
Distributed and Parallel Databases     Hybrid Journal   (Followers: 4, SJR: 0.82, h-index: 29)
Distributed Computing     Hybrid Journal   (Followers: 2, SJR: 1.361, h-index: 29)
DNP - Der Neurologe und Psychiater     Full-text available via subscription  
Documenta Ophthalmologica     Hybrid Journal   (Followers: 2, SJR: 1.418, h-index: 37)
Doklady Biochemistry and Biophysics     Hybrid Journal   (Followers: 2, SJR: 0.18, h-index: 8)
Doklady Biological Sciences     Hybrid Journal   (SJR: 0.193, h-index: 9)
Doklady Botanical Sciences     Hybrid Journal  
Doklady Chemistry     Hybrid Journal   (SJR: 0.261, h-index: 11)
Doklady Earth Sciences     Hybrid Journal   (SJR: 0.386, h-index: 15)
Doklady Mathematics     Hybrid Journal   (SJR: 0.299, h-index: 12)
Doklady Physical Chemistry     Hybrid Journal   (SJR: 0.316, h-index: 10)
Doklady Physics     Hybrid Journal   (Followers: 1, SJR: 0.274, h-index: 14)
Douleur et Analg├ęsie     Hybrid Journal   (SJR: 0.135, h-index: 5)
Drug Delivery and Translational Research     Hybrid Journal   (Followers: 2, SJR: 0.624, h-index: 6)
Drug Safety - Case Reports     Open Access  
Drugs : Real World Outcomes     Hybrid Journal  
Dynamic Games and Applications     Hybrid Journal   (Followers: 2)
Dysphagia     Hybrid Journal   (Followers: 229, SJR: 0.684, h-index: 46)
e & i Elektrotechnik und Informationstechnik     Hybrid Journal   (Followers: 9, SJR: 0.146, h-index: 8)
e-Neuroforum     Hybrid Journal  
Early Childhood Education J.     Hybrid Journal   (Followers: 13, SJR: 0.367, h-index: 12)
Earth Science Informatics     Hybrid Journal   (Followers: 3, SJR: 0.245, h-index: 5)
Earth, Moon, and Planets     Hybrid Journal   (Followers: 6, SJR: 0.436, h-index: 28)
Earthquake Engineering and Engineering Vibration     Hybrid Journal   (Followers: 7, SJR: 0.433, h-index: 17)
Earthquake Science     Hybrid Journal   (Followers: 8, SJR: 0.486, h-index: 7)
East Asia     Hybrid Journal   (Followers: 7, SJR: 0.165, h-index: 9)
Eating and Weight Disorders - Studies on Anorexia, Bulimia and Obesity     Hybrid Journal   (Followers: 8, SJR: 0.289, h-index: 23)
EcoHealth     Hybrid Journal   (Followers: 1, SJR: 0.651, h-index: 22)
Ecological Research     Hybrid Journal   (Followers: 8, SJR: 0.698, h-index: 38)
Economia e Politica Industriale     Hybrid Journal  
Economia Politica     Hybrid Journal  
Economic Botany     Hybrid Journal   (Followers: 9, SJR: 0.666, h-index: 40)
Economic Bulletin     Hybrid Journal   (Followers: 4)
Economic Change and Restructuring     Hybrid Journal   (Followers: 1, SJR: 0.263, h-index: 6)
Economic Theory     Hybrid Journal   (Followers: 9, SJR: 1.857, h-index: 31)
Economic Theory Bulletin     Hybrid Journal   (Followers: 2)
Economics of Governance     Hybrid Journal   (Followers: 2, SJR: 0.367, h-index: 12)
Ecosystems     Hybrid Journal   (Followers: 19, SJR: 1.793, h-index: 83)
Ecotoxicology     Hybrid Journal   (Followers: 10, SJR: 1.041, h-index: 53)
Education and Information Technologies     Hybrid Journal   (Followers: 228, SJR: 0.207, h-index: 15)
Educational Assessment, Evaluation and Accountability     Hybrid Journal   (Followers: 17, SJR: 0.519, h-index: 14)
Educational Psychology Review     Hybrid Journal   (Followers: 15, SJR: 1.781, h-index: 52)
Educational Research for Policy and Practice     Hybrid Journal   (Followers: 7, SJR: 0.211, h-index: 8)
Educational Studies in Mathematics     Hybrid Journal   (Followers: 11, SJR: 0.946, h-index: 27)
Educational Technology Research and Development     Partially Free   (Followers: 214, SJR: 1.124, h-index: 45)
Electrical Engineering     Hybrid Journal   (Followers: 13, SJR: 0.352, h-index: 17)
Electrocatalysis     Hybrid Journal   (SJR: 0.542, h-index: 7)
Electronic Commerce Research     Hybrid Journal   (Followers: 4, SJR: 0.636, h-index: 14)
Electronic Markets     Hybrid Journal   (Followers: 5, SJR: 0.326, h-index: 5)
Electronic Materials Letters     Hybrid Journal   (Followers: 3, SJR: 0.566, h-index: 11)
Elemente der Mathematik     Hybrid Journal   (Followers: 1)
Emergency Radiology     Hybrid Journal   (Followers: 4, SJR: 0.446, h-index: 22)
Emission Control Science and Technology     Hybrid Journal  
Empirica     Hybrid Journal   (Followers: 3, SJR: 0.185, h-index: 12)
Empirical Economics     Hybrid Journal   (Followers: 8, SJR: 0.5, h-index: 29)
Empirical Software Engineering     Hybrid Journal   (Followers: 5, SJR: 2.319, h-index: 33)
Employee Responsibilities and Rights J.     Hybrid Journal   (Followers: 2, SJR: 0.21, h-index: 13)
Endocrine     Hybrid Journal   (Followers: 5, SJR: 0.659, h-index: 55)
Endocrine Pathology     Hybrid Journal   (Followers: 2, SJR: 0.555, h-index: 27)
Energy Efficiency     Hybrid Journal   (Followers: 11, SJR: 1.056, h-index: 10)
Energy Systems     Hybrid Journal   (Followers: 10, SJR: 0.589, h-index: 5)
Engineering With Computers     Hybrid Journal   (Followers: 5, SJR: 0.497, h-index: 26)
