First experimental proof of Proton Boron Capture Therapy (PBCT) to enhance protontherapy effectiveness

Authors:   G. Cirrone,L. Manti,D. Margarone,G. Petringa,L. Giuffrida,A. Minopoli,A. Picciotto,G. Russo,F. Cammarata,P. Pisciotta,F. Perozziello,F. Romano,V. Marchese,G. Milluzzo,V. Scuderi,G. Cuttone,G. Korn
Journal: Scientific Reports
https://doi.org/10.1038/s41598-018-19258-5
Abstract: Protontherapy is hadrontherapy’s fastest-growing modality and a pillar in the battle against cancer. Hadrontherapy’s superiority lies in its inverted depth-dose profile, hence tumour-confined irradiation. Protons, however, lack distinct radiobiological advantages over photons or electrