Technical advances in x-ray microbeam radiation therapy.

摘要: In the last 25 years microbeam radiation therapy (MRT) has emerged as a promising alternative to conventional at large, third generation synchrotrons. MRT, multi-slit collimator modulates kilovoltage x-ray beam on micrometer scale, creating peak dose areas with unconventionally high doses of several hundred Grays separated by low valley regions, where remains well below tissue tolerance level. Pre-clinical evidence demonstrates that such geometries lead substantially reduced damage normal equal tumour control rates and hence drastically increase therapeutic window. Although mechanisms behind MRT are still be elucidated, previous studies indicate immune response, microenvironment, microvasculature may play crucial role. Beyond therapy, also been suggested microsurgical tool in neurological disorders primer for drug delivery. The physical properties demand innovative medical physics engineering solutions safe treatment This article reviews technical developments discusses existing dosimetric validation, reliable planning safety. Instrumentation synchrotron facilities, including production, collimators patient positioning systems, is discussed. Specific reviewed this include: dosimetry techniques can cope spatial resolution, photon energies extremely up 15 000 Gy s-1, calculation algorithms-apart from pure Monte Carlo Simulations-to overcome challenge small voxel sizes wide dynamic dose-range, use dose-enhancing nanoparticles combat limited penetrability energy spectrum. Finally, concepts compact sources presented, inverse Compton scattering set-ups carbon nanotube tubes, facilitate transfer into hospital-based clinical environment. Intensive research recent resulted practical most challenges MRT. Treatment planning, safety systems synchrotrons have matured point first veterinary within reach. Should these confirm results pre-clinical studies, authors confident will become an effective new radiotherapy option certain patients.