Entomological Review     Hybrid Journal   (Followers: 3, SJR: 0.128, h-index: 5)
Environment Systems & Decisions     Hybrid Journal   (Followers: 2)
Environment, Development and Sustainability     Hybrid Journal   (Followers: 28, SJR: 0.319, h-index: 26)
Environmental and Ecological Statistics     Hybrid Journal   (Followers: 5, SJR: 0.389, h-index: 29)
Environmental and Resource Economics     Hybrid Journal   (Followers: 18, SJR: 1.651, h-index: 46)
Environmental Biology of Fishes     Hybrid Journal   (Followers: 4, SJR: 0.486, h-index: 53)
Environmental Chemistry Letters     Hybrid Journal   (Followers: 2, SJR: 0.664, h-index: 22)
Environmental Earth Sciences     Hybrid Journal   (Followers: 11, SJR: 0.601, h-index: 55)
Environmental Economics and Policy Studies     Hybrid Journal   (Followers: 6, SJR: 0.35, h-index: 3)
Environmental Evidence     Open Access  
Environmental Fluid Mechanics     Hybrid Journal   (Followers: 2, SJR: 0.732, h-index: 23)
Environmental Geochemistry and Health     Hybrid Journal   (Followers: 2, SJR: 0.909, h-index: 32)
Environmental Geology     Hybrid Journal   (Followers: 11)
Environmental Health and Preventive Medicine     Hybrid Journal   (Followers: 2, SJR: 0.388, h-index: 14)
Environmental Management     Hybrid Journal   (Followers: 32, SJR: 0.773, h-index: 60)
Environmental Modeling & Assessment     Hybrid Journal   (Followers: 11, SJR: 0.413, h-index: 27)
Environmental Monitoring and Assessment     Hybrid Journal   (Followers: 8, SJR: 0.671, h-index: 46)
Environmental Science and Pollution Research     Hybrid Journal   (Followers: 14, SJR: 0.878, h-index: 42)
Epidemiologic Perspectives & Innovations     Open Access   (Followers: 2, SJR: 1.002, h-index: 14)
Epileptic Disorders     Hybrid Journal   (Followers: 1, SJR: 0.669, h-index: 34)
EPJ A - Hadrons and Nuclei     Hybrid Journal   (Followers: 1, SJR: 1.435, h-index: 58)
EPJ B - Condensed Matter and Complex Systems     Hybrid Journal   (Followers: 3, SJR: 0.749, h-index: 85)
EPJ direct     Hybrid Journal  
EPJ E - Soft Matter and Biological Physics     Hybrid Journal   (Followers: 1, SJR: 0.661, h-index: 57)
EPMA J.     Open Access   (SJR: 0.161, h-index: 4)
ERA-Forum     Hybrid Journal   (Followers: 2, SJR: 0.13, h-index: 2)
Erkenntnis     Hybrid Journal   (Followers: 12, SJR: 0.62, h-index: 14)
Erwerbs-Obstbau     Hybrid Journal   (SJR: 0.173, h-index: 8)

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Journal Cover   European Journal of Nuclear Medicine and Molecular Imaging
  [SJR: 1.724]   [H-I: 80]   [10 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1619-7089 - ISSN (Online) 1619-7070
   Published by Springer-Verlag Homepage  [2300 journals]
  • Test–retest reliability of the novel 5-HT 1B receptor PET
           radioligand [ 11 C]P943
    • Abstract: Purpose [11C]P943 is a novel, highly selective 5-HT1B PET radioligand. The aim of this study was to determine the test–retest reliability of [11C]P943 using two different modeling methods and to perform a power analysis with each quantification technique. Methods Seven healthy volunteers underwent two PET scans on the same day. Regions of interest (ROIs) were the amygdala, hippocampus, pallidum, putamen, insula, frontal, anterior cingulate, parietal, temporal and occipital cortices, and cerebellum. Two multilinear radioligand quantification techniques were used to estimate binding potential: MA1, using arterial input function data, and the second version of the multilinear reference tissue model analysis (MRTM2), using the cerebellum as the reference region. Between-scan percent variability and intraclass correlation coefficients (ICC) were used to assess test–retest reliability. We also performed power analyses to determine the method that would allow the least number of subjects using within-subject or between-subject study designs. A voxel-wise ICC analysis for MRTM2 BPND was performed for the whole brain and all the ROIs studied. Results Mean percent variability between two scans across regions ranged between 0.4 % and 12.4 % for MA1 BPND, 0.5 % and 11.5 % for MA1 BPP, 16.7 % and 28.3 % for MA1 BPF, and between 0.2 % and 5.4 % for MRTM2 BPND. The power analyses showed a greater number of subjects were required using MA1 BPF compared with other outcome measures for both within-subject and between-subject study designs. ICC values were the highest using MRTM2 BPND and the lowest with MA1 BPF in ten ROIs. Small regions and regions with low binding had lower ICC values than large regions and regions with high binding. Conclusion Reliable measures of 5-HT1B receptor binding can be obtained using the novel PET radioligand [11C]P943. Quantification of 5-HT1B receptor binding with MRTM2 BPND and with MA1 BPP provided the least variability and optimal power for within-subject and between-subject designs.
      PubDate: 2015-03-01
  • Cortical hypermetabolism in MCI subjects: a compensatory mechanism'
    • Abstract: Purpose Alzheimer’s disease (AD) is associated with amyloid accumulation that takes place decades before symptoms appear. Cognitive impairment in AD is associated with reduced glucose metabolism. However, neuronal plasticity/compensatory mechanisms might come into play before the onset of dementia. The aim of this study was to determine whether there is evidence of cortical hypermetabolism as a compensatory mechanism before amyloid deposition takes place in subjects with amnestic mild cognitive impairment (aMCI). Methods Nine AD subjects and ten aMCI subjects had both [11C]PIB and [18F]FDG PET scans with arterial input in order to quantify the amyloid deposition and glucose metabolism in vivo in comparison with healthy control subjects who underwent either [11C]PIB or [18F]FDG PET scans. The [11C]PIB PET scans were quantified using [11C]PIB target region to cerebellum uptake ratio images created by integrating the activity collected from 60 to 90 min, and regional cerebral glucose metabolism was quantified using spectral analysis. Results In MCI subjects, cortical hypermetabolism was observed in four amyloid-negative subjects and one amyloid-positive subject, while hypometabolism was seen in five other MCI subjects with high amyloid load. Subjects with hypermetabolism and low amyloid did not convert to AD during clinical follow-up for 18 months in contrast to four amyloid-positive hypometabolic subjects who did convert to AD. Conclusion This preliminary study suggests that compensatory hypermetabolism can occur in aMCI subjects, particularly in those who are amyloid-negative. The increase in metabolic rate in different cortical regions with predominance in the occipital cortex may be a compensatory response to the neuronal damage occurring early in the disease process. It may also reflect recruitment of relatively minimally affected cortical regions to compensate for reduced function in the temporoparietal cortical association areas.
      PubDate: 2015-03-01
  • 68 Ga-NOTA-exendin-4 PET/CT in detection of occult insulinoma and
           evaluation of physiological uptake
    • PubDate: 2015-03-01
  • Zone-size nonuniformity of 18 F-FDG PET regional textural features
           predicts survival in patients with oropharyngeal cancer
    • Abstract: Purpose The question as to whether the regional textural features extracted from PET images predict prognosis in oropharyngeal squamous cell carcinoma (OPSCC) remains open. In this study, we investigated the prognostic impact of regional heterogeneity in patients with T3/T4 OPSCC. Methods We retrospectively reviewed the records of 88 patients with T3 or T4 OPSCC who had completed primary therapy. Progression-free survival (PFS) and disease-specific survival (DSS) were the main outcome measures. In an exploratory analysis, a standardized uptake value of 2.5 (SUV 2.5) was taken as the cut-off value for the detection of tumour boundaries. A fixed threshold at 42 % of the maximum SUV (SUVmax 42 %) and an adaptive threshold method were then used for validation. Regional textural features were extracted from pretreatment 18F-FDG PET/CT images using the grey-level run length encoding method and grey-level size zone matrix. The prognostic significance of PET textural features was examined using receiver operating characteristic (ROC) curves and Cox regression analysis. Results Zone-size nonuniformity (ZSNU) was identified as an independent predictor of PFS and DSS. Its prognostic impact was confirmed using both the SUVmax 42 % and the adaptive threshold segmentation methods. Based on (1) total lesion glycolysis, (2) uniformity (a local scale texture parameter), and (3) ZSNU, we devised a prognostic stratification system that allowed the identification of four distinct risk groups. The model combining the three prognostic parameters showed a higher predictive value than each variable alone. Conclusion ZSNU is an independent predictor of outcome in patients with advanced T-stage OPSCC, and may improve their prognostic stratification.
      PubDate: 2015-03-01
  • [ 18 F]DPA-714 PET imaging of translocator protein TSPO (18 kDa) in
           the normal and excitotoxically-lesioned nonhuman primate brain
    • Abstract: Purpose We aimed to characterize pharmacologically the TSPO- radioligand [18F]DPA-714 in the brain of healthy cynomolgus monkeys and evaluate the cellular origin of its binding in a model of neurodegeneration induced by intrastriatal injection of quinolinic acid (QA). Methods [18F]DPA-714 PET images were acquired before and at 2, 7, 14, 21, 49, 70, 91 days after putaminal lesioning. Blocking and displacement studies were carried out (PK11195). Different modelling approaches estimated rate constants and V T (total distribution volume) which was used to measure longitudinal changes in the lesioned putamen. Sections for immunohistochemical labelling were prepared at the same time-points to evaluate correlations between in vivo [18F]DPA-714 binding and microglial/astrocytic activation. Results [18F]DPA-714 showed a widespread distribution with a higher signal in the thalamus and occipital cortex and lower binding in the cerebellum. TSPO was expressed throughout the whole brain and about 73 % of [18F]DPA-714 binding was specific for TSPO in vivo. The one-tissue compartment model (1-TCM) provided good and reproducible estimates of V T and rate constants, and V T values from the 1-TCM and the Logan approach were highly correlated (r 2 = 0.85). QA lesioning induced an increase in V T, which was +17 %, +54 %, +157 % and +39 % higher than baseline on days 7, 14, 21 and 91 after QA injection, respectively. Immunohistochemistry revealed an early microglial and a delayed astrocytic activation after QA injection. [18F]DPA-714 binding matched TSPO immunopositive areas and showed a stronger colocalization with CD68 microglia than with GFAP-activated astrocytes. Conclusion [18F]DPA-714 binds to TSPO with high specificity in the primate brain under normal conditions and in the QA model. This tracer provides a sensitive tool for assessing neuroinflammation in the human brain.
      PubDate: 2015-03-01
  • Positron emission tomography imaging of the 18-kDa translocator protein
           (TSPO) with [ 18 F]FEMPA in Alzheimer’s disease patients and control
    • Abstract: Purpose Imaging of the 18-kDa translocator protein (TSPO) is a potential tool for examining microglial activation and neuroinflammation in early Alzheimer’s disease (AD). [18F]FEMPA is a novel high-affinity second-generation TSPO radioligand that has displayed suitable pharmacokinetic properties in preclinical studies. The aims of this study were to quantify the binding of [18F]FEMPA to TSPO in AD patients and controls and to investigate whether higher [18F]FEMPA binding in AD patients than in controls could be detected in vivo. Methods Ten AD patients (five men, five women; age 66.9 ± 7.3 years; MMSE score 25.5 ± 2.5) and seven controls (three men, four women; age 63.7 ± 7.2 years, MMSE score 29.3 ± 1.0) were studied using [18F]FEMPA at Turku (13 subjects) and at Karolinska Institutet (4 subjects). The in vitro binding affinity for TSPO was assessed using PBR28 in a competition assay with [3H]PK11195 in seven controls and eight AD patients. Cortical and subcortical regions of interest were examined. Quantification was performed using a two-tissue compartment model (2TCM) and Logan graphical analysis (GA). The outcome measure was the total distribution volume (V T). Repeated measures analysis of variance was used to assess the effect of group and TSPO binding status on V T. Results Five AD patients and four controls were high-affinity binders (HABs). Three AD patients and three controls were mixed-affinity binders. V T estimated with Logan GA was significantly correlated with V T estimated with the 2TCM in both controls (r = 0.97) and AD patients (r = 0.98) and was selected for the final analysis. Significantly higher V T was found in the medial temporal cortex in AD patients than in controls (p = 0.044) if the TSPO binding status was entered as a covariate. If only HABs were included, significantly higher V T was found in the medial and lateral temporal cortex, posterior cingulate, caudate, putamen, thalamus and cerebellum in AD patients than in controls (p < 0.05). Conclusion [18F]FEMPA seems to be a suitable radioligand for detecting increased TSPO binding in AD patients if their binding status is taken into account.
