The Experts below are selected from a list of 17214 Experts worldwide ranked by ideXlab platform
Sandra Nuyts - One of the best experts on this subject based on the ideXlab platform.
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dose painting in radiotherapy for head and neck squamous cell carcinoma value of repeated functional imaging with 18f fdg pet 18f fluoromisonidazole pet diffusion weighted MRI and Dynamic contrast enhanced MRI
The Journal of Nuclear Medicine, 2009Co-Authors: Piet Dirix, Vincent Vandecaveye, Frederik De Keyzer, Sigrid Stroobants, Robert Hermans, Sandra NuytsAbstract:The purpose of this work was to evaluate the potential of functional imaging with 18F-FDG PET, 18F-fluoromisonidazole PET, diffusion-weighted MRI, and Dynamic Contrast-Enhanced MRI to provide an appropriate and reliable biologic target for dose painting in radiotherapy for head and neck squamous cell carcinoma (HNSCC). Methods: Fifteen patients with locally advanced HNSCC, treated with concomitant chemoradiotherapy, were prospectively enrolled in a bioimaging protocol. Sequential PET (18F-FDG and 18F-fluoromisonidazole) and MRI (T1, T2, Dynamic enhanced, and diffusion-weighted sequences) were performed before, during, and after radiotherapy. Results: Median follow-up was 30.7 mo (range, 6.3–56.3 mo); in 7 patients, disease recurred. Disease-free survival correlated negatively with the maximum tissue-to-blood 18F-fluoromisonidazole ratio (T/Bmax) on the baseline 18F-fluoromisonidazole scan (P = 0.04), with the size of the initial hypoxic volume (P = 0.04), and with T/Bmax on the 18F-fluoromisonidazole scan during treatment (P = 0.02). All locoregional recurrences were within the 18F-FDG–avid regions on baseline 18F-FDG PET; 3 recurrences mapped outside the hypoxic volume on baseline 18F-fluoromisonidazole PET. Lesions (primary tumor and lymph nodes) where a locoregional recurrence developed during follow-up had significantly lower apparent diffusion coefficients on diffusion-weighted MRI during week 4 of radiotherapy (0.0013 vs. 0.0018 mm2/s, P = 0.01) and at 3 wk after treatment (0.0014 vs. 0.0018 mm2/s, P = 0.01) and a significantly higher initial slope on baseline Dynamic enhanced MRI (26.2 vs. 17.5/s, P = 0.03) than did lesions that remained controlled. Conclusion: These results confirm the added value of 18F-FDG PET and 18F-fluoromisonidazole PET for radiotherapy planning of HNSCC and suggest the potential of diffusion-weighted and Dynamic enhanced MRI for dose painting and early response assessment.
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dose painting in radiotherapy for head and neck squamous cell carcinoma value of repeated functional imaging with 18f fdg pet 18f fluoromisonidazole pet diffusion weighted MRI and Dynamic contrast enhanced MRI
The Journal of Nuclear Medicine, 2009Co-Authors: Piet Dirix, Vincent Vandecaveye, Frederik De Keyzer, Sigrid Stroobants, Robert Hermans, Sandra NuytsAbstract:UNLABELLED The purpose of this work was to evaluate the potential of functional imaging with (18)F-FDG PET, (18)F-fluoromisonidazole PET, diffusion-weighted MRI, and Dynamic Contrast-Enhanced MRI to provide an appropriate and reliable biologic target for dose painting in radiotherapy for head and neck squamous cell carcinoma (HNSCC). METHODS Fifteen patients with locally advanced HNSCC, treated with concomitant chemoradiotherapy, were prospectively enrolled in a bioimaging protocol. Sequential PET ((18)F-FDG and (18)F-fluoromisonidazole) and MRI (T1, T2, Dynamic enhanced, and diffusion-weighted sequences) were performed before, during, and after radiotherapy. RESULTS Median follow-up was 30.7 mo (range, 6.3-56.3 mo); in 7 patients, disease recurred. Disease-free survival correlated negatively with the maximum tissue-to-blood (18)F-fluoromisonidazole ratio (T/B(max)) on the baseline (18)F-fluoromisonidazole scan (P = 0.04), with the size of the initial hypoxic volume (P = 0.04), and with T/B(max) on the (18)F-fluoromisonidazole scan during treatment (P = 0.02). All locoregional recurrences were within the (18)F-FDG-avid regions on baseline (18)F-FDG PET; 3 recurrences mapped outside the hypoxic volume on baseline (18)F-fluoromisonidazole PET. Lesions (primary tumor and lymph nodes) where a locoregional recurrence developed during follow-up had significantly lower apparent diffusion coefficients on diffusion-weighted MRI during week 4 of radiotherapy (0.0013 vs. 0.0018 mm(2)/s, P = 0.01) and at 3 wk after treatment (0.0014 vs. 0.0018 mm(2)/s, P = 0.01) and a significantly higher initial slope on baseline Dynamic enhanced MRI (26.2 vs. 17.5/s, P = 0.03) than did lesions that remained controlled. CONCLUSION These results confirm the added value of (18)F-FDG PET and (18)F-fluoromisonidazole PET for radiotherapy planning of HNSCC and suggest the potential of diffusion-weighted and Dynamic enhanced MRI for dose painting and early response assessment.
