References of "Balteau, Evelyne"
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See detailMultiparameter MRI quantification of microstructural tissue alterations in multiple sclerosis
LOMMERS, Emilie ULiege; Simon, Jessica ULiege; REUTER, Gilles ULiege et al

in NeuroImage: Clinical (2019), 23

Objectives: Conventional MRI is not sensitive to many pathological processes underpinning multiple sclerosis (MS) ongoing in normal appearing brain tissue (NABT). Quantitative MRI (qMRI) and a ... [more ▼]

Objectives: Conventional MRI is not sensitive to many pathological processes underpinning multiple sclerosis (MS) ongoing in normal appearing brain tissue (NABT). Quantitative MRI (qMRI) and a multiparameter mapping (MPM) protocol were used to simultaneously quantify magnetization transfer (MT) saturation, transverse relaxation rate R2* (1/T2*) and longitudinal relaxation rate R1 (1/T1), and assess differences in NABT microstructure between MS patients and healthy controls (HC). Methods: This prospective cross-sectional study involves 36 MS patients (20 females, 16 males; age range 22-63 years; 15 relapsing-remitting MS - RRMS; 21 primary or secondary progressive MS - PMS) and 36 age-matched HC (20 females, 16 males); age range 21-61 years). The qMRI maps are computed and segmented in lesions and 3 normal appearing cerebral tissue classes: normal appearing cortical grey matter (NACGM), normal appearing deep grey matter (NADGM), normal appearing white matter (NAWM). Individual median values are extracted for each tissue class and MR parameter. MANOVAs and stepwise regressions assess differences between patients and HC. Results: MS patients are characterized by a decrease in MT, R2* and R1 within NACGM (p < 0.0001) and NAWM (p < 0.0001). In NADGM, MT decreases (p < 0.0001) but R2* and R1 remain normal. These observations tend to be more pronounced in PMS. Quantitative MRI parameters are independent predictors of clinical status: EDSS is significantly related to R1 in NACGM and R2* in NADGM; the latter also predicts motor score. Cognitive score is best predicted by MT parameter within lesions. Conclusions: Multiparametric data on brain microstructure concord with the literature, predict clinical performance and suggest a diffuse reduction in myelin and/or iron content within NABT of MS patients. [less ▲]

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See detailTumor modifications recorded with IVIM and DCE-MRI after Neoadjuvant radiotherapy.
LALLEMAND, François ULiege; LEROI, Natacha ULiege; Bahri, Mohamed Ali ULiege et al

in Radiotherapy and Oncology (2019, April), 133(Supplement 1), 284-285

Purpose or Objective Neoadjuvant radiotherapy (NeoRT) improves tumor local control and facilitates tumor resection in many cancers. We hypothesized anti-cancer treatments (i.e. radiotherapy) modify tumor ... [more ▼]