      PubDate: 2015-03-01
  • Predictive value of early 18 F-FDG PET/CT studies for treatment response
           evaluation to ipilimumab in metastatic melanoma: preliminary results of an
           ongoing study
    • Abstract: Purpose Ipilimumab is a newly approved immunotherapeutic agent that has been shown to provide a survival benefit in patients with metastatic melanoma. 18F-FDG PET/CT has demonstrated very satisfying results in detecting melanoma metastases in general. Using 18F-FDG PET/CT we monitored patients with metastatic melanoma undergoing ipilimumab therapy during the course of treatment. The aim of our study was to evaluate the role of 18F-FDG PET/CT performed after two cycles of ipilimumab in predicting the final response to therapy. Methods In 22 patients suffering from unresectable metastatic melanoma, scheduled for ipilimumab treatment PET/CT scanning was performed before the start of treatment (baseline scan), after two cycles of treatment (early response) and at the end of treatment after four cycles (late response). Evaluation of the patient response to treatment on PET was based on the European Organization for Research and Treatment of Cancer 1999 criteria. Progression-free survival (PFS) and overall survival (OS) data are presented. Results After the end of treatment, 15 patients were characterized as having progressive metabolic disease (PMD) and five as having stable metabolic disease (SMD), and two patients showed a partial metabolic response (PMR). Early PET/CT performed after two ipilimumab cycles predicted treatment response in 13 of the 15 PMD patients, in five of the five SMD patients and in neither of the two PMR patients. Both patients with PMR showed pseudoprogression after the second cycle and were therefore wrongly classified. According to the patients’ clinical outcome, patients with late PMD had a median PFS of 3.6 months (mean 5.6 months), while patients with late SMD had a median PFS of 9.8 months (mean 9.0 months). In comparison, patients with early PMD had a median PFS of 2.7 months (mean 5.5 months) and patients with early SMD had a median PFS of 6.3 months (mean 7.5 months). The difference in PFS between the two groups was statistically significant for both early and late responses (log-rank p < 0.001). Median OS among patients with late PMD was 9.1 months (mean 11.2 months) and among those with late SMD 9.8 months (mean 10.7 months). The difference in OS between the two groups was statistically significant (log-rank p = 0.013). The median OS among patients with early PMD was 8.8 months (mean 12.0 months) and among those with early SMD 9.8 months (mean 10.0 months). The difference in OS between the two groups was statistically significant (log-rank p < 0.001). Conclusion 18F-FDG PET/CT after two cycles of ipilimumab is highly predictive of the final treatment outcome in patients with PMD and SMD.
      PubDate: 2015-03-01
  • Current status and future role of brain PET/MRI in clinical and research
    • Abstract: Abstract Hybrid PET/MRI systematically offers a complementary combination of two modalities that has often proven itself superior to the single modality approach in the diagnostic work-up of many neurological and psychiatric diseases. Emerging PET tracers, technical advances in multiparametric MRI and obvious workflow advantages may lead to a significant improvement in the diagnosis of dementia disorders, neurooncological diseases, epilepsy and neurovascular diseases using PET/MRI. Moreover, simultaneous PET/MRI is well suited to complex studies of brain function in which fast fluctuations of brain signals (e.g. related to task processing or in response to pharmacological interventions) need to be monitored on multiple levels. Initial simultaneous studies have already demonstrated that these complementary measures of brain function can provide new insights into the functional and structural organization of the brain.
      PubDate: 2015-03-01
  • Nonsurgical giant cell tumour of the tendon sheath or of the diffuse type:
           Are MRI or 18 F-FDG PET/CT able to provide an accurate prediction of
           long-term outcome'
    • Abstract: Purpose To investigate whether MRI (RECIST 1.1, WHO criteria and the volumetric approach) or 18F-FDG PET/CT (PERCIST 1.0) are able to predict long-term outcome in nonsurgical patients with giant cell tumour of the tendon sheath or of the diffuse type (GCT-TS/DT). Methods Fifteen “nonsurgical” patients with a histological diagnosis of GCT-TS/DT were divided into two groups: symptomatic patients receiving targeted therapy and asymptomatic untreated patients. All 15 patients were evaluated by MRI of whom 10 were treated, and a subgroup of 7 patients were evaluated by PET/CT of whom 4 were treated. Early evolution was assessed according to MRI and PET/CT scans at baseline and during follow-up. Cohen’s kappa coefficient was used to evaluate the degree of agreement between PERCIST 1.0, RECIST 1.1, WHO criteria, volumetric approaches and the reference standard (long-term outcome, delay 505 ± 457 days). The response rate in symptomatic patients with GCT-TS/DT receiving targeted therapy was also assessed in a larger population that included additional patients obtained from a review of the literature. Results The kappa coefficients for agreement between RECIST/WHO/volumetric criteria and outcome (15 patients) were respectively: 0.35 (p = 0.06), 0.26 (p = 0.17) and 0.26 (p = 0.17). In the PET/CT subgroup (7 patients), PERCIST was in perfect agreement with the late symptomatic evolution (kappa = 1, p < 0.05). In the treated symptomatic group including the additional patients from the literature the response rates to targeted therapies according to late symptomatic assessment, and PERCIST and RECIST criteria were: 65 % (22/34), 77 % (10/13) and 26 % (10/39). Conclusion 18F-FDG PET/CT with PERCIST is a promising approach to the prediction of the long-term outcome in GCT-TS/DT and may avoid unnecessary treatments, toxicity and costs. On MRI, WHO and volumetric approaches are not more effective than RECIST using the current thresholds.
      PubDate: 2015-03-01
  • 18 F-GE-180: a novel TSPO radiotracer compared to 11 C-R-PK11195 in a
           preclinical model of stroke
    • Abstract: Purpose Neuroinflammation plays a critical role in various neuropathological conditions, and hence there is renewed interest in the translocator protein (TSPO) as a biomarker of microglial activation and macrophage infiltration in the brain. This is reflected in the large amount of research conducted seeking to replace the prototypical PET radiotracer 11C-R-PK11195 with a TSPO ligand with higher performance. Here we report the in vivo preclinical investigation of the novel TSPO tracer 18F-GE-180 in a rat model of stroke. Methods Focal cerebral ischaemia was induced in Wistar rats by 60-min occlusion of the middle cerebral artery (MCAO). Brain damage was assessed 24 h after MCAO by T2 MRI. Rats were scanned with 11C-R-PK11195 and 18F-GE-180 5 or 6 days after MCAO. Specificity of binding was confirmed by injection of unlabelled R-PK11195 or GE-180 20 min after injection of 18F-GE-180. In vivo data were confirmed by ex vivo immunohistochemistry for microglial (CD11b) and astrocytic biomarkers (GFAP). Results 18F-GE-180 uptake was 24 % higher in the core of the ischaemic lesion and 18 % lower in the contralateral healthy tissue than that of 11C-R-PK11195 uptake (1.5 ± 0.2-fold higher signal to noise ratio). We confirmed this finding using the simplified reference tissue model (BPND = 3.5 ± 0.4 and 2.4 ± 0.5 for 18F-GE-180 and 11C-R-PK11195, respectively, with R 1 = 1). Injection of unlabelled R-PK11195 or GE-180 20 min after injection of 18F-GE-180 significantly displaced 18F-GE-180 (69 ± 5 % and 63 ± 4 %, respectively). Specificity of the binding was also confirmed by in vitro autoradiography, and the location and presence of activated microglia and infiltrated macrophages were confirmed by immunohistochemistry. Conclusion The in vivo binding characteristics of 18F-GE-180 demonstrate a better signal to noise ratio than 11C-R-PK11195 due to both a better signal in the lesion and lower nonspecific binding in healthy tissue. These results provide evidence that 18F-GE-180 is a strong candidate to replace 11C-R-PK11195.
      PubDate: 2015-03-01
  • S. Ted Treves: Pediatric nuclear medicine and molecular imaging
    • PubDate: 2015-03-01
  • Early post-treatment FDG PET predicts survival after 90 Y microsphere
           radioembolization in liver-dominant metastatic colorectal cancer
    • Abstract: Purpose The aim of this study was to evaluate the predictive value of early metabolic response 4 weeks post-treatment using 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT in patients with unresectable hepatic metastases of colorectal cancer (CRC) undergoing radioembolization (RE) with 90Y-labelled microspheres. Methods A total of 51 consecutive patients with liver-dominant metastases of CRC were treated with RE and underwent 18F-FDG PET/CT at baseline and 4 weeks after RE. In each patient, three hepatic metastases with the highest maximum standardized uptake value (SUVmax) were selected as target lesions. Metabolic response was defined as >50 % reduction of tumour to liver ratios. Survival analyses using Kaplan-Meier and multivariate analyses were performed to identify prognostic factors for overall survival (OS). Investigated baseline characteristics included age (>60 years), performance status (Eastern Cooperative Oncology Group >1), bilirubin (>1.0 mg/dl), hepatic tumour burden (>25 %) and presence of extrahepatic disease. Results The median OS after RE was 7 months [95 % confidence interval (CI) 5–8]; early metabolic responders (n = 33) survived longer than non-responders (p < 0.001) with a median OS of 10 months (95 % CI 3–16) versus 4 months (95 % CI 2–6). Hepatic tumour burden also had significant impact on treatment outcome (p < 0.001) with a median OS of 5 months (95 % CI, 3–7) for patients with >25 % metastatic liver replacement vs 14 months (95 % CI 6–22) for the less advanced patients. Both factors (early metabolic response and low hepatic tumour burden) remained as independent predictors of improved survival on multivariate analysis. Conclusion These are the first findings to show that molecular response assessment in CRC using 18F-FDG PET/CT appears feasible as early as 4 weeks post-RE, allowing risk stratification and potentially facilitating early response-adapted treatment strategies.
      PubDate: 2015-03-01
  • 18 F-FDG PET-derived parameters as prognostic indices in hepatic
           malignancies after 90 Y radioembolization: is there a role'
    • PubDate: 2015-03-01
  • Increased evidence for the prognostic value of primary tumor asphericity
           in pretherapeutic FDG PET for risk stratification in patients with head
           and neck cancer
    • Abstract: Purpose In a previous study, we demonstrated the first evidence that the asphericity (ASP) of pretherapeutic FDG uptake in the primary tumor provides independent prognostic information in patients with head and neck cancer. The aim of this work was to confirm these results in an independent patient group examined at a different site. Methods FDG-PET/CT was performed in 37 patients. The primary tumor was delineated by an automatic algorithm based on adaptive thresholding. For the resulting ROIs, the metabolically active part of the tumor (MTV), SUVmax, SUVmean, total lesion glycolysis (TLG) and ASP were computed. Univariate Cox regression with respect to progression free survival (PFS) and overall survival (OS) was performed. For survival analysis, patients were divided in groups of high and low risk according to the parameter cut-offs defined in our previous work. In a second step, the cut-offs were adjusted to the present data. Univariate and multivariate Cox regression was performed for the pooled data consisting of the current and the previously described patient group (N = 68). In multivariate Cox regression, clinically relevant parameters were included. Results Univariate Cox regression using the previously published cut-off values revealed TLG (hazard ratio (HR) = 3) and ASP (HR = 3) as significant predictors for PFS. For OS MTV (HR = 2.7) and ASP (HR = 5.9) were significant predictors. Using the adjusted cutoffs MTV (HR = 2.9/3.3), TLG (HR = 3.1/3.3) and ASP (HR = 3.1/5.9) were prognostic for PFS/OS. In the pooled data, multivariate Cox regression revealed a significant prognostic value with respect to PFS/OS for MTV (HR = 2.3/2.1), SUVmax (HR = 2.1/2.5), TLG (HR = 3.5/3.6), and ASP (HR = 3.4/4.4). Conclusions Our results confirm the independent prognostic value of ASP of the pretherapeutic FDG uptake in the primary tumor in patients with head and neck cancer. Moreover, these results demonstrate that ASP can be determined unambiguously across different sites.