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dose painting in radiotherapy for head and neck squamous cell carcinoma value of repeated functional imaging with 18f fdg pet 18f fluoromisonidazole pet diffusion weighted MRI and Dynamic contrast enhanced MRI
The Journal of Nuclear Medicine, 2009Co-Authors: Piet Dirix, Vincent Vandecaveye, Frederik De Keyzer, Sigrid Stroobants, Robert Hermans, Sandra NuytsAbstract:The purpose of this work was to evaluate the potential of functional imaging with 18 F-FDG PET, 18 F-fluoromisonidazole PET, diffusion-weighted MRI, and Dynamic Contrast-Enhanced MRI to provide an appropriate and reliable biologic target for dose painting in radiotherapy for head and neck squamous cell carcinoma (HNSCC). Methods: Fifteen patients with locally advanced HNSCC, treated with concomitant chemoradiotherapy, were prospectively enrolled in a bioimaging protocol. Sequential PET ( 18 F-FDG and 18 F -fluoromisonidazole) and MRI (T1, T2, Dynamic enhanced, and diffusion-weighted sequences) were performed before, during, and after radiotherapy. Results: Median follow-up was 30.7 mo (range, 6.3-56.3 mo); in 7 patients, disease recurred. Disease-free survival correlated negatively with the maximum tissue-to-blood 18 F-fluoromisonidazole ratio (T/B max ) on the baseline 18 F-fluoromisonidazole scan (P = 0.04), with the size of the initial hypoxic volume (P = 0.04), and with T/B max on the 18 F-fluoromisonidazole scan during treatment (P = 0.02). All locoregional recurrences were within the 18 F-FDG-avid regions on baseline 18 F-FDG PET; 3 recurrences mapped outside the hypoxic volume on baseline 18 F -fluoromisonidazole PET. Lesions (primary tumor and lymph nodes) where a locoregional recurrence developed during follow-up had significantly lower apparent diffusion coefficients on diffusion-weighted MRI during week 4 of radiotherapy (0.0013 vs. 0.0018 mm 2 /s, P = 0.01) and at 3 wk after treatment (0.0014 vs. 0.0018 mm 2 /s, P = 0.01) and a significantly higher initial slope on baseline Dynamic enhanced MRI (26.2 vs. 17.5/s, P = 0.03) than did lesions that remained controlled. Conclusion: These results confirm the added value of 18 F-FDG PET and 18 F -fluoromisonidazole PET for radiotherapy planning of HNSCC and suggest the potential of diffusion-weighted and Dynamic enhanced MRI for dose painting and early response assessment.
Alan Jackson - One of the best experts on this subject based on the ideXlab platform.
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mitotic activity in glioblastoma correlates with estimated extravascular extracellular space derived from Dynamic contrast enhanced mr imaging
American Journal of Neuroradiology, 2016Co-Authors: Samantha J Mills, D Du Plessis, P Pal, Gerard Thompson, G Buonacorrsi, Calvin Soh, G J Parker, Alan JacksonAbstract:BACKGROUND AND PURPOSE: A number of parameters derived from Dynamic Contrast-Enhanced MR imaging and separate histologic features have been identified as potential prognosticators in high-grade glioma. This study evaluated the relationships between Dynamic Contrast-Enhanced MRI–derived parameters and histologic features in glioblastoma multiforme. MATERIALS AND METHODS: Twenty-eight patients with newly presenting glioblastoma multiforme underwent preoperative imaging (conventional imaging and T1 Dynamic Contrast-Enhanced MRI). Parametric maps of the initial area under the contrast agent concentration curve, contrast transfer coefficient, estimate of volume of the extravascular extracellular space, and estimate of blood plasma volume were generated, and the enhancing fraction was calculated. Surgical specimens were used to assess subtype and were graded (World Health Organization classification system) and were assessed for necrosis, cell density, cellular atypia, mitotic activity, and overall vascularity scores. Quantitative assessment of endothelial surface area, vascular surface area, and a vascular profile count were made by using CD34 immunostaining. The relationships between MR imaging parameters and histopathologic features were examined. RESULTS: High values of contrast transfer coefficient were associated with the presence of frank necrosis (P = .005). High values of the estimate of volume of the extravascular extracellular space were associated with a fibrillary histologic pattern (P CONCLUSIONS: A correlation between the estimate of volume of the extravascular extracellular space and mitotic activity is reported. Further work is warranted to establish how Dynamic Contrast-Enhanced MRI parameters relate to more quantitative histologic measurements, including markers of proliferation and measures of vascular endothelial growth factor expression.
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Dynamic contrast enhanced MRI in clinical trials of antivascular therapies
Nature Reviews Clinical Oncology, 2012Co-Authors: James P B Oconnor, Caleb Roberts, Alan Jackson, Geoff J M Parker, Gordon C JaysonAbstract:About 100 early-phase clinical trials and investigator-led studies of targeted antivascular therapies--both anti-angiogenic and vascular-targeting agents--have reported data derived from T1-weighted Dynamic Contrast-Enhanced (DCE)-MRI. However, the role of DCE-MRI for decision making during the drug-development process remains controversial. Despite well-documented guidelines on image acquisition and analysis, several key questions concerning the role of this technique in early-phase trial design remain unanswered. This Review describes studies of single-agent antivascular therapies, in which DCE-MRI parameters are incorporated as pharmacoDynamic biomarkers. We discuss whether these parameters, such as volume transfer constant (K(trans)), are reproducible and reliable biomarkers of both drug efficacy and proof of concept, and whether they assist in dose selection and drug scheduling for subsequent phase II trials. Emerging evidence indicates that multiparametric analysis of DCE-MRI data offers greater insight into the mechanism of drug action than studies measuring a single parameter, such as K(trans). We also provide an overview of current data and appraise the future directions of this technique in oncology trials. Finally, major hurdles in imaging biomarker development, validation and qualification that hinder a wide application of DCE-MRI techniques in clinical trials are addressed.
