34 research outputs found
STUDI PERILAKU SEKSUAL PADA KELOMPOK GAY :PENGETAHUAN, SIKAP DAN NILAI DI GUBUG SEBAYA KABUPATEN JOMBANG
<p><b>Objectives:</b> Recent research suggested an influence of diminished central nervous serotonin (5-HT) synthesis on the leptin axis via immunological mechanisms in healthy adult females. However, studies assessing immunological parameters in combination with dietary challenge techniques that impact brain 5-HT synthesis in humans are lacking. </p> <p><b>Methods:</b> In the present trial, a pilot analysis was conducted on data obtained in healthy adult humans receiving either different dietary acute tryptophan depletion (ATD) challenge or tryptophan (TRP)-balanced control conditions (BAL) to study the effects of reduced central nervous 5-HT synthesis on serum tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and IL-6 concentrations. The data of <i>N</i> = 35 healthy adults were analysed who were randomly subjected to one of the following two dietary conditions in a double-blind between-subject approach: (1) The Moja-De ATD challenge (ATD), or (2) TRP-balanced control condition for ATD Moja-De (BAL). Serum concentrations for the assessment of relevant parameters (TNF-α, IL-1β and IL-6) and relevant TRP-related characteristics after the respective challenge procedures were assessed at baseline (T0) and in hourly intervals after administration over a period of 6 h (T1–T6). </p> <p><b>Results:</b> The ATD condition did not result in significant changes to cytokine concentrations for the entire study sample, or in male and female subgroups. Depletion of CNS 5-HT via dietary TRP depletion appears to have no statistically significant short-term impact on cytokine concentrations in healthy adults. </p> <p><b>Conclusions:</b> Future research on immunological stressors in combination with challenge techniques will be of value in order to further disentangle the complex interplay between brain 5-HT synthesis and immunological pathways.</p
Erratum to: Amino acid PET and MR perfusion imaging in brain tumours (vol 5, pg 209, 2017)
FET PET RADIOMICS - DIAGNOSIS OF PSEUDOPROGRESSION IN GLIOBLASTOMA PATIENTS BASED ON TEXTURAL FEATURES
AbstractIntroduction: The differentiation of pseudoprogression (PsP) from tumor progression (TP) in glioblastoma patients is difficult on the basis of standard MRI alone. Textural feature analysis as part of the concept of radiomics offers a quantitative method to describe tumor heterogeneity and gains increasing interest in the field of neuro-oncology. In our study, we investigated the potential of textural features of O-(2-[18F]fluoroethyl)-L-tyrosine (FET) PET to discriminate between PsP and TP in glioblastoma patients. Materials and Methods: Twenty-three newly diagnosed glioblastoma patients with MRI findings suspicious for TP within 12 weeks after completion of chemoradiation with temozolomide underwent an additional dynamic FET PET scan. Volumes-of-interest were defined on summed images from 20-40 min post-injection (p.i.) by a 3-dimensional auto-contouring process using a tumor-to-brain ratio (TBR) of 1.6 or more. For each lesion, TBRs and the time-activity curves (TACs) of the FET uptake were determined. The TACs were used to evaluate the dynamic FET PET parameters time-to-peak (TTP), slope (slope of linear regression line 20-50 min p.i.) and intercept (intercept of linear regression line with y-axis). Additionally, 39 textural parameters were calculated using the software LifeX (lifexsoft.org). The diagnostic accuracy of TBRs, TTP, slope, intercept, and textural parameters to discriminate between PsP and TP was evaluated using ROC analyses. In order to further increase the diagnostic accuracy, parameters were combined using linear logistic regression for classification of PsP and TP. Results: Fourteen patients had a clinico-radiological diagnosis of TP and nine patients had PsP. The FET PET parameters TBRmean, TBRmax, TTP and intercept yielded a diagnostic accuracy to discriminate between PsP and TP of 79%, 79%, 58%, 63%, respectively. The dynamic FET PET parameter slope yielded the highest diagnostic accuracy of 83% to discriminate between PsP and TP. Two textural features showed a comparable accuracy of 79%. The diagnostic accuracy could not be increased by combination of parameters. Conclusions: Textural features yielded a comparable diagnostic accuracy for diagnosis of pseudoprogression in glioblastoma patients in comparison with static and dynamic FET PET parameters. Textural features might yield additional valuable information for this highly relevant clinical problem and should be further evaluated in larger cohort prospective studies
