Synchrotron-generated microbeam radiosurgery: a novel experimental approach to modulate brain function.

Synchrotron-generated X-ray microplanar beams (microbeams) are characterized by peculiar biological properties such as a remarkable tissue-sparing effect in healthy tissues including the central nervous system (CNS) and, as a direct consequence, the ability to deliver extremely high doses without induction of radionecrosis. Growing experimental evidence is showing remarkable tolerance of brain and spinal cord to irradiation with microbeam arrays delivering doses up to 400 Gy with a beam width up to 0·7 mm. Submillimetric beams can be delivered following a stereotactic design bringing to the target doses in the range of hundreds of Gray without harm to the surrounding tissues. Microbeam arrays can be used to generate cortical transections or subcortical lesions, thus enabling the non-invasive modulation of brain networks. This novel microradiosurgical approach is of great interest for the treatment of a variety of brain disorders, including functional diseases such as epilepsy and movement disorders.