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quantifying spatial heterogeneity in Dynamic contrast enhanced MRI parameter maps
Magnetic Resonance in Medicine, 2009Co-Authors: C J Rose, Giovanni A Buonaccorsi, James P B Oconnor, Caleb Roberts, Susan Cheung, Yvonne Watson, Samantha J Mills, Sha Zhao, Brandon Whitcher, Alan JacksonAbstract:Dynamic Contrast-Enhanced MRI is becoming a standard tool for imaging-based trials of anti-vascular/angiogenic agents in cancer. So far, however, biomarkers derived from DCE-MRI parameter maps have largely neglected the fact that the maps have spatial structure and instead focussed on distributional summary statistics. Such statistics - e.g., biomarkers based on median values - neglect the spatial arrangement of parameters, which may carry important diagnostic and prognostic information. This article describes two types of heterogeneity biomarker that are sensitive to both parameter values and their spatial arrangement. Methods based on Renyi fractal dimensions and geometrical properties are developed, both of which attempt to describe the complexity of DCE-MRI parameter maps. Experiments using simulated data show that the proposed biomarkers are sensitive to changes that distribution-based summary statistics cannot detect and demonstrate that heterogeneity biomarkers could be applied in the drug trial setting. An experiment using 23 DCE-MRI parameter maps of gliomas - a class of tumour that is graded on the basis of heterogeneity - shows that the proposed heterogeneity biomarkers are able to differentiate between low- and high-grade tumours. Magn Reson Med, 2009. © 2009 Wiley-Liss, Inc.
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quantifying spatial heterogeneity in Dynamic contrast enhanced MRI parameter maps
Magnetic Resonance in Medicine, 2009Co-Authors: C J Rose, Giovanni A Buonaccorsi, James P B Oconnor, Caleb Roberts, Susan Cheung, Yvonne Watson, Samantha J Mills, Sha Zhao, Brandon Whitcher, Alan JacksonAbstract:Dynamic Contrast-Enhanced MRI is becoming a standard tool for imaging-based trials of anti-vascular/angiogenic agents in cancer. So far, however, biomarkers derived from DCE-MRI parameter maps have largely neglected the fact that the maps have spatial structure and instead focussed on distributional summary statistics. Such statistics - e.g., biomarkers based on median values - neglect the spatial arrangement of parameters, which may carry important diagnostic and prognostic information. This article describes two types of heterogeneity biomarker that are sensitive to both parameter values and their spatial arrangement. Methods based on Renyi fractal dimensions and geometrical properties are developed, both of which attempt to describe the complexity of DCE-MRI parameter maps. Experiments using simulated data show that the proposed biomarkers are sensitive to changes that distribution-based summary statistics cannot detect and demonstrate that heterogeneity biomarkers could be applied in the drug trial setting. An experiment using 23 DCE-MRI parameter maps of gliomas - a class of tumour that is graded on the basis of heterogeneity - shows that the proposed heterogeneity biomarkers are able to differentiate between low- and high-grade tumours. Magn Reson Med, 2009. © 2009 Wiley-Liss, Inc.
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modeling of contrast agent kinetics in the lung using t1 weighted Dynamic contrast enhanced MRI
Magnetic Resonance in Medicine, 2009Co-Authors: Josephine H Naish, David L Buckley, Alan Jackson, Lucy E Kershaw, John C Waterton, Geoffrey J M ParkerAbstract:Assessment of perfusion and capillary permeability is important in both malignant and nonmalignant lung disease. Kinetic modeling of T(1)-weighted Dynamic Contrast-Enhanced MRI (DCE-MRI) data may provide such an assessment. This study establishes the feasibility and interrelationship of kinetic modeling approaches designed to estimate microvascular properties in malignant and nonmalignant tissues of the lung. DCE-MRI data were acquired using a low molecular weight contrast agent with 4-sec temporal resolution in lung cancer patients. A model-free parameterization and three kinetic models of increasing complexity, each related to the classical Kety model, were applied. Comparison of an extended Kety model and the adiabatic approximation to the tissue homogeneity (AATH) model using Akaike's Information Criterion suggested that in most cases the best description of the lung tumor data is obtained using the AATH model. In the normal lung parenchyma the temporal resolution was insufficient to separate effects of flow and contrast agent leakage and in this case the extended Kety model yielded the best fit to the data.
Piet Dirix - One of the best experts on this subject based on the ideXlab platform.
