Abstract #1011

MRI Characterization of a Focal Rat Brain Necrosis Induced by Interlaced Microbeam Radiation Therapy.

Raphael Serduc^1,2, Nicolas Pannetier³, Audrey Bouchet², Thierry Brochard², Thomas Christen³, Gilles Berruyer⁴, Jean Laissue⁵, Francois Esteve³, Chantal Remy³, Emmanuel Barbier³, Alberto Bravin², Graldine Le Duc², Elke Brauer²

¹CERCO, CNRS, Toulouse, France; ²Imaging Group, ESRF, Grenoble, France; ³U836, INSERM, Grenoble, France; ⁴Scisoft Group, ESRF, Grenoble, France; ⁵Bern Institute of pathology, Bern, Switzerland

We developed here a new irradiation modality which produced a very high (200Gy) uniform radiation dose to a restricted target in the rat brain using interlaced synchrotron microbeam radiation therapy. A local extravasation of Gd-DOTA (starting at day 7) and significant increases in T2W and ADC after exposure were observed by MRI at D30. Three months after irradiation, the lesion still exhibited higher ADC values. These changes characterized a focal necrosis confined to the radiation target while normal tissues surrounding the lesion were spared. This new irradiation method could be useful for any brain lesions involving radiosurgery.