scholarly journals Evaluation of FET PET Radiomics Feature Repeatability in Glioma Patients

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 647
Author(s):  
Robin Gutsche ◽  
Jürgen Scheins ◽  
Martin Kocher ◽  
Khaled Bousabarah ◽  
Gereon R. Fink ◽  
...  
Keyword(s):  
Intraclass Correlation ◽  
Hierarchical Cluster ◽  
Diagnostic Value ◽  
Fet Pet ◽  
Tumor Patient ◽  
Amino Acid Pet ◽  
Feature Based ◽  
Occurrence Matrix ◽  
Spherical Tumor ◽  
High Repeatability

Amino acid PET using the tracer O-(2-[18F]fluoroethyl)-L-tyrosine (FET) has attracted considerable interest in neurooncology. Furthermore, initial studies suggested the additional diagnostic value of FET PET radiomics in brain tumor patient management. However, the conclusiveness of radiomics models strongly depends on feature generalizability. We here evaluated the repeatability of feature-based FET PET radiomics. A test–retest analysis based on equivalent but statistically independent subsamples of FET PET images was performed in 50 newly diagnosed and histomolecularly characterized glioma patients. A total of 1,302 radiomics features were calculated from semi-automatically segmented tumor volumes-of-interest (VOIs). Furthermore, to investigate the influence of the spatial resolution of PET on repeatability, spherical VOIs of different sizes were positioned in the tumor and healthy brain tissue. Feature repeatability was assessed by calculating the intraclass correlation coefficient (ICC). To further investigate the influence of the isocitrate dehydrogenase (IDH) genotype on feature repeatability, a hierarchical cluster analysis was performed. For tumor VOIs, 73% of first-order features and 71% of features extracted from the gray level co-occurrence matrix showed high repeatability (ICC 95% confidence interval, 0.91–1.00). In the largest spherical tumor VOIs, 67% of features showed high repeatability, significantly decreasing towards smaller VOIs. The IDH genotype did not affect feature repeatability. Based on 297 repeatable features, two clusters were identified separating patients with IDH-wildtype glioma from those with an IDH mutation. Our results suggest that robust features can be obtained from routinely acquired FET PET scans, which are valuable for further standardization of radiomics analyses in neurooncology.

scholarly journals 32. TREATMENT MONITORING OF IMMUNOTHERAPY AND TARGETED THERAPY USING AMINO ACID PET IN PATIENTS WITH BRAIN METASTASES

2020 ◽  
Vol 2 (Supplement_2) ◽  
pp. ii5-ii6
Author(s):  
Norbert Galldiks ◽  
Diana Abdulla ◽  
Matthias Scheffler ◽  
Fabian Wolpert ◽  
Jan-Michael Werner ◽  
...  
Keyword(s):  
Targeted Therapy ◽  
Amino Acid ◽  
Brain Metastases ◽  
Response Assessment ◽  
Diagnostic Value ◽  
Treatment Monitoring ◽  
Fet Pet ◽  
Time To Peak ◽  
Amino Acid Pet

Abstract PURPOSE Recently, the RANO group has analyzed the additional diagnostic value of amino acid PET in patients with primary and secondary brain tumors and recommended the use of this imaging technique in addition to conventional MRI. Here, we investigated the value of PET using the radiolabled amino acid O-(2-[18F]fluoroethyl)-L-tyrosine (FET) for treatment monitoring of immune checkpoint inhibition (ICI) or targeted therapy (TT) alone or in combination with radiotherapy in patients with brain metastases (BM) since contrast-enhanced MRI often remains inconclusive. METHODS We retrospectively identified 40 patients with 107 BM secondary to melanoma (n=29 with 75 BM) or non-small cell lung cancer (n=11 with 32 BM) treated with ICI or TT who had FET PET (n=60 scans) for treatment monitoring from 2015–2019. The majority of patients (n=37; 92.5%) had radiotherapy during the course of disease. In 27 patients, FET PET was used for the differentiation of treatment-related changes from BM relapse following ICI or TT. In 13 patients, FET PET was performed for response assessment to ICI or TT using baseline and follow-up scans (median time between scans, 4.2 months). In all lesions, static and dynamic FET PET parameters were obtained (i.e., mean tumour-to-brain ratios (TBR), time-to-peak values). Diagnostic accuracies of PET parameters were evaluated by receiver-operating-characteristic analyses using the clinical follow-up or neuropathological findings as reference. RESULTS A TBR threshold of 1.95 differentiated BM relapse from treatment-related changes with an accuracy of 85% (P=0.003). Metabolic Responders to ICI or TT on FET PET had a significantly longer stable follow-up (threshold of TBR reduction relative to baseline, ≥10%; accuracy, 82%; P=0.004). Furthermore, at follow-up, time-to-peak values in metabolic responders increased significantly (P=0.019). CONCLUSIONS FET PET may add valuable information for treatment monitoring in BM patients treated with ICI or TT.