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dose painting in radiotherapy for head and neck squamous cell carcinoma value of repeated functional imaging with 18f fdg pet 18f fluoromisonidazole pet diffusion weighted MRI and Dynamic contrast enhanced MRI
The Journal of Nuclear Medicine, 2009Co-Authors: Piet Dirix, Vincent Vandecaveye, Frederik De Keyzer, Sigrid Stroobants, Robert Hermans, Sandra NuytsAbstract:The purpose of this work was to evaluate the potential of functional imaging with 18F-FDG PET, 18F-fluoromisonidazole PET, diffusion-weighted MRI, and Dynamic Contrast-Enhanced MRI to provide an appropriate and reliable biologic target for dose painting in radiotherapy for head and neck squamous cell carcinoma (HNSCC). Methods: Fifteen patients with locally advanced HNSCC, treated with concomitant chemoradiotherapy, were prospectively enrolled in a bioimaging protocol. Sequential PET (18F-FDG and 18F-fluoromisonidazole) and MRI (T1, T2, Dynamic enhanced, and diffusion-weighted sequences) were performed before, during, and after radiotherapy. Results: Median follow-up was 30.7 mo (range, 6.3–56.3 mo); in 7 patients, disease recurred. Disease-free survival correlated negatively with the maximum tissue-to-blood 18F-fluoromisonidazole ratio (T/Bmax) on the baseline 18F-fluoromisonidazole scan (P = 0.04), with the size of the initial hypoxic volume (P = 0.04), and with T/Bmax on the 18F-fluoromisonidazole scan during treatment (P = 0.02). All locoregional recurrences were within the 18F-FDG–avid regions on baseline 18F-FDG PET; 3 recurrences mapped outside the hypoxic volume on baseline 18F-fluoromisonidazole PET. Lesions (primary tumor and lymph nodes) where a locoregional recurrence developed during follow-up had significantly lower apparent diffusion coefficients on diffusion-weighted MRI during week 4 of radiotherapy (0.0013 vs. 0.0018 mm2/s, P = 0.01) and at 3 wk after treatment (0.0014 vs. 0.0018 mm2/s, P = 0.01) and a significantly higher initial slope on baseline Dynamic enhanced MRI (26.2 vs. 17.5/s, P = 0.03) than did lesions that remained controlled. Conclusion: These results confirm the added value of 18F-FDG PET and 18F-fluoromisonidazole PET for radiotherapy planning of HNSCC and suggest the potential of diffusion-weighted and Dynamic enhanced MRI for dose painting and early response assessment.
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dose painting in radiotherapy for head and neck squamous cell carcinoma value of repeated functional imaging with 18f fdg pet 18f fluoromisonidazole pet diffusion weighted MRI and Dynamic contrast enhanced MRI
The Journal of Nuclear Medicine, 2009Co-Authors: Piet Dirix, Vincent Vandecaveye, Frederik De Keyzer, Sigrid Stroobants, Robert Hermans, Sandra NuytsAbstract:UNLABELLED The purpose of this work was to evaluate the potential of functional imaging with (18)F-FDG PET, (18)F-fluoromisonidazole PET, diffusion-weighted MRI, and Dynamic Contrast-Enhanced MRI to provide an appropriate and reliable biologic target for dose painting in radiotherapy for head and neck squamous cell carcinoma (HNSCC). METHODS Fifteen patients with locally advanced HNSCC, treated with concomitant chemoradiotherapy, were prospectively enrolled in a bioimaging protocol. Sequential PET ((18)F-FDG and (18)F-fluoromisonidazole) and MRI (T1, T2, Dynamic enhanced, and diffusion-weighted sequences) were performed before, during, and after radiotherapy. RESULTS Median follow-up was 30.7 mo (range, 6.3-56.3 mo); in 7 patients, disease recurred. Disease-free survival correlated negatively with the maximum tissue-to-blood (18)F-fluoromisonidazole ratio (T/B(max)) on the baseline (18)F-fluoromisonidazole scan (P = 0.04), with the size of the initial hypoxic volume (P = 0.04), and with T/B(max) on the (18)F-fluoromisonidazole scan during treatment (P = 0.02). All locoregional recurrences were within the (18)F-FDG-avid regions on baseline (18)F-FDG PET; 3 recurrences mapped outside the hypoxic volume on baseline (18)F-fluoromisonidazole PET. Lesions (primary tumor and lymph nodes) where a locoregional recurrence developed during follow-up had significantly lower apparent diffusion coefficients on diffusion-weighted MRI during week 4 of radiotherapy (0.0013 vs. 0.0018 mm(2)/s, P = 0.01) and at 3 wk after treatment (0.0014 vs. 0.0018 mm(2)/s, P = 0.01) and a significantly higher initial slope on baseline Dynamic enhanced MRI (26.2 vs. 17.5/s, P = 0.03) than did lesions that remained controlled. CONCLUSION These results confirm the added value of (18)F-FDG PET and (18)F-fluoromisonidazole PET for radiotherapy planning of HNSCC and suggest the potential of diffusion-weighted and Dynamic enhanced MRI for dose painting and early response assessment.