      PubDate: 2015-03-01
  • Prognostic impact of 18 F-FDG PET/CT staging and of pathological response
           to neoadjuvant chemotherapy in triple-negative breast cancer
    • Abstract: Purpose Mortality is high in patients with locally advanced triple-negative breast cancer (TNBC), especially in those with residual tumour after neoadjuvant chemotherapy (NAC). The aim of this study was to determine if pretreatment 18F-FDG PET/CT staging and pathological findings after NAC could together allow stratification of patients into prognostic groups. Methods Initial staging with 18F-FDG PET/CT was performed prospectively in 85 consecutive patients with stage II/III TNBC. Correlations between PET findings and disease-specific survival (DSS) were examined. In patients without distant metastases on PET staging, the impact of pathological response to NAC on DSS was examined. Patterns of recurrence were also analysed. Results 18F-DG PET/CT revealed distant metastases in 11 of 85 patients (12.9 %). Among 74 M0 patients, 23 (31.1 %) showed a pathological complete response (pCR) at surgery, while 51 had residual invasive disease (no pCR). DSS differed considerably among the three groups of patients (log-rank P < .001): among patients with occult metastases on baseline PET/CT, 2-year DSS was 18.2 %, and among patients without initial metastases on PET/CT, 5-year DSS was 61.3 % in patients without pCR after NAC and 95.2 % in those with pCR. Of the 51 patients who did not achieve pCR, 21 relapsed (17 developed distant metastases). The sites of distant recurrence were: lung/pleura (nine patients), brain (eight patients), liver (six patients), distant lymph nodes (six patients) and bone (five patients). Conclusion In patients with clinical stage II/III TNBC, 18F-FDG PET/CT findings at initial staging and pathological response at the end of NAC allow three groups of patients with quite different prognoses to be defined. Extraskeletal recurrences predominated. Specific follow-up strategies in patients with TNBC who do not achieve pCR deserve investigation.
      PubDate: 2015-03-01
  • Uptake and tracer kinetics of O -(2- 18 F-fluoroethyl)- l -tyrosine in
           meningiomas: preliminary results
    • Abstract: Purpose O-(2-[18F]Fluoroethyl)-l-tyrosine (18F-FET) is a well-established PET tracer for the imaging of cerebral gliomas, but little is known about 18F-FET uptake in meningiomas. The aim of this study was to explore 18F-FET kinetics and tumour-to-background contrast in meningiomas of various histologies. Methods A group of 24 patients with suspected cerebral meningioma on MRI/CT had an additional dynamic 18F-FET PET scan prior to surgery. Time–activity curves (TAC) of 18F-FET uptake in the tumours and tumour-to-brain ratios (TBR) for early (3 – 14 min after injection) and late 18F-FET uptake (20 – 40 min after injection) were analysed and compared with histological subtypes and WHO grade. 18F-FET uptake in critical structures in the skull base was also evaluated in terms of tumour-to-tissue (T/Tis) ratio. Results TBR of 18F-FET uptake in meningiomas was significantly higher in the early phase than in the late phase (3.5 ± 0.8 vs. 2.2 ± 0.3; P < 0.001). The difference in TBR between low-grade meningiomas (WHO grade I, 18 patients) and high-grade meningiomas (WHO grade II or III, 6 patients) was significant in the late phase of 18F-FET uptake (2.1 ± 0.2 vs. 2.5 ± 0.2, P = 0.003) while there was no significant difference in the early phase. ROC analysis showed that TBR of 18F-FET uptake in the late phase had significant power to differentiate low-grade from high-grade meningiomas (AUC 0.87 ± 0.18, sensitivity 83 %, specificity 83 %, optimal cut-off 2.3; P < 0.01). Evaluation of TAC yielded three different curve patterns of 18F-FET PET uptake. Combination of TBR (cut-off value 2.3) and TAC pattern slightly improved the differentiation of high-grade from low-grade meningiomas (accuracy 92 %; P = 0.001). Analysis of background radioactivity in the skull base indicated that 18F-FET uptake may be helpful in distinguishing meningioma tissue in the late phase. T/Tis ratios were >1.2 in all patients for the periorbita, sphenoidal sinus, pituitary gland, tentorium, bone and brain, in more than 90 % of patients for the mucosa and dura, but in only 63 % of patients for the cavernous sinus. Conclusion 18F-FET PET may provide additional information for noninvasive grading of meningiomas and possibly for the discrimination of tumour in critical areas of the skull base. A further evaluation of 18F-FET PET in meningiomas appears to be justified.