Purpose or Objective Neoadjuvant radiotherapy (NeoRT) improves tumor local control and facilitates tumor resection in many cancers. We hypothesized anti-cancer treatments (i.e. radiotherapy) modify tumor microenvironment and could potentially impact distant metastases occurrence. Previously, we developed a pre-clinical model demonstrating an impact of NeoRT schedule and the timing of surgery on metastatic spreading (Leroi et al. Oncotarget 2015). Here, we aim to identify by fMRI noninvasive markers reflecting NeoRT related tumor microenvironment modifications that could predict the best timing for performing surgery and avoiding tumor spreading. Material and Methods To briefly delineate the NeoRT model, MDA-MB 231 tumor cells implanted in the flank of SCID mice were locally irradiated with 2x5Gy when tumor reached 100mm3 and then surgically removed at different time points. We performed fMRI, Diffusion Weighted (DW) and Dynamic Contract enhancement (DCE) – MRI, before RT and every 2 days between RT and surgery. We acquired 8 slices of 1 mm thickness and 0.5 mm gap with an “in plane voxel resolution” of 0.5 mm. For DW-MRI, we performed FSEMS (Fast Spin Echo MultiSlice) sequences, with 9 different Bvalue (from 40 to 1000) and B0. We performed IVIM (IntraVoxel Incoherent Motion) analysis to obtain information on intravascular diffusion, related to perfusion (F: perfusion factor) and subsequently tumor vessels perfusion. For DCE-MRI, we performed a T1 mapping with multiple TR and DCE acquisition with 200 repetitions of 3 sec each and gadolinium IV injection after 10 repetitions. We performed semi-quantitative analysis. We validated tumor perfusion by immunochemistry with injection of FITC-dextran IV 3 min before surgery and CD31 labelling. Human Ki67 was used for lung metastases labelling and quantification. Results After the tumor irradiation, we observed a significant and transient increase at day 6 (60% of the basal value (n=6, p<0,05)) of F and D* parameters related to perfusion. The other parameters of the DW-MRI, ADC and D presented no modifications. The sham irradiated tumors used as control showed no modifications of all fMRI parameters. At the same timing, 6 days post-radiotherapy, DCE-MRI significantly demonstrated a WhashinSlope (n=13, p<0,05) increase. Immunochemistry confirmed the increase of tumor perfusion when surgery is performed at day 6. The sham irradiated tumors never demonstrated such changes. Finally, when surgery is performed on tumor increased perfusion measured by fMRI, it demonstrated a burst of lung metastasis compared to the other timings. Conclusion We showed a significant difference in perfusion-related parameters with fMRI and immunochemistry at a specific time point after NeoRT. These modifications are correlated with an increase of metastasis spreading related to surgery procedure. These results open new perspectives in the personalized medicine and MRI guided surgery timing after NeoRT. [less ▲]

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See detailhMRI – A toolbox for quantitative MRI in neuroscience and clinical research
Tabelow, Karsten; Balteau, Evelyne ULiege; Ashburner, John et al

in NeuroImage (2019)

Neuroscience and clinical researchers are increasingly interested in quantitative magnetic resonance imaging (qMRI) due to its sensitivity to micro-structural properties of brain tissue such as axon ... [more ▼]

Neuroscience and clinical researchers are increasingly interested in quantitative magnetic resonance imaging (qMRI) due to its sensitivity to micro-structural properties of brain tissue such as axon, myelin, iron and water concentration. We introduce the hMRI-toolbox, an open-source, easy-to-use tool available on GitHub, for qMRI data handling and processing, presented together with a tutorial and example dataset. This toolbox allows the estimation of high-quality multi-parameter qMRI maps (longitudinal and effective transverse relaxation rates R1 and R2*, proton density PD and magnetisation transfer MT saturation) that can be used for quantitative parameter analysis and accurate delineation of subcortical brain structures. The qMRI maps generated by the toolbox are key input parameters for biophysical models designed to estimate tissue microstructure properties such as the MR g-ratio and to derive standard and novel MRI biomarkers. Thus, the current version of the toolbox is a first step towards in vivo histology using MRI (hMRI) and is being extended further in this direction. Embedded in the Statistical Parametric Mapping (SPM) framework, it benefits from the extensive range of established SPM tools for high-accuracy spatial registration and statistical inferences and can be readily combined with existing SPM toolboxes for estimating diffusion MRI parameter maps. From a user's perspective, the hMRI-toolbox is an efficient, robust and simple framework for investigating qMRI data in neuroscience and clinical research. [less ▲]

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See detailRelationship between cerebral amyloid burden and cerebral microstructure measured by quantitative MRI in healthy aging
Villar Gonzalez, Pamela ULiege; Chylinski, Daphné ULiege; Narbutas, Justinas ULiege et al

in Frontiers (2018, August 22)

The presence of Alzheimer’s disease (AD) biomarkers in the brain of healthy older individuals has been associated with decreased myelin and increased iron deposits in the brain (Bartzokis, 2011). Novel ... [more ▼]