scholarly journals Repeatability of automated measurements by a new anterior segment optical coherence tomographer and biometer and agreement with standard devices

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Domenico Schiano-Lomoriello ◽  
Kenneth J. Hoffer ◽  
Irene Abicca ◽  
Giacomo Savini
Keyword(s):  
Intraclass Correlation ◽  
Anterior Segment ◽  
Consecutive Series ◽  
Optical Coherence ◽  
Limits Of Agreement ◽  
Automated Measurements ◽  
Deviation Coefficient ◽  
Corneal Diameter ◽  
High Repeatability ◽  
Good Agreement

AbstractWe assess repeatability of automatic measurements of a new anterior segment optical coherence tomographer and biometer (ANTERION) and their agreement with those provided by an anterior segment-optical coherence tomography device combined with Placido-disk corneal topography (MS-39) and a validated optical biometer (IOLMaster 500). A consecutive series of patients underwent three measurements with ANTERION and one with MS-39. A subgroup of patients underwent biometry also with IOLMaster 500. Repeatability was assessed by means of within-subject standard deviation, coefficient of variation (COV), and intraclass correlation coefficient (ICC). Agreement was investigated with the 95% limits of agreement. Paired t-test and Wilcoxon matched-pairs test were performed to compare the measurements of the different devices. Repeatability of ANTERION measurements was high, with ICC > 0.98 for all parameters except astigmatism (0.963); all parameters apart from those related to astigmatism revealed a COV < 1%. Repeatability of astigmatism improved when only eyes whose keratometric astigmatism was higher than 1.0 D were investigated. Most measurements by ANTERION and MS-39 showed good agreement. No significant differences were found between measurements by ANTERION and IOLMaster, but for corneal diameter. ANTERION revealed high repeatability of automatic measurements and good agreement with both MS-39 and IOLMaster for most parameters.

scholarly journals A novel collagen area fraction index to quantitatively assess bowel fibrosis in patients with Crohn’s disease

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Xue-hua Li ◽  
Zhuang-nian Fang ◽  
Tian-ming Guan ◽  
Jin-jiang Lin ◽  
Can-hui Sun ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
Intraclass Correlation ◽  
Area Under The Curve ◽  
Area Fraction ◽  
Strongly Correlated ◽  
Fibrosis Score ◽  
High Repeatability

Abstract Background A validated histopathological tool to precisely evaluate bowel fibrosis in patients with Crohn’s disease is lacking. We attempted to establish a new index to quantify the severity of bowel fibrosis in patients with Crohn’s disease-associated fibrostenosis. Methods We analyzed the histopathological data of 31 patients with Crohn’s disease strictures undergoing surgical resection. The most representative sections of resected strictured segments were stained with Masson trichrome to manifest bowel fibrosis. The collagen area fraction and histological fibrosis score were simultaneously calculated for the same section to evaluate the severity of bowel fibrosis. Results Collagen area fraction strongly correlated with histological fibrosis scores (r = 0.733, P < 0.001). It showed a stronger correlation (r = 0.561, P < 0.001) with the degree of bowel strictures than the histological fibrosis score did (r = 0.468, P < 0.001). It was also shown to be more accurate for diagnosing Crohn’s disease strictures (area under the receiver operating characteristic curve = 0.815, P < 0.001) compared with the histological fibrosis score (area under the curve = 0.771, P < 0.001). High repeatability was observed for the collagen area fraction, with an intraclass correlation coefficient of 0.915 (P < 0.001). Conclusions Collagen area fraction is a simple and reliable index to quantify the severity of bowel fibrosis in patients with Crohn’s disease-associated fibrostenosis.

