Vers une nouvelle technique d’imagerie médicale dynamique par interférométrie

Un nouvel article de l'équipe IBIV a fait l'objet d'une brève sur le site de l'IN2P3. L’imagerie du contraste speckle dynamique est une technique interférométrique, qui permet la mesure in vivo en champ large des variations relatives du débit sanguin cérébral. Elle consiste à illuminer les tissus par une source cohérente, dans notre cas une diode laser rouge. Les photons rétrodiffusés par les tissus forment une figure d’interférences appelée « speckle », qui est variable au cours du temps dans le cas d’objets biologiques contenant des diffuseurs mobiles.

Soutenances de thèse

Trois thèses seront soutenues en décembre par les doctorants du laboratoire. Les soutenances auront lieu dans la salle de conférences de la Bibliothèque Universitaire (Domaine universitaire de Paris-Sud, Bât 407).
  • Mardi 18 décembre 2018 à 11h00 : Louis Ammour, "Développement d'une sonde intracérébrale à pixels actifs pour l'imagerie bêta du cerveau du rat libre de ses mouvements".
  • Mercredi 19 décembre à 14h30 : Haleh Soleimanzad, "Développement et application de l'imagerie quantitative du débit sanguin cérébral pour l'étude de modèles de l'obésité".
  • Vendredi 21 décembre à 13H30 : Alexandre Bricou, "Application d’un radio-imageur (TReCam) dans les cancers invasifs infra-cliniques du sein".

Soigner des cancers avec des minifaisceaux de protons

Une récente étude menée par l’IMNC, publiée dans la revue Nature Scientific Reports, montre des résultats encourageants sur le traitement de tumeurs radiorésistantes par minifaisceaux de protons (pMBRT). Pour la première fois, les scientifiques ont traité des cerveaux de rats atteints de gliomes de haut grade1 par pMBRT. Avec un traitement classique, la moyenne de survie des animaux est de 15 mois après diagnostic et un taux de survie de 5% au-delà de 5 ans. Avec un traitement par pMBRT, un fort contrôle de la croissance tumorale a été observé, engendrant une disparition de la tumeur dans 22% des cas, et ceci sans aucune lésion significative des tissus sains.


Publications récentes

Modeling the dynamics of oligodendrocyte precursor cells and the genesis of gliomas

Dufour A, Gontran E, Deroulers C, Varlet P, Pallud J, Grammaticos B, Badoual M.

Gliomas are the most common brain tumors and result in more years of life lost than any other tumor. Standard treatments only confer a limited improvement in overall survival, underscoring the need for new therapies. Finding the type of cells at the origin of these tumors could lead to the development of new drugs, specifically targeted towards these cells. The oligodendrocyte precursor cells are suspected to be these cells of origin, because they continue to proliferate through all the adult life.

Gamma-background rejection method for a dual scintillator positron probe dedicated to radio-guided surgery

M.-A. Verdier, S. Spadola, L. Pinot, C. Esnault, Y. Charon, M.-A. Duval, L. Ménard

We developed a positron intraoperative probe with high sensitivity dedicated to real-time assessment of the resection margins of tumors and control of the surgical cavity. Its main limitation comes from the annihilation photon background generated by distal non-specific radiotracer uptakes. This study is a proof of concept for a dual-scintillator intraoperative probe with background subtraction capability. It associates a highly p-terphenyl ββ-sensitive scintillator and a highly γγ-sensitive LYSO:Ce.

Transfer of Minibeam Radiation Therapy into a cost-effective equipment for radiobiological studies: a proof of concept

Y. Prezado, M. Dos Santos, W. Gonzalez, G. Jouvion, C. Guardiola, S. Heinrich, D. Labiod, M. Juchaux, L. Jourdain, C. Sebrie and F. Pouzoulet

Minibeam radiation therapy (MBRT) is an innovative synchrotron radiotherapy technique able to shift the normal tissue complication probability curves to significantly higher doses. However, its exploration was hindered due to the limited and expensive beamtime at synchrotrons. The aim of this work was to develop a cost-effective equipment to perform systematic radiobiological studies in view of MBRT. Tumor control for various tumor entities will be addressable as well as studies to unravel the distinct biological mechanisms involved in

Proton minibeam radiation therapy spares normal rat brain: Long-Term Clinical, Radiological and Histopathological Analysis

Y. Prezado, G. Jouvion, D. Hardy, A. Patriarca, C. Nauraye, J. Bergs, W. González, C. Guardiola, M. Juchaux, D. Labiod, R. Dendale, L. Jourdain, C. Sebrie and F. Pouzoulet

Proton minibeam radiation therapy (pMBRT) is a novel strategy for minimizing normal tissue damage resulting from radiotherapy treatments. This strategy partners the inherent advantages of protons for radiotherapy with the gain in normal tissue preservation observed upon irradiation with narrow, spatially fractionated beams. In this study, whole brains (excluding the olfactory bulb) of Fischer 344 rats (n = 16) were irradiated at the Orsay Proton Therapy Center. Half of the animals received standard proton irradiation, while the other half were

Optical properties, spectral, and lifetime measurements of central nervous system tumors in humans

F. Poulon, H. Mehidine, M. Juchaux, P. Varlet, B. Devaux, J. Pallud and D. Abi Haidar

A key challenge of central nervous system tumor surgery is to discriminate between brain regions infiltrated by tumor cells and surrounding healthy tissue. Although monitoring of autofluorescence could potentially be an efficient way to provide reliable information for these regions, we found little information on this subject, and thus we conducted studies of brain tissue optical properties. This particular study focuses on the different optical quantitative responses of human central nervous system tumors and their corresponding controls.

Experimental assessment of the safety and potential efficacy of high irradiance photostimulation of brain tissues

S. Senova, I. Scisniak, C.-C Chiang, I. Doignon, S. Palfi, A. Chaillet, C. Martin and F. Pain

Optogenetics is widely used in fundamental neuroscience. Its potential clinical translation for brain neuromodulation requires a careful assessment of the safety and efficacy of repeated, sustained optical stimulation of large volumes of brain tissues. This study was performed in rats and not in non-human primates for ethical reasons. We studied the spatial distribution of light, potential damage, and non-physiological effects in vivo, in anesthetized rat brains, on large brain volumes, following repeated high irradiance

Endogenous fluorescence analysis: preliminary study revealing the potential of this non-invasive method to study mummified samples

M. Zanello, J. Pallud, S. Jacqueline, A. Augias, P. Varlet, B. Devaux, O. Nielsen, D. Abi Haidar and P. Charlier

Autofluorescence analysis allows new insights on human tissue without any dye in a non-invasive way and therefore seems well suited to study historical samples. An optical set-up recorded emitted autofluorescence in 1/spectral and 2/lifetime domains from different samples’ regions of interest. The studied samples were: a mummified right hand; bog body (Tollund Man) feet, and a Caucasian male hand (control sample). Spectral analysis revealed that mummified hand exhibited broad autofluorescence spectra whereas Tollund Man feet exhibited a weak single peak with

Simulation of nanoparticle-mediated near-infrared thermal therapy using GATE

Vesna Cuplov, Frédéric Pain and Sébastien Jan

Application of nanotechnology for biomedicine in cancer therapy allows for direct delivery of anticancer agents to tumors. An example of such therapies is the nanoparticle-mediated near-infrared hyperthermia treatment. In order to investigate the influence of nanoparticle properties on the spatial distribution of heat in the tumor and healthy tissues, accurate simulations are required. The Geant4 Application for Emission Tomography (GATE) open-source simulation platform, based on the Geant4 toolkit, is widely used by the research community involved in

Multimodal optical analysis discriminates freshly extracted human sample of gliomas, metastases and meningiomas from their appropriate controls

M. Zanello, F. Poulon, J. Pallud, P. Varlet, H. Hamzeh, G. Abi Lahoud. F. Andreiuolo, A. Ibrahim, M. Pages, F. Chretien, F. Di Rocco, E. Dezamis, F. Nataf, B. Turak, B. Devaux and Darine Abi Haidar

Delineating tumor margins as accurately as possible is of primordial importance in surgical oncology: extent of resection is associated with survival but respect of healthy surrounding tissue is necessary for preserved quality of life. The real-time analysis of the endogeneous fluorescence signal of brain tissues is a promising tool for defining margins of brain tumors. The present study aims to demonstrate the feasibility of multimodal optical analysis to discriminate fresh samples of gliomas, metastases and meningiomas from their appropriate controls.

Design optimization and performances of an intraoperative positron imaging probe for radioguided cancer surgery

S. Spadola, M.-A. Verdier, L. Pinot, C. Esnault, N. Dinu, Y. Charon, M.-A. Duval and L. Ménard

Extent and accuracy of surgical resection is a crucial step in operable tumor therapy. Emergence of promising specific tumor-seeking agents labeled with positron emitters is giving rise to a renewed interest for radioguided surgery using beta probes. Beta detection, due to the particle short range, allows a more sensitive and accurate tumor localization compared to gamma radiotracers.


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