Synchrotron radiation therapy and surgery: new methods and new results.

Synchrotron radiation facilities are laboratories where the most intense and collimated X-ray beams on Earth are made available to researchers for a wide range of scientific and biomedical applications. In medicine, synchrotron X-rays are used to develop new imaging, radiation therapy and surgery techniques, applied to in-vitro and in-vivo models. The European Synchrotron Radiation Facility (Grenoble, France) is a leading place for biomedical research with synchrotron X-rays. The platforms for stereotactic radiation therapy trials targeting brain tumours and the station for preclinical investigations in brain cancer therapy and radiation surgery using microbeams are available for the international users' community. Beams can be delivered stereotactically to a tumour previously loaded with a high Z material that allows one to locally enhance the dose deposition. In microbeam radiation therapy, multienergy X-rays are spatially fractionated in arrays of microscopic beams (from 25 to 600 microns) and delivered with submillimetric precision to the central nervous system (CNS). Doses up to hundreds of Grays, delivered in a fraction of a second, can be very well tolerated by the CNS as shown in several small and large animal models. The basic concepts and highlights on the on-going developments will be here introduced.