scholarly journals NIMG-38. NON-INVASIVE PREDICTION OF MGMT PROMOTER METHYLATION USING COMBINED FET PET/MRI RADIOMICS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii156-ii156
Author(s):  
Philipp Lohmann ◽  
Anna-Katharina Meissner ◽  
Jan-Michael Werner ◽  
Gabriele Stoffels ◽  
Martin Kocher ◽  
...  
Keyword(s):  
Promoter Methylation ◽  
Methylation Status ◽  
Mgmt Promoter Methylation ◽  
Test Dataset ◽  
Fet Pet ◽  
Promoter Methylation Status ◽  
Non Invasive ◽  
Mgmt Promoter ◽  
Amino Acid Pet ◽  
Mgmt Promoter Methylation Status

Abstract BACKGROUND Recently, the Response Assessment in Neuro-Oncology (RANO) Working Group emphasized the additional diagnostic value of amino acid PET in addition to MRI. However, the number of studies using amino acid PET/MRI radiomics is still low. We investigated the potential of combined O-(2-[18F]fluoroethyl)-L-tyrosine (FET) PET/MRI radiomics for the non-invasive prediction of the O6-methylguanine-DNA methyl-transferase (MGMT) promoter methylation status in glioma patients. METHODS Seventy-one patients with newly diagnosed glioma (predominantly WHO grade III and IV glioma, 82%) underwent a hybrid FET PET/MRI scan. Forty-six patients (65%) had a methylated MGMT promoter. The tumor and tumor subregions were manually segmented on conventional MRI. In total, 199 standardized features were obtained from FET PET, contrast-enhanced T1-weighted, T2-weighted, and fluid attenuated inversion recovery (FLAIR) MRI. After feature extraction and data normalization, patients were randomly assigned to a training and a test dataset for final model evaluation in a ratio of 70/30, with a balanced distribution of the MGMT promoter methylation status. Feature selection was performed by recursive feature elimination using random forest regressors. For the final model generation, the number of features was limited to seven to avoid data overfitting. Different algorithms for model generation were compared, and the model performance in the training data was assessed by 5-fold cross-validation. Finally, the best performing models were applied to the test dataset to evaluate the robustness of the models. RESULTS In the test dataset, the best radiomics signatures obtained from MRI or FET PET alone achieved diagnostic accuracies for the prediction of the MGMT promoter methylation of 64% and 70%, respectively. In contrast, the highest diagnostic accuracy of 83% was obtained by combining FET PET and MRI features. CONCLUSION Combined FET PET/MRI radiomics allows the non-invasive prediction of the MGMT promoter methylation status in patients with gliomas, providing more diagnostic information than either modality alone.

scholarly journals Status Quo of Professional–Patient Relations in the Internet Era: Bibliometric and Co-Word Analyses

2019 ◽  
Vol 16 (7) ◽  
pp. 1183 ◽  
Author(s):  
Zekun Wang ◽  
Zhaohua Deng ◽  
Xiang Wu
Keyword(s):  
New Media ◽  
Computer Network ◽  
Hierarchical Cluster ◽  
The Internet ◽  
The Past ◽  
Bradford’S Law ◽  
Patient Relations ◽  
Occurrence Matrix ◽  
Professional Patient Relations

Background: Incidents of violence against medical staff have increased in intensity, showing the deteriorating relationship between doctors and patients in China over the past few years. In addition, professional–patient relations have been significantly affected in the Internet era in China, which has attracted great attention from many scholars. This study aims to analyze the research status of professional–patient relations in the Internet era in China and further reveal its research pattern and trends. Methods: This study collected journal articles published during the past 21 years from the Wanfang Data Knowledge Service Platform. Then, bibliometric analysis was carried out, including publication growth, core author and collaborative degree, highly cited papers, journal distribution, and institution distribution analyses. We also analyzed the subject heading–source literature matrix and co-occurrence matrix of keywords through hierarchical cluster, social network, and strategic diagram analyses. Results: The number of articles has continually risen since 1998, which follows the growth law of literature. Furthermore, the distribution of these studies obeys Bradford’s law of scattering, and mainly concentrates on the fields of medicine and health technology. The distribution of high-frequency keywords follows Zipf’s law. Conclusions: We identified eight focal research directions, namely: website building (especially for professional–patient interaction), telemedicine, professional–patient communication and network public opinion, professional–patient contradiction and health education, new media, follow-up interaction platform, healthcare reform and computer network, and medical ethics.