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dose painting in radiotherapy for head and neck squamous cell carcinoma value of repeated functional imaging with 18f fdg pet 18f fluoromisonidazole pet diffusion weighted MRI and Dynamic contrast enhanced MRI
The Journal of Nuclear Medicine, 2009Co-Authors: Piet Dirix, Vincent Vandecaveye, Frederik De Keyzer, Sigrid Stroobants, Robert Hermans, Sandra NuytsAbstract:The purpose of this work was to evaluate the potential of functional imaging with 18 F-FDG PET, 18 F-fluoromisonidazole PET, diffusion-weighted MRI, and Dynamic Contrast-Enhanced MRI to provide an appropriate and reliable biologic target for dose painting in radiotherapy for head and neck squamous cell carcinoma (HNSCC). Methods: Fifteen patients with locally advanced HNSCC, treated with concomitant chemoradiotherapy, were prospectively enrolled in a bioimaging protocol. Sequential PET ( 18 F-FDG and 18 F -fluoromisonidazole) and MRI (T1, T2, Dynamic enhanced, and diffusion-weighted sequences) were performed before, during, and after radiotherapy. Results: Median follow-up was 30.7 mo (range, 6.3-56.3 mo); in 7 patients, disease recurred. Disease-free survival correlated negatively with the maximum tissue-to-blood 18 F-fluoromisonidazole ratio (T/B max ) on the baseline 18 F-fluoromisonidazole scan (P = 0.04), with the size of the initial hypoxic volume (P = 0.04), and with T/B max on the 18 F-fluoromisonidazole scan during treatment (P = 0.02). All locoregional recurrences were within the 18 F-FDG-avid regions on baseline 18 F-FDG PET; 3 recurrences mapped outside the hypoxic volume on baseline 18 F -fluoromisonidazole PET. Lesions (primary tumor and lymph nodes) where a locoregional recurrence developed during follow-up had significantly lower apparent diffusion coefficients on diffusion-weighted MRI during week 4 of radiotherapy (0.0013 vs. 0.0018 mm 2 /s, P = 0.01) and at 3 wk after treatment (0.0014 vs. 0.0018 mm 2 /s, P = 0.01) and a significantly higher initial slope on baseline Dynamic enhanced MRI (26.2 vs. 17.5/s, P = 0.03) than did lesions that remained controlled. Conclusion: These results confirm the added value of 18 F-FDG PET and 18 F -fluoromisonidazole PET for radiotherapy planning of HNSCC and suggest the potential of diffusion-weighted and Dynamic enhanced MRI for dose painting and early response assessment.
Vincent Vandecaveye - One of the best experts on this subject based on the ideXlab platform.
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dose painting in radiotherapy for head and neck squamous cell carcinoma value of repeated functional imaging with 18f fdg pet 18f fluoromisonidazole pet diffusion weighted MRI and Dynamic contrast enhanced MRI
The Journal of Nuclear Medicine, 2009Co-Authors: Piet Dirix, Vincent Vandecaveye, Frederik De Keyzer, Sigrid Stroobants, Robert Hermans, Sandra NuytsAbstract:UNLABELLED The purpose of this work was to evaluate the potential of functional imaging with (18)F-FDG PET, (18)F-fluoromisonidazole PET, diffusion-weighted MRI, and Dynamic Contrast-Enhanced MRI to provide an appropriate and reliable biologic target for dose painting in radiotherapy for head and neck squamous cell carcinoma (HNSCC). METHODS Fifteen patients with locally advanced HNSCC, treated with concomitant chemoradiotherapy, were prospectively enrolled in a bioimaging protocol. Sequential PET ((18)F-FDG and (18)F-fluoromisonidazole) and MRI (T1, T2, Dynamic enhanced, and diffusion-weighted sequences) were performed before, during, and after radiotherapy. RESULTS Median follow-up was 30.7 mo (range, 6.3-56.3 mo); in 7 patients, disease recurred. Disease-free survival correlated negatively with the maximum tissue-to-blood (18)F-fluoromisonidazole ratio (T/B(max)) on the baseline (18)F-fluoromisonidazole scan (P = 0.04), with the size of the initial hypoxic volume (P = 0.04), and with T/B(max) on the (18)F-fluoromisonidazole scan during treatment (P = 0.02). All locoregional recurrences were within the (18)F-FDG-avid regions on baseline (18)F-FDG PET; 3 recurrences mapped outside the hypoxic volume on baseline (18)F-fluoromisonidazole PET. Lesions (primary tumor and lymph nodes) where a locoregional recurrence developed during follow-up had significantly lower apparent diffusion coefficients on diffusion-weighted MRI during week 4 of radiotherapy (0.0013 vs. 0.0018 mm(2)/s, P = 0.01) and at 3 wk after treatment (0.0014 vs. 0.0018 mm(2)/s, P = 0.01) and a significantly higher initial slope on baseline Dynamic enhanced MRI (26.2 vs. 17.5/s, P = 0.03) than did lesions that remained controlled. CONCLUSION These results confirm the added value of (18)F-FDG PET and (18)F-fluoromisonidazole PET for radiotherapy planning of HNSCC and suggest the potential of diffusion-weighted and Dynamic enhanced MRI for dose painting and early response assessment.
