"MAPPING BORON LOCATION IN CELLS USING SOFT X-RAY EMISSION SPECTROSCOPY".

THIS PROJECT WILL RESULT IN THE DEVELOPMENT OF A NEW TECHNOLOGY FOR MEASURING THE QUANTITY AND LOCATION, WITH SUBMICRON RESOLUTION, OF BORON IN BIOLOGICAL CELLS IN SUPPORT OF THE BORON NEUTRON CAPTURE THERAPY (BNCT) PROGRAM. THIS PROJECT THUS ADDRESSES THE MAJOR UNSOLVED TECHNICAL ISSUE IMPACTING BNCT CLINICAL EFFICACY. BNCT IS APROMISING RADIATION THERAPY IN WHICH NEUTRONS ARE USED TO ACTIVATE BORON THAT HAS BEEN PRE-POSITIONED WITHIN THE CELL BY BIOCHEMICAL TECHNIQUES. WHEN A BORON ATOM CAPTURES A THERMAL NEUTRON, THE SUBSEQUENT REACTION PRODUCES AN ENERGETIC ALPHA PARTICLE AND LI ION WITH RANGES APPROXIMATELY ONE CELL DIAMETER. THE SHORT RANGES OF THE REACTION PRODUCTS LIMIT DAMAGE TO SURROUNDING TISSUE, BUT REQUIRES THAT THE BORON BE PROPERLY POSITIONED, IN THERAPEUTIC QUANTITIES, WITHIN THE CELL WALL. ADEQUATE MEANS OF DETECTING INTRACELLULAR BORON DO NOT CURRENTLY EXIST. IN THIS PROJECT WE PROPOSE TO DESIGN AND CONSTRUCT A NEW, HIGHLY EFFICIENT TRANSMISSION GRATING SPECTROMETER (TGS) THAT CAN BE ATTACHED TO A SCANNING ELECTRON MICROSCOPE(SEM) AND USED TO DETECT THE BORON-K SOFT X-RAY RADIATION EXCITED BY THE SEM BEAM. THIS SEM-TGS SYSTEM CAN BE USED TOMAP THE BORON CONTENT, LOCATION AND VARIABILITY WITHIN BIOLOGICAL CELLS WITH SUBMICRON RESOLUTION.