The presence of Alzheimer’s disease (AD) biomarkers in the brain of healthy older individuals has been associated with decreased myelin and increased iron deposits in the brain (Bartzokis, 2011). Novel Magnetic Resonance Imaging (MRI) techniques, like quantitative multiparameter mapping (MPM), allow to gain insight in the microstructure of the brain and could help to address the link between myelin and iron in the brain (Callaghan et al., 2014) and AD biomarkers. Our aim was, therefore, to relate the amount of myelin and iron content to the cortical amyloid burden. We acquired MPM sequences in a 3T scanner and [18F]flutemetamol positron-emission tomography (PET) images in 55 cognitively healthy adults (35 women), aged 50-70 (mean: 59.5 ± 5.5). We used MPM to infer myelin content, based on magnetization transfer saturation (MT) and longitudinal relaxation rate (R1), and iron content, based on effective transverse relaxation rate (R2*). Cortical beta-amyloid burden was measured with [18F]flutemetamol PET. Multiparameter maps were created and normalised with the hMRI (Balteau et al., 2018) toolbox for MATLAB (The Mathworks Inc, Natick, MA, USA). Correlations between MPM maps and amyloid burden were conducted with SPM12 framework (Wellcome Trust Centre for Neuroimaging, London) p<.05 FWE corrected. As expected (Dean et al., 2017), we observed a link between increased amyloid burden and increased iron content in frontal areas mainly but also in parietal and occipital areas. However, there was an unexpected negative correlation between amyloid burden and white matter iron content in the left superior temporal area. Moreover, a positive association between amyloid burden and myelin content was found in the frontal and temporal lobes in both grey and white matter. Furthermore, R1 values, which depend on both iron and myelin storage, present positive correlations with amyloid burden in both grey and white matter of frontal, temporal and occipital areas. The finding that increased iron in frontoparietal and occipital areas are associated with increased amyloid burden fits with previous studies. However, current results also indicate that individuals with higher cortical amyloid burden have higher myelin water fraction in frontotemporal areas. This would suggest that, in cognitively healthy middle-aged individuals, the presence of amyloid in the brain, which represents a risk factor for AD, is accompanied by both cerebral microstructural decline in some areas and enhanced –possibly compensatory- microstructure properties in other areas. [less ▲]

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See detailThe hMRI analysis toolbox for quantitative MRI and in vivo histology using MRI (hMRI)
Balteau, Evelyne ULiege; Leutritz, Tobias; Lutti, Antoine et al

Poster (2018, June)

Quantitative magnetic resonance (qMRI) finds increasing interest in neuroscience and clinical research due to its greater specificity and its sensitivity to microstructural properties of brain tissue ... [more ▼]

Quantitative magnetic resonance (qMRI) finds increasing interest in neuroscience and clinical research due to its greater specificity and its sensitivity to microstructural properties of brain tissue - myelin, iron and water concentration. We introduce the hMRI toolbox, an easy-to-use open-source tool for data handling and processing of quantitative MRI data. This toolbox, embedded in the SPM framework, allows the estimation of quantitative MRI maps (longitudinal and transverse relaxation rates R1 and R2*, proton density PD, and magnetization transfer MT), followed by spatial registration in common space for statistical analysis. It also offers flexibility for calculation of novel MRI biomarkers of tissue microstructure. The hMRI toolbox can be downloaded from http://hmri.info. [less ▲]

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See detailThe “hMRI Toolbox” for quantitative imaging & in vivo histology using MRI
Phillips, Christophe ULiege; Balteau, Evelyne ULiege; Leutritz, Tobias et al

Poster (2018, June)

Quantitative magnetic resonance imaging (qMRI) finds increasing application in neuroscience and clinical research due to its greater specificity and its sensitivity to microstructural properties of brain ... [more ▼]

Quantitative magnetic resonance imaging (qMRI) finds increasing application in neuroscience and clinical research due to its greater specificity and its sensitivity to microstructural properties of brain tissue, such as myelin, iron and water concentration. We introduce the “hMRI Toolbox”, an easy-to-use open-source tool for generating and processing quantitative MRI data. This toolbox is embedded in the SPM framework, profiting from the high accuracy spatial registration in common space and the variety of available statistical analyses. It allows the estimation of quantitative MRI maps, precisely longitudinal (R1=1/T1) and effective transverse (R2*=1/T2*) relaxation rates, proton density (PD) and magnetization transfer (MT), followed by spatial registration in common space for statistical analysis. The calculation of other or novel MRI biomarkers of tissue microstructure could be added. The hMRI toolbox can be downloaded from http://hmri.info. [less ▲]

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See detailDegree of Centrality within the motor network for Parkinson’s Disease
Baquero Duarte, Katherine Andrea ULiege; Guldenmund, Pieter; Rouillard, Maud et al

Poster (2018, June)

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See detailTumor microenvironment modifications recorded with IVIM perfusion analysis after radiotherapy.
LALLEMAND, François ULiege; LEROI, Natacha ULiege; Bahri, Mohamed Ali ULiege et al

in Radiotherapy and Oncology (2018, April), 127(Supplement 1), 1285-1286

Purpose or Objective Neoadjuvant radiotherapy (NeoRT) improves tumor local control and facilitates tumor resection in many cancers. The timing between the end of the NeoRT and surgery is driven by the ... [more ▼]

Purpose or Objective Neoadjuvant radiotherapy (NeoRT) improves tumor local control and facilitates tumor resection in many cancers. The timing between the end of the NeoRT and surgery is driven by the occurrence of side effects or the tumor downsizing. Some clinical studies demonstrated that the timing of surgery and the RT schedule influence tumor dissemination and subsequently patient overall survival (Acta Oncol 2006). Previously, we developed a pre-clinical model demonstrating an impact of NeoRT schedule and the timing of surgery on metastatic spreading (Oncotarget 2015). Here, we used functional MRI (fMRI) to record tumor microenvironment modifications after NeoRT. We aim to get non-invasive markers to establish the best timing to perform surgery and avoiding tumor spreading. Material and Methods Based on our NeoRT model, MDA-MB 231 and 4T1 cells were implanted in the flank of SCID and BalbC mice, respectively. We locally irradiated (PXI, X-Rad SmART) tumors with 2x5Gy and then surgically removed at different time points after RT. We acquired fMRI (9,4T Agilent) before and after RT. Diffusion Weighted (DW) - MRI was performed every 2 days between RT and surgery. For each tumor, we acquired 8 slices of 1 mm thickness and 0.5 mm gap with an "in plane voxel resolution” of 0.5 mm. For DW-MRI, we performed FSEMS (Fast Spin Echo MultiSlice) sequences, with 9 different B-value (from 40 to 1000) and B0, in the 3 main directions. We performed IVIM (IntraVoxel Incoherent Motion) analysis to obtain information on intravascular diffusion, related to perfusion (F: perfusion factor) and subsequently tumor vessels perfusion. Results With the MDA-MB 231, we observed a significant and transient increase (60% of the basal value (n=6, p<0,05)) of F and D* parameters related to perfusion. The other parameters of the DW-MRI, ADC and D presented no modification. We observed similar results with 4T1 cells, where F increased at day 3 (55% of the basal value, n=10, p<0,05) then returned to initial level. The difference in timing for the peak of F (day 6 vs day 3) could be related to the difference in tumor growth according to the cell line (four weeks for MDA-MB 231 cells vs one week for 4T1 cells). We also observed a decrease of hypoxia (pimonidazole staining) when surgery was performed on the peak but vascular architecture was not affected. Moreover, performing surgery during F and D* peak, in the MDA-MB 231model, is associated with an increase of lung metastases: 115% and 187% compared to a surgery performed before or after the peak. Conclusion We demonstrated the feasibility of repetitive fMRI imaging in preclinical models after NeoRT. We showed a significant difference in perfusion-related parameters (D* and F) at a specific time point depending of tumor cells correlated with tumor metastases. We demonstrated the feasibility of Image Guided Surgery for decreasing tumor metastases after NeoRT. [less ▲]