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dose painting in radiotherapy for head and neck squamous cell carcinoma value of repeated functional imaging with 18f fdg pet 18f fluoromisonidazole pet diffusion weighted MRI and Dynamic contrast enhanced MRI
The Journal of Nuclear Medicine, 2009Co-Authors: Piet Dirix, Vincent Vandecaveye, Frederik De Keyzer, Sigrid Stroobants, Robert Hermans, Sandra NuytsAbstract:The purpose of this work was to evaluate the potential of functional imaging with 18F-FDG PET, 18F-fluoromisonidazole PET, diffusion-weighted MRI, and Dynamic Contrast-Enhanced MRI to provide an appropriate and reliable biologic target for dose painting in radiotherapy for head and neck squamous cell carcinoma (HNSCC). Methods: Fifteen patients with locally advanced HNSCC, treated with concomitant chemoradiotherapy, were prospectively enrolled in a bioimaging protocol. Sequential PET (18F-FDG and 18F-fluoromisonidazole) and MRI (T1, T2, Dynamic enhanced, and diffusion-weighted sequences) were performed before, during, and after radiotherapy. Results: Median follow-up was 30.7 mo (range, 6.3–56.3 mo); in 7 patients, disease recurred. Disease-free survival correlated negatively with the maximum tissue-to-blood 18F-fluoromisonidazole ratio (T/Bmax) on the baseline 18F-fluoromisonidazole scan (P = 0.04), with the size of the initial hypoxic volume (P = 0.04), and with T/Bmax on the 18F-fluoromisonidazole scan during treatment (P = 0.02). All locoregional recurrences were within the 18F-FDG–avid regions on baseline 18F-FDG PET; 3 recurrences mapped outside the hypoxic volume on baseline 18F-fluoromisonidazole PET. Lesions (primary tumor and lymph nodes) where a locoregional recurrence developed during follow-up had significantly lower apparent diffusion coefficients on diffusion-weighted MRI during week 4 of radiotherapy (0.0013 vs. 0.0018 mm2/s, P = 0.01) and at 3 wk after treatment (0.0014 vs. 0.0018 mm2/s, P = 0.01) and a significantly higher initial slope on baseline Dynamic enhanced MRI (26.2 vs. 17.5/s, P = 0.03) than did lesions that remained controlled. Conclusion: These results confirm the added value of 18F-FDG PET and 18F-fluoromisonidazole PET for radiotherapy planning of HNSCC and suggest the potential of diffusion-weighted and Dynamic enhanced MRI for dose painting and early response assessment.
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dose painting in radiotherapy for head and neck squamous cell carcinoma value of repeated functional imaging with 18f fdg pet 18f fluoromisonidazole pet diffusion weighted MRI and Dynamic contrast enhanced MRI
The Journal of Nuclear Medicine, 2009Co-Authors: Piet Dirix, Vincent Vandecaveye, Frederik De Keyzer, Sigrid Stroobants, Robert Hermans, Sandra NuytsAbstract:The purpose of this work was to evaluate the potential of functional imaging with 18 F-FDG PET, 18 F-fluoromisonidazole PET, diffusion-weighted MRI, and Dynamic Contrast-Enhanced MRI to provide an appropriate and reliable biologic target for dose painting in radiotherapy for head and neck squamous cell carcinoma (HNSCC). Methods: Fifteen patients with locally advanced HNSCC, treated with concomitant chemoradiotherapy, were prospectively enrolled in a bioimaging protocol. Sequential PET ( 18 F-FDG and 18 F -fluoromisonidazole) and MRI (T1, T2, Dynamic enhanced, and diffusion-weighted sequences) were performed before, during, and after radiotherapy. Results: Median follow-up was 30.7 mo (range, 6.3-56.3 mo); in 7 patients, disease recurred. Disease-free survival correlated negatively with the maximum tissue-to-blood 18 F-fluoromisonidazole ratio (T/B max ) on the baseline 18 F-fluoromisonidazole scan (P = 0.04), with the size of the initial hypoxic volume (P = 0.04), and with T/B max on the 18 F-fluoromisonidazole scan during treatment (P = 0.02). All locoregional recurrences were within the 18 F-FDG-avid regions on baseline 18 F-FDG PET; 3 recurrences mapped outside the hypoxic volume on baseline 18 F -fluoromisonidazole PET. Lesions (primary tumor and lymph nodes) where a locoregional recurrence developed during follow-up had significantly lower apparent diffusion coefficients on diffusion-weighted MRI during week 4 of radiotherapy (0.0013 vs. 0.0018 mm 2 /s, P = 0.01) and at 3 wk after treatment (0.0014 vs. 0.0018 mm 2 /s, P = 0.01) and a significantly higher initial slope on baseline Dynamic enhanced MRI (26.2 vs. 17.5/s, P = 0.03) than did lesions that remained controlled. Conclusion: These results confirm the added value of 18 F-FDG PET and 18 F -fluoromisonidazole PET for radiotherapy planning of HNSCC and suggest the potential of diffusion-weighted and Dynamic enhanced MRI for dose painting and early response assessment.
