Miniature tissue-equivalent proportional counters for BNCT and BNCEFNT dosimetry

A dual miniature tissue-equivalent proportional counter (TEPC) system has b een developed to facilitate microdosimetry for Boron Neutron Capture Therap y (BNCT). This system has been designed specifically to allow the analysis of the single event charged particle spectrum in phantom in high intensity BNCT bean-is and to provide this microdosimetric information with excellent spatial resolution. Paired A-150 and B-10-loaded A-150 TEPCs with 12.3 mm( 3) collecting volumes have been constructed. These TEPCs allow more accurat e neutron dosimetry than current techniques, offer a direct measure of the boron neutron capture dose, and provide a framework for predicting the biol ogical effectiveness of the absorbed dose. Design aspects and characterizat ion of these detectors are reviewed, along with an exposition of the advant ages of microdosimetry using these detectors over conventional dosimetry me thods. In addition, the utility of this technique for boron neutron capture enhancement of fast neutron therapy (BNCEFNT) is discussed. (C) 2001 Ameri can Association of Physicists in Medicine.