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See detailBrain modifications after stereotactic radiotherapy recorded by Functional MRI.
LALLEMAND, François ULiege; LEROI, Natacha ULiege; Bahri, Mohamed Ali ULiege et al

in Radiotherapy and Oncology (2018, April), 127(Supplement 1), 582

Purpose or Objective Brain irradiation is commonly used in malignant diseases (i.e. metastases or Glioblastoma) and in benign diseases (i.e. meningioma, epilepsy, vestibular schwannoma or Parkinson ... [more ▼]

Purpose or Objective Brain irradiation is commonly used in malignant diseases (i.e. metastases or Glioblastoma) and in benign diseases (i.e. meningioma, epilepsy, vestibular schwannoma or Parkinson disease). The use of stereotactic radiosurgery (SRS) allows the administration of very high doses in a single fraction (e.g. 120Gy), in a small brain volume. After irradiation, morphological and functional cerebral changes occur depending on the total dose, dose per fraction and the irradiated brain volume. The aim of this work is to use f-MRI to record adult normal brain tissue modification after irradiation with different radiotherapy doses and schedules and to identify new parameters of brain radio-damages. Material and Methods With a dedicated small animal radiotherapy device allowing IGRT (PXI, X-Rad SmART), we specifically irradiated with a 2mm-collimator, mimicking SRS, a small part of adult brain mice (n=72), known to have no impact on vital function, with dose schedules: 1X20Gy, 3X10Gy, 4X5Gy and no RT as control. We imaged brain mice longitudinally with a dedicated 9.4-T MRI (Agilent). Imaging was realized once before as reference level and after irradiation every month for the first 6 months and every 3 months during one year. For each mouse we acquired 14 slices of 1 mm thickness and 0.5 mm gap with an “in plane voxel resolution” of 0.5 mm. We performed T1-weighted, T2-weighted, T1-mapping, T2-mapping and DW-MRI. For DW-MRI, we performed Fast Spin Echo MultiSlice sequences, with 9 different B-value and B0 (from 20 to 1000). We performed IntraVoxel Incoherent Motion (IVIM) analysis to obtain information on intravascular diffusion, related to perfusion (F: perfusion factor). Results Only mice irradiated with 120Gy showed brain modifications in T1 and T2 anatomic images and in T1 mapping, ADC, D and F but no changes were recorded in D* or T2 mapping. All these changes started 5 weeks after SRS and then stabilized after 7 weeks. The mean values for the control group were stable during the 5 months (ADC 0,73μm²/ms; D 0,66μm²/ms; F 4,67%, T1 1,25 sec). For the 120Gy group, values were significantly higher after 5 weeks (Δ = compared to the control group) with ADC 1,66μm²/ms (Δ=151%); D 1,37μm²/ms (Δ=107%); F 18,84% (Δ=303%); T1 1,99 sec (Δ=59%). No specific behaviour changes were observed during all the experiment. Conclusion In this work, we studied normal brain modifications after SRS therapy with anatomical and functional MRI. SRS doses and schedules in this work reflected those used in clinic for tumor treatment or functional SRS. We showed an increase of ADC value 5 weeks after one single dose of 120Gy, compared to normal brain tissue. These results are consistent with radio-necrosis. In addition, we highlighted an increase of IVIM parameters D and F and an increase of T1 mapping in radio-necrosis area. These results increase the numbers of MRI parameters that could be used for following brain damage after radiation. [less ▲]

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See detailhMRI - A toolbox for using quantitative MRI in neuroscience and clinical research
Balteau, Evelyne ULiege; Tabelow, Karsten; Ashburner, John et al

Software (2018)

Quantitative magnetic resonance imaging (qMRI) finds increasing application in neuroscience and clinical research due to its sensitivity to micro-structural properties of brain tissue, e.g. axon, myelin ... [more ▼]