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diffusion weighted MRI provides additional value to conventional Dynamic contrast enhanced MRI for detection of hepatocellular carcinoma
European Radiology, 2009Co-Authors: Vincent Vandecaveye, Frederik De Keyzer, Chris Verslype, Katya Op De Beeck, Mina Komuta, Baki Topal, I Roebben, Didier Bielen, Tania Roskams, Frederik NevensAbstract:The purpose of this study was to evaluate the accuracy of diffusion-weighted magnetic resonance imaging (DW-MRI) in differentiating HCC from benign cirrhotic lesions compared with conventional Dynamic Contrast-Enhanced MRI. Fifty-five patients with cirrhosis underwent conventional and DW-MRI at 1.5 Tesla. Signal intensity ratios (SIratio) of solid liver lesions to adjacent hepatic parenchyma were measured for b0, b100, b600 and b1000, and the apparent diffusion coefficients (ADC) were calculated. In 27 patients, imaging results were compared to histopathology, and in 28 patients, to imaging follow-up. Based on predetermined thresholds, sensitivity and specificity of DW-MRI and conventional MRI were compared. SIratio was significantly different between malignant and benign lesions at all b-values (P < 0.0001). No significant difference in ADC was seen (P = 0.47). For detection of malignant lesions, DW-MRI with b600-SIratio yielded a sensitivity of 95.2% compared to 80.6% for conventional MRI (P = 0.023) and a specificity of 82.7% compared to 65.4% (P = 0.064). The improved accuracy was most beneficial for differentiating malignant lesions smaller than 2 cm. DW-MRI with b600-SIratio improved the detection of small HCC and the differentiation of pseudotumoral lesions compared with conventional MRI.
Frederik De Keyzer - One of the best experts on this subject based on the ideXlab platform.
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dose painting in radiotherapy for head and neck squamous cell carcinoma value of repeated functional imaging with 18f fdg pet 18f fluoromisonidazole pet diffusion weighted MRI and Dynamic contrast enhanced MRI
The Journal of Nuclear Medicine, 2009Co-Authors: Piet Dirix, Vincent Vandecaveye, Frederik De Keyzer, Sigrid Stroobants, Robert Hermans, Sandra NuytsAbstract:UNLABELLED The purpose of this work was to evaluate the potential of functional imaging with (18)F-FDG PET, (18)F-fluoromisonidazole PET, diffusion-weighted MRI, and Dynamic Contrast-Enhanced MRI to provide an appropriate and reliable biologic target for dose painting in radiotherapy for head and neck squamous cell carcinoma (HNSCC). METHODS Fifteen patients with locally advanced HNSCC, treated with concomitant chemoradiotherapy, were prospectively enrolled in a bioimaging protocol. Sequential PET ((18)F-FDG and (18)F-fluoromisonidazole) and MRI (T1, T2, Dynamic enhanced, and diffusion-weighted sequences) were performed before, during, and after radiotherapy. RESULTS Median follow-up was 30.7 mo (range, 6.3-56.3 mo); in 7 patients, disease recurred. Disease-free survival correlated negatively with the maximum tissue-to-blood (18)F-fluoromisonidazole ratio (T/B(max)) on the baseline (18)F-fluoromisonidazole scan (P = 0.04), with the size of the initial hypoxic volume (P = 0.04), and with T/B(max) on the (18)F-fluoromisonidazole scan during treatment (P = 0.02). All locoregional recurrences were within the (18)F-FDG-avid regions on baseline (18)F-FDG PET; 3 recurrences mapped outside the hypoxic volume on baseline (18)F-fluoromisonidazole PET. Lesions (primary tumor and lymph nodes) where a locoregional recurrence developed during follow-up had significantly lower apparent diffusion coefficients on diffusion-weighted MRI during week 4 of radiotherapy (0.0013 vs. 0.0018 mm(2)/s, P = 0.01) and at 3 wk after treatment (0.0014 vs. 0.0018 mm(2)/s, P = 0.01) and a significantly higher initial slope on baseline Dynamic enhanced MRI (26.2 vs. 17.5/s, P = 0.03) than did lesions that remained controlled. CONCLUSION These results confirm the added value of (18)F-FDG PET and (18)F-fluoromisonidazole PET for radiotherapy planning of HNSCC and suggest the potential of diffusion-weighted and Dynamic enhanced MRI for dose painting and early response assessment.
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dose painting in radiotherapy for head and neck squamous cell carcinoma value of repeated functional imaging with 18f fdg pet 18f fluoromisonidazole pet diffusion weighted MRI and Dynamic contrast enhanced MRI
The Journal of Nuclear Medicine, 2009Co-Authors: Piet Dirix, Vincent Vandecaveye, Frederik De Keyzer, Sigrid Stroobants, Robert Hermans, Sandra NuytsAbstract:The purpose of this work was to evaluate the potential of functional imaging with 18F-FDG PET, 18F-fluoromisonidazole PET, diffusion-weighted MRI, and Dynamic Contrast-Enhanced MRI to provide an appropriate and reliable biologic target for dose painting in radiotherapy for head and neck squamous cell carcinoma (HNSCC). Methods: Fifteen patients with locally advanced HNSCC, treated with concomitant chemoradiotherapy, were prospectively enrolled in a bioimaging protocol. Sequential PET (18F-FDG and 18F-fluoromisonidazole) and MRI (T1, T2, Dynamic enhanced, and diffusion-weighted sequences) were performed before, during, and after radiotherapy. Results: Median follow-up was 30.7 mo (range, 6.3–56.3 mo); in 7 patients, disease recurred. Disease-free survival correlated negatively with the maximum tissue-to-blood 18F-fluoromisonidazole ratio (T/Bmax) on the baseline 18F-fluoromisonidazole scan (P = 0.04), with the size of the initial hypoxic volume (P = 0.04), and with T/Bmax on the 18F-fluoromisonidazole scan during treatment (P = 0.02). All locoregional recurrences were within the 18F-FDG–avid regions on baseline 18F-FDG PET; 3 recurrences mapped outside the hypoxic volume on baseline 18F-fluoromisonidazole PET. Lesions (primary tumor and lymph nodes) where a locoregional recurrence developed during follow-up had significantly lower apparent diffusion coefficients on diffusion-weighted MRI during week 4 of radiotherapy (0.0013 vs. 0.0018 mm2/s, P = 0.01) and at 3 wk after treatment (0.0014 vs. 0.0018 mm2/s, P = 0.01) and a significantly higher initial slope on baseline Dynamic enhanced MRI (26.2 vs. 17.5/s, P = 0.03) than did lesions that remained controlled. Conclusion: These results confirm the added value of 18F-FDG PET and 18F-fluoromisonidazole PET for radiotherapy planning of HNSCC and suggest the potential of diffusion-weighted and Dynamic enhanced MRI for dose painting and early response assessment.
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dose painting in radiotherapy for head and neck squamous cell carcinoma value of repeated functional imaging with 18f fdg pet 18f fluoromisonidazole pet diffusion weighted MRI and Dynamic contrast enhanced MRI
The Journal of Nuclear Medicine, 2009Co-Authors: Piet Dirix, Vincent Vandecaveye, Frederik De Keyzer, Sigrid Stroobants, Robert Hermans, Sandra NuytsAbstract:The purpose of this work was to evaluate the potential of functional imaging with 18 F-FDG PET, 18 F-fluoromisonidazole PET, diffusion-weighted MRI, and Dynamic Contrast-Enhanced MRI to provide an appropriate and reliable biologic target for dose painting in radiotherapy for head and neck squamous cell carcinoma (HNSCC). Methods: Fifteen patients with locally advanced HNSCC, treated with concomitant chemoradiotherapy, were prospectively enrolled in a bioimaging protocol. Sequential PET ( 18 F-FDG and 18 F -fluoromisonidazole) and MRI (T1, T2, Dynamic enhanced, and diffusion-weighted sequences) were performed before, during, and after radiotherapy. Results: Median follow-up was 30.7 mo (range, 6.3-56.3 mo); in 7 patients, disease recurred. Disease-free survival correlated negatively with the maximum tissue-to-blood 18 F-fluoromisonidazole ratio (T/B max ) on the baseline 18 F-fluoromisonidazole scan (P = 0.04), with the size of the initial hypoxic volume (P = 0.04), and with T/B max on the 18 F-fluoromisonidazole scan during treatment (P = 0.02). All locoregional recurrences were within the 18 F-FDG-avid regions on baseline 18 F-FDG PET; 3 recurrences mapped outside the hypoxic volume on baseline 18 F -fluoromisonidazole PET. Lesions (primary tumor and lymph nodes) where a locoregional recurrence developed during follow-up had significantly lower apparent diffusion coefficients on diffusion-weighted MRI during week 4 of radiotherapy (0.0013 vs. 0.0018 mm 2 /s, P = 0.01) and at 3 wk after treatment (0.0014 vs. 0.0018 mm 2 /s, P = 0.01) and a significantly higher initial slope on baseline Dynamic enhanced MRI (26.2 vs. 17.5/s, P = 0.03) than did lesions that remained controlled. Conclusion: These results confirm the added value of 18 F-FDG PET and 18 F -fluoromisonidazole PET for radiotherapy planning of HNSCC and suggest the potential of diffusion-weighted and Dynamic enhanced MRI for dose painting and early response assessment.
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diffusion weighted MRI provides additional value to conventional Dynamic contrast enhanced MRI for detection of hepatocellular carcinoma
European Radiology, 2009Co-Authors: Vincent Vandecaveye, Frederik De Keyzer, Chris Verslype, Katya Op De Beeck, Mina Komuta, Baki Topal, I Roebben, Didier Bielen, Tania Roskams, Frederik NevensAbstract:The purpose of this study was to evaluate the accuracy of diffusion-weighted magnetic resonance imaging (DW-MRI) in differentiating HCC from benign cirrhotic lesions compared with conventional Dynamic Contrast-Enhanced MRI. Fifty-five patients with cirrhosis underwent conventional and DW-MRI at 1.5 Tesla. Signal intensity ratios (SIratio) of solid liver lesions to adjacent hepatic parenchyma were measured for b0, b100, b600 and b1000, and the apparent diffusion coefficients (ADC) were calculated. In 27 patients, imaging results were compared to histopathology, and in 28 patients, to imaging follow-up. Based on predetermined thresholds, sensitivity and specificity of DW-MRI and conventional MRI were compared. SIratio was significantly different between malignant and benign lesions at all b-values (P < 0.0001). No significant difference in ADC was seen (P = 0.47). For detection of malignant lesions, DW-MRI with b600-SIratio yielded a sensitivity of 95.2% compared to 80.6% for conventional MRI (P = 0.023) and a specificity of 82.7% compared to 65.4% (P = 0.064). The improved accuracy was most beneficial for differentiating malignant lesions smaller than 2 cm. DW-MRI with b600-SIratio improved the detection of small HCC and the differentiation of pseudotumoral lesions compared with conventional MRI.