scholarly journals Color image steganalysis based on embedding change probabilities in differential channels

2020 ◽  
Vol 16 (5) ◽  
pp. 155014772091782 ◽  
Author(s):  
Chunfang Yang ◽  
Yuhan Kang ◽  
Fenlin Liu ◽  
Xiaofeng Song ◽  
Jie Wang ◽  
...  
Keyword(s):  
Color Image ◽  
Adaptive Steganography ◽  
Potential Threat ◽  
Sensitive Data ◽  
Image Steganalysis ◽  
Feature Based ◽  
Occurrence Matrix ◽  
Model Features ◽  
Color Image Steganography ◽  
The Internet Of Things

It is a potential threat to persons and companies to reveal private or company-sensitive data through the Internet of Things by the color image steganography. The existing rich model features for color image steganalysis fail to utilize the fact that the content-adaptive steganography changes the pixels in complex textured regions with higher possibility. Therefore, this article proposes a variant of spatial rich model feature based on the embedding change probabilities in differential channels. The proposed feature is extracted from the residuals in the differential channels to reduce the image content information and enhance the stego signals significantly. Then, the embedding change probability of each element in the differential channels is added to the corresponding co-occurrence matrix bin to emphasize the interference of the residuals in textured regions to the improved co-occurrence matrix feature. The experimental results show that the proposed feature can significantly improve the detection performances for the WOW and S-UNIWARD steganography, especially when the payload size is small. For example, when the payload size is 0.05 bpp, the detection errors can be reduced respectively by 5.20% and 4.90% for WOW and S-UNIWARD by concatenating the proposed feature to the color rich model feature CRMQ1.

scholarly journals P14.32 Spatial discrepancies between FET PET and conventional MRI in patients with newly diagnosed glioblastoma

2019 ◽  
Vol 21 (Supplement_3) ◽  
pp. iii74-iii74
Author(s):  
P Lohmann ◽  
P Stavrinou ◽  
K Lipke ◽  
E K Bauer ◽  
G Ceccon ◽  
...  
Keyword(s):  
Amino Acid ◽  
Tumor Volume ◽  
Newly Diagnosed ◽  
Similarity Coefficients ◽  
Fet Pet ◽  
Spatial Similarity ◽  
Conventional Mri ◽  
Fluid Attenuated Inversion Recovery ◽  
Amino Acid Pet ◽  
Newly Diagnosed Glioblastoma

Abstract BACKGROUND In patients with glioblastoma, the tissue showing contrast enhancement (CE) in MRI is usually the target for resection or radiotherapy. However, the solid tumor mass typically extends beyond the area of CE. Amino acid PET can detect tumor parts that show no CE. We systematically investigated tumor volumes delineated by amino acid PET and MRI in newly diagnosed, untreated glioblastoma patients. MATERIAL AND METHODS Preoperatively, 50 patients with subsequently neuropathologically confirmed glioblastoma underwent O-(2-[18F]-fluoroethyl)-L-tyrosine (FET) PET, fluid-attenuated inversion recovery (FLAIR), and CE MRI. Areas of CE were manually delineated. FET PET tumor volumes were segmented using a tumor-to-brain ratio ≥ 1.6. The percentage of overlapping volumes (OV), as well as Dice and Jaccard spatial similarity coefficients (DSC; JSC), were calculated. FLAIR images were evaluated visually. RESULTS In 86% of patients (n = 43), the FET PET tumor volume was significantly larger than the volume of CE (21.5 ± 14.3 mL vs. 9.4 ± 11.3 mL; P < 0.001). Forty patients (80%) showed both an increased uptake of FET and CE. In these 40 patients, the spatial similarity between FET and CE was low (mean DSC, 0.39 ± 0.21; mean JSC, 0.26 ± 0.16). Ten patients (20%) showed no CE, and one of these patients showed no FET uptake. In 10% of patients (n = 5), increased FET uptake was present outside of areas of FLAIR hyperintensity. CONCLUSION Our results show that the metabolically active tumor volume delineated by FET PET is significantly larger than tumor volume delineated by CE. The data strongly suggest that the information derived from FET PET should be integrated into the management of newly diagnosed glioblastoma patients. FUNDING This work was supported by the Wilhelm-Sander Stiftung, Germany