FET PET radiomics - diagnosis of pseudoprogression in glioblastoma patients based on textural features
AbstractIntroduction: The differentiation of pseudoprogression (PsP) from tumor progression (TP) in glioblastoma patients is difficult on the basis of standard MRI alone. Textural feature analysis as part of the concept of radiomics offers a quantitative method to describe tumor heterogeneity and gains increasing interest in the field of neuro-oncology. In our study, we investigated the potential of textural features of O-(2-[18F]fluoroethyl)-L-tyrosine (FET) PET to discriminate between PsP and TP in glioblastoma patients. Materials and Methods: Twenty-three newly diagnosed glioblastoma patients with MRI findings suspicious for TP within 12 weeks after completion of chemoradiation with temozolomide underwent an additional dynamic FET PET scan. Volumes-of-interest were defined on summed images from 20-40 min post-injection (p.i.) by a 3-dimensional auto-contouring process using a tumor-to-brain ratio (TBR) of 1.6 or more. For each lesion, TBRs and the time-activity curves (TACs) of the FET uptake were determined. The TACs were used to evaluate the dynamic FET PET parameters time-to-peak (TTP), slope (slope of linear regression line 20-50 min p.i.) and intercept (intercept of linear regression line with y-axis). Additionally, 39 textural parameters were calculated using the software LifeX (lifexsoft.org). The diagnostic accuracy of TBRs, TTP, slope, intercept, and textural parameters to discriminate between PsP and TP was evaluated using ROC analyses. In order to further increase the diagnostic accuracy, parameters were combined using linear logistic regression for classification of PsP and TP. Results: Fourteen patients had a clinico-radiological diagnosis of TP and nine patients had PsP. The FET PET parameters TBRmean, TBRmax, TTP and intercept yielded a diagnostic accuracy to discriminate between PsP and TP of 79%, 79%, 58%, 63%, respectively. The dynamic FET PET parameter slope yielded the highest diagnostic accuracy of 83% to discriminate between PsP and TP. Two textural features showed a comparable accuracy of 79%. The diagnostic accuracy could not be increased by combination of parameters. Conclusions: Textural features yielded a comparable diagnostic accuracy for diagnosis of pseudoprogression in glioblastoma patients in comparison with static and dynamic FET PET parameters. Textural features might yield additional valuable information for this highly relevant clinical problem and should be further evaluated in larger cohort prospective studies
FET PET Radiomics - Differenzierung von Tumorprogression und Pseudoprogression beim Glioblastom basierend auf Texturmerkmalen
PREDICTING ISOCITRATE DEHYDROGENASE GENOTYPE IN MALIGNANT GLIOMA USING FET PET RADIOMICS
Comment on hatzoglou et al: Dynamic contrastenhanced MRI perfusion versus 18FDG PET/CT in differentiating brain tumor progression from radiation injury
Volumetric assessment of recurrent or progressive gliomas: comparison between F-DOPA PET and perfusion-weighted MRI