      PubDate: 2015-03-01
  • Extensive melorheostosis of the ribs demonstrated on 18 F-Fluoride PET/CT
    • PubDate: 2015-03-01
  • 18 F-FDOPA PET/CT imaging of insulinoma revisited
    • Abstract: Purpose 18F-FDOPA PET imaging is increasingly used in the work-up of patients with neuroendocrine tumours. It has been shown to be of limited value in localizing pancreatic insulin-secreting tumours in adults with hyperinsulinaemic hypoglycaemia (HH) mainly due to 18F-FDOPA uptake by the whole pancreatic gland. The objective of this study was to review our experience with 18F-FDOPA PET/CT imaging with carbidopa (CD) premedication in patients with HH in comparison with PET/CT studies performed without CD premedication in an independent population. Methods A retrospective study including 16 HH patients who were investigated between January 2011 and December 2013 using 18F-FDOPA PET/CT (17 examinations) in two academic endocrine tumour centres was conducted. All PET/CT examinations were performed under CD premedication (200 mg orally, 1 – 2 h prior to tracer injection). The PET/CT acquisition protocol included an early acquisition (5 min after 18F-FDOPA injection) centred over the upper abdomen and a delayed whole-body acquisition starting 20 – 30 min later. An independent series of eight consecutive patients with HH and investigated before 2011 were considered for comparison. All patients had a reference whole-body PET/CT scan performed about 1 h after 18F-FDOPA injection. In all cases, PET/CT was performed without CD premedication. Results In the study group, 18F-FDOPA PET/CT with CD premedication was positive in 8 out of 11 patients with histologically proven insulinoma (73 %). All 18F-FDOPA PET/CT-avid insulinomas were detected on early images and 5 of 11 (45 %) on delayed ones. The tumour/normal pancreas uptake ratio was not significantly different between early and delayed acquisitions. Considering all patients with HH, including those without imaging evidence of disease, the detection rate of the primary lesions using CD-assisted 18F-FDOPA PET/CT was 53 %, showing 9 insulinomas in 17 studies performed. In the control group (without CD premedication, eight patients), the final diagnosis was benign insulinoma in four, nesidioblastosis in one, and no definitive diagnosis in the remainder. 18F-FDOPA PET/CT failed to detect any tumour in these patients. Conclusion According to our experience, CD administration before 18F-FDOPA injection leads to low residual pancreatic 18F-FDOPA activity preserving tumoral uptake with consequent insulinoma detection in more than half of adult patients with HH and more than 70 % of patients with a final diagnosis of insulinoma. If 18F-FDOPA PET/CT is indicated, we strongly recommend combining CD premedication with early acquisition centred over the pancreas.
      PubDate: 2015-03-01
  • Preclinical evaluation of [ 18 F]2FNQ1P as the first fluorinated serotonin
           5-HT 6 radioligand for PET imaging
    • Abstract: Purpose Brain serotonin 6 receptor (5-HT6) is one of the most recently identified serotonin receptors. It is a potent therapeutic target for psychiatric and neurological diseases, e.g. schizophrenia and Alzheimer’s disease. Since no specific fluorinated radioligand has yet been successfully used to study this receptor by positron emission tomography (PET) neuroimaging, the objective of the present study was to study the first 5-HT6 18F-labelled radiotracer. Methods 2FNQ1P, inspired by the quinolone core of a previous radiotracer candidate, GSK215083, was selected according its 5-HT6 affinity and selectivity and was radiolabelled by 18F nucleophilic substitution. The cerebral distribution of [18F]2FNQ1P was studied in vivo in rats, cats and macaque monkeys. Results The chemical and radiochemical purities of [18F]2FNQ1P were >98 %. In rats, in vitro competition with the 5-HT6 antagonist, SB258585, revealed that the radioligand was displaced dose dependently. Rat microPET studies showed low brain uptake of [18F]2FNQ1P, reversed by the P-glycoprotein inhibitor, cyclosporin. On the contrary, PET scans in cats showed good brain penetration and specific striatal binding blocked after pretreatment with unlabelled 2FNQ1P. PET scans in macaque monkeys confirmed high specific binding in both cortical and subcortical regions, specifically decreased by pretreatment with the 5-HT6 receptor antagonist, SB258585. Conclusion 2FNQ1P was initially selected because of its suitable characteristics for 5-HT6 receptor probing in vitro in terms of affinity and specificity. Although in vivo imaging in rats cannot be considered as predictive of the clinical characteristics of the radiotracer, [18F]2FNQ1P appeared to be a suitable 5-HT6 PET tracer in feline and primate models. These preclinical results encourage us to pursue the clinical development of this first fluorinated 5-HT6 PET radiotracer.
      PubDate: 2015-03-01
  • Antonio Luna, Joan C. Vilanova, L. Celso Hygino da Cruz Jr, Santiago E.
           Rossi (eds): Functional imaging in oncology. Biophysical basis and
           technical approaches—Volume 1
    • PubDate: 2015-03-01
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