scholarly journals Case Report: Detection of Symptomatic Treatment-Related Changes in a Patient With Anaplastic Oligodendroglioma Using FET PET

2021 ◽  
Vol 11 ◽  
Author(s):  
Elena Katharina Bauer ◽  
Jan-Michael Werner ◽  
Gereon R. Fink ◽  
Karl-Josef Langen ◽  
Norbert Galldiks
Keyword(s):  
Clinical Decision Making ◽  
Systemic Treatment ◽  
Clinical Information ◽  
Symptomatic Treatment ◽  
Clinical Decision ◽  
Anaplastic Oligodendroglioma ◽  
Mri Findings ◽  
Fet Pet ◽  
Conventional Mri ◽  
Amino Acid Pet

Following local and systemic treatment of gliomas, the differentiation between glioma relapse and treatment-related changes such as pseudoprogression or radiation necrosis using conventional MRI is limited. To overcome this limitation, various amino acid PET tracers such as O-[2-(18F)-fluoroethyl]-L-tyrosine (FET) are increasingly used and provide valuable additional clinical information. We here report neuroimaging findings in a clincally symptomatic 53-year-old woman with a recurrent anaplastic oligodendroglioma with MRI findings highly suspicious for tumor progression. In contrast, FET PET imaging suggested treatment-related changes considerably earlier than the regression of contrast enhancement on MRI. In patients with oligodendroglioma, the phenomenon of symptomatic treatment-related changes is not well described, making these imaging findings unique and important for clinical decision-making.

scholarly journals Repeatability and Comparability of the Galilei-G4 and Cassini in Measuring Corneal Power and Astigmatism in Normal and Post-Refractive Surgery Eyes

2021 ◽  
Author(s):  
Mohamed Mohamed ◽  
Mahmood Khan ◽  
Amritha Kanakamedala ◽  
Isha Gupta ◽  
Li Wang ◽  
...  
Keyword(s):  
Refractive Surgery ◽  
Intraclass Correlation ◽  
Corneal Astigmatism ◽  
Corneal Power ◽  
History Of ◽  
The Mean ◽  
Age Range ◽  
High Repeatability ◽  
Posterior Corneal Astigmatism ◽  
Total Corneal Astigmatism

Abstract PURPOSE To assess the repeatability and comparability of the Galilei G4 versus the Cassini topographer in post-refractive eyes and in normal eyes, including older patients representative of an initial cataract evaluation. METHODS Simulated keratometric (simK), total corneal and posterior corneal power and astigmatism were evaluated in both post-refractive and normal eyes. Repeatability was measured by calculating within-subject standard deviation (Sw), coefficient of variation (CoV), and intraclass correlation coefficient (ICC). Vector analyses and Bland-Altman plots were employed to assess agreement between devices. RESULTS We studied 32 subjects with a history of refractive surgery and 32 subjects without a history of refractive surgery undergoing cataract surgery. The mean age was 55 ± 18.5 years and the age range was 21.5 to 91.5 years. In non-refractive and post-refractive eyes, the ICC was > 0.9 (P < .001) for all corneal powers and for simK and total corneal astigmatism for both analyzers. The ICC for posterior corneal astigmatism magnitude using the Galilei was 0.62 and 0.67 and for the Cassini 0.55 and 0.38 in normal and post-refractive eyes, respectively. CONCLUSIONS In both post-refractive and normal eyes, the Galilei G4 and Cassini analyzers have high repeatability in simK, total, and posterior corneal power and low repeatability for posterior corneal astigmatism.

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