Quantitative magnetic resonance imaging (qMRI) finds increasing application in neuroscience and clinical research due to its sensitivity to micro-structural properties of brain tissue, e.g. axon, myelin, iron and water concentration. We introduce the hMRI--toolbox, an easy-to-use open-source tool for handling and processing of qMRI data presented together with an example dataset. This toolbox allows the estimation of high-quality multi-parameter qMRI maps (longitudinal and effective transverse relaxation rates R1 and R2*, proton density PD and magnetisation transfer MT) that can be used for calculation of standard and novel MRI biomarkers of tissue microstructure as well as improved delineation of subcortical brain structures. Embedded in the Statistical Parametric Mapping (SPM) framework, it can be readily combined with existing SPM tools for estimating diffusion MRI parameter maps and benefits from the extensive range of available tools for high-accuracy spatial registration and statistical inference. As such the hMRI--toolbox provides an efficient, robust and simple framework for using qMRI data in neuroscience and clinical research. [less ▲]

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See detailThe hMRI toolbox for quantitative imaging and in vivo histology using MRI (hMRI)
Phillips, Christophe ULiege; Balteau, Evelyne ULiege; Leutritz, Tobias et al

Conference (2018)

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See detailIntellectual and social enrichement linked to larger hippocampal volume in healthy aging
Narbutas, Justinas ULiege; Van Egroo, Maxime ULiege; Besson, Gabriel ULiege et al

Poster (2017, November 24)

Introduction. Decreased hippocampal volume in older adults is associated with episodic memory decline and subsequent neurodegenerative diseases. According to the dynamic polygon hypothesis, strategies ... [more ▼]

Introduction. Decreased hippocampal volume in older adults is associated with episodic memory decline and subsequent neurodegenerative diseases. According to the dynamic polygon hypothesis, strategies that increase neurogenesis of the hippocampus are likely to be successsful in delaying the onset of cognitive impairment in ageing. Several modifiable factors can have a positive effect on the size of the hippocampus, one of them being cognitive reserve. However, to date, very few studies reported an impact of cognitive reserve on hippocampal volume in healthy older adults. Therefore, the main objective of our study was to explore whether cognitive reserve is linked to hippocampal volume in healthy aging. We focussed particularly on intellectual and social enrichment during lifespan, because these aspects have been linked to hippocampal volume in clinical populations. Methods. Twenty-six healthy late middle-aged participants (51-69 y.o.) underwent 3T magnetic resonance imaging. Hippocampal volume was calculated with the Automatic Segmentation of Hippocampal Subfields (ASHS) software, which uses T1-weighted and T2-weighted MRI to obtain optimal segmentation of the hippocampus and its subfields. Raw volumetric scores obtained with ASHS were controlled for age and total intracranial brain volume. Only the main hippocampal regions (CA1, CA2, CA3, dentate gyrus) were included in the analysis. Volunteers also completed a questionnaire quantifying their lifespan engagement in intellectual (i.e. reading, hobbies) and social (i.e., volunteering, social games) enrichment. More specifically, participants had to describe the frequency of each activity they have engaged in from 6 years old to the present day. Results. Pearson correlation and hierarchical linear regression analyses revealed that higher frequency of intellectual (r = 0.40; p = 0.023) and social (r = 0.44; p = 0.013) enrichment was significantly linked to larger hippocampal volume, even when controlling for age and sex. Education, another proxy of cognitive reserve, had, however, no significant association with hippocampal volume, possibly due to restricted variance in education and small sample size. Conclusion. These results suggest that in a late middle-aged population, lifespan intellectual and social enrichment is related to larger hippocampal volume. These findings could indicate that lifespan enrichment promotes hippocampal neurogenesis. Future analysis on a larger sample will distinguish the impact of early and later life enrichment on hippocampal volume and will also assess whether this relation can modulate hippocampal-related changes in episodic memory in aging population. [less ▲]

