Microdosimetric analysis of proton boron capture therapy using microdosimetric kinetic model

Rahim, A.*; 佐藤 達彦   ; 福田 寛*; Beni, M. S.*; 渡部 浩司*

Rahim, A.*; Sato, Tatsuhiko; Fukuda, Hiroshi*; Beni, M. S.*; Watabe, Hiroshi*

Proton boron fusion therapy (PBFT) aims to enhance proton therapy through particles generated by the reaction. While early reports suggested large dose gains near the Bragg peak, later studies questioned its feasibility due to the low cross section and the need for unrealistically high boron concentrations. In this study, Monte Carlo microdosimetric analysis showed that protons dominate total dose delivery, with particles contributing only locally to high-LET deposition. The resulting RBE enhancement factors were negligible at 100-1000 ppm boron and modest () only at 10,000 ppm. These findings indicate that, under clinically realistic conditions, the therapeutic benefit of PBFT is minimal.