Purpose: To compare the diagnostic information obtained with 6-[18F]-fluoro-l-3,4-dihydroxyphenylalanine (F-DOPA) PET and relative cerebral blood volume (rCBV) maps in recurrent or progressive glioma. Methods: All patients with recurrent or progressive glioma referred for F-DOPA imaging at our institution between May 2010 and May 2014 were retrospectively included, provided that macroscopic disease was visible on conventional MRI images and that rCBV maps were available for comparison. The final analysis included 50 paired studies (44 patients). After image registration, automatic tumour segmentation of both sets of images was performed using the average signal in a large reference VOI including grey and white matter multiplied by 1.6. Tumour volumes identified by both modalities were compared and their spatial congruence calculated. The distances between F-DOPA uptake and rCBV hot spots, tumour-to-brain ratios (TBRs) and normalized histograms were also computed. Results: On visual inspection, 49 of the 50 F-DOPA and 45 of the 50 rCBV studies were classified as positive. The tumour volume delineated using F-DOPA (F-DOPAvol 1.6) greatly exceeded that of rCBV maps (rCBVvol 1.6). The median F-DOPAvol 1.6 and rCBVvol 1.6 were 11.44 ml (range 0 – 220.95 ml) and 1.04 ml (range 0 – 26.30 ml), respectively (p < 0.00001). Overall, the median overlapping volume was 0.27 ml, resulting in a spatial congruence of 1.38 % (range 0 – 39.22 %). The mean hot spot distance was 27.17 mm (±16.92 mm). F-DOPA uptake TBR was significantly higher than rCBV TBR (1.76 ± 0.60 vs. 1.15 ± 0.52, respectively; p < 0.0001). The histogram analysis showed that F-DOPA provided better separation of tumour from background. In 6 of the 50 studies (12 %), however, physiological uptake in the striatum interfered with tumour delineation. Conclusion: The information provided by F-DOPA PET and rCBV maps are substantially different. Image interpretation is easier and a larger tumour extent is identified on F-DOPA PET images than on rCBV maps. The clinical impact of such differences needs to be explored in future studies
Case Report: Disruption of Resting-State Networks and Cognitive Deficits After Whole Brain Irradiation for Singular Brain Metastasis
Introduction: Long-term survivors of whole brain radiation (WBRT) are at significant risk for developing cognitive deficits, but knowledge about the underlying pathophysiological mechanisms is limited. Therefore, we here report a rare case with a singular brain metastasis treated by resection and WBRT that survived for more than 10 years where we investigated the integrity of brain networks using resting-state functional MRI.Methods: A female patient with a left frontal non-small cell lung cancer (NSCLC) brain metastasis had resection and postoperative WBRT (30.0 in 3.0 Gy fractions) and stayed free from brain metastasis recurrence for a follow-up period of 11 years. Structural magnetic resonance imaging (MRI) and amino acid [O-(2-[F-18]fluoroethyl)-L-tyrosine] positron emission tomography (FET PET) were repeatedly acquired. At the last follow up, neurocognitive functions and resting-state functional connectivity (RSFC) using resting-state fMRI were assessed. Within-network and inter-network connectivity of seven resting-state networks were computed from a connectivity matrix. All measures were compared to a matched group of 10 female healthy subjects.Results: At the 11-year follow-up, T2/FLAIR MR images of the patient showed extended regions of hyper-intensities covering mainly the white mater of the bilateral dorsal frontal and parietal lobes while sparing most of the temporal lobes. Compared to the healthy subjects, the patient performed significantly worse in all cognitive domains that included executive functions, attention and processing speed, while verbal working memory, verbal episodic memory, and visual working memory were left mostly unaffected. The connectivity matrix showed a heavily disturbed pattern with a widely distributed, scattered loss of RSFC. The within-network RSFC revealed a significant loss of connectivity within all seven networks where the dorsal attention and fronto-parietal control networks were affected most severely. The inter-network RSFC was significantly reduced for the visual, somato-motor, and dorsal and ventral attention networks.Conclusion: As demonstrated here in a patient with a metastatic NSCLC and long-term survival, WBRT may lead to extended white matter damage and cause severe disruption of the RSFC in multiple resting state networks. In consequence, executive functioning which is assumed to depend on the interaction of several networks may be severely impaired following WBRT apart from the well-recognized deficits in memory function.</p