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See detailMean and variance of Dynamic Functional Connectivity in Parkinson’s Disease
Baquero Duarte, Katherine Andrea ULiege; Guldenmund, Pieter; Rouillard, Maud ULiege et al

Poster (2017, June 29)

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See detailFollowing tumour microenvironment after Neoadjuvant radiotherapy with IVIM perfusion analysis.
LALLEMAND, François ULiege; LEROI, Natacha ULiege; Bahri, Mohamed Ali ULiege et al

in Radiotherapy and Oncology (2017, May), 123(Supplement 1), 545

Purpose or Objective Neoadjuvant radiotherapy (NeoRT) improves tumor local control and facilitates tumor resection in many cancers. The timing between the end of the NeoRT and surgery is driven by the ... [more ▼]

Purpose or Objective Neoadjuvant radiotherapy (NeoRT) improves tumor local control and facilitates tumor resection in many cancers. The timing between the end of the NeoRT and surgery is driven by the occurrence of side effects or the tumor downsizing. Some clinical studies demonstrated that the timing of surgery and the RT schedule influence tumor dissemination and subsequently patient overall survival. Previously, we developed a pre-clinical model demonstrating an impact of NeoRT schedule and the timing of surgery on metastatic spreading (Leroi et al. Oncotarget 2015). Here, we evaluate the impact of NeoRT on the tumor microenvironment by functional MRI (fMRI). We aim to identify non-invasive markers allowing to determine the best timing to perform surgery and avoiding tumor spreading. Material and Methods Based on our NeoRT model, MDA-MB 231 and 4T1 cells were implanted in the flank of SCID and BalbC mice, respectively. We locally irradiated tumors with 2x5Gy and then surgically removed at different time points after RT. Diffusion Weighted (DW) -MRI was performed every 2 days between RT and surgery. For each tumors we acquired 8 slices of 1 mm thickness and 0.5 mm gap with an 'in plane voxel resolution” of 0.5 mm. For DW-MRI, we performed FSEMS (Fast Spin Echo MultiSlice) sequences, with 9 different B-value (from 40 to 1000) and B0, in the 3 main directions. We performed IVIM (IntraVoxel Incoherent Motion) analysis to obtain information on intravascular diffusion, related to perfusion (F: perfusion factor) and subsequently tumor vessels perfusion. Results With the MDA-MB 231, we observed a significant peak of F at day 6 after irradiation, this increasing is about 60% of the basal value (n=6, p<0,05). Moreover, D* parameters (also related to perfusion) increase at the same time. The other parameters of the DW-MRI, ADC and D presented no modification. We observed similar results with 4T1 cells, where F increased at day 3 (about 55%, n=10, p<0,05) then returned to initial level. The difference in timing for the peak of F (day 6 vs day 3) could be related to the difference in tumor growth according to the cell line (four weeks for MDA-MB 231 cells vs one week for 4T1cells). We performed surgery at the time of the F parameter peak in the MDA-MB 231 and we observed a decrease of the metastasic burden compared to surgery performed at day 4 or day 11(absolute number of metastasis 23 VS 1 VS 8 with n=4). Conclusion For the first time, we demonstrate the feasibility of repetitive fMRI imaging in preclinical models after NeoRT. With these models, we show a significant difference in perfusion-related parameters (D* and F) at a specific time point depending of the tumor cells. These modifications are correlated to a decrease of metastasis spreading related to the surgery procedure. These results open new perspectives in the personalized medicine and MRI guided surgery timing after NeoRT. [less ▲]

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See detailCerebral Activity Associated with Transient Sleep-Facilitated Reduction in Motor Memory Vulnerability to Interference
Albouy, Geneviève; King, Bradley; Schmidt, Christina ULiege et al

in Scientific Reports (2016), 6

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See detailLocal modulation of human brain responses by circadian rhythmicity and sleep debt
Muto, Vincenzo ULiege; Jaspar, Mathieu ULiege; Meyer, Christelle et al

in Science (2016), 351(6300),

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