BNCT Microdosimetry of a Rat Glioma Model with BPA-F or BSH

Abstract

The BNCT microdosimetry technique developed in the Harvard-MIT BNCT Program involves both experimental and computational components. First, a neutron-induced alpha particle track etch technique developed in our laboratory termed High Resolution Quantitative Autoradiography (HRQAR) is used to measure the microscopic distribution of 10B in a thin tissue section.1 HRQAR allows simultaneous visualization of tissue histology and track etch pits, which sample the 10B microdistribution. The polycarbonate track detector used in the technique is sensitive only to high LET particles (not protons) and has a linear response and sensitivity down to ~1 μg/g10B. By employing the actual boron microdistribution and tissue morphology obtained with the HRQAR technique in a 2D Monte Carlo simulation of charged particle transport and energy deposition in tissue, our approach to BNCT microdosimetry circumvents the simplifying assumptions usually required in microdosimetry, i.e., using elementary mathematical shapes and functions to represent the tissue architecture and boron distribution. This paper will discuss microdosimetric results obtained for 9L gliosarcoma in rats injected with boronophenylalanine-fructose (BPA-F) or Na2B12H11SH (BSH) using the HRQAR-based microdosimetry technique.