Neutron capture autoradiographic determination of B-10 distributions and concentrations in biological samples for boron neutron capture therapy

It is necessary for effective boron neutron capture therapy (BNCT) to accum ulate B-10 atoms in the tumor cells. We prepared a cationic liposome entrap ped B-10 compound for the delivery system and examined the delivery capacit y of B-10 atoms to pancreatic cancer cell, AsPC-1, in vivo. It is required to achieve an accurate measurement of B-10 distributions and concentrations in biological samples with a sensitivity in the ppm range for BNCT, We app lied CR-39 (polyallyldiglycol carbonate) plastic track detectors to alpha-a utoradiographic measurements of the B-10 biodistribution in sliced whole-bo dy samples of mice. To selectively desensitize undesirable proton tracks, w e applied PEW (KOH + C2H5OH + H2O) solution to the etching of CR-39 detecto r. The subsequent use of an alpha-track radiographic image analysis system enabled a discrimination between alpha tracks and recoiled proton tracks by the track size selection method. This enabled us to estimate quantitativel y the distributions of B-10 concentrations within the tissue sections by co mparing with suitable standards. (C) 1999 Elsevier Science B.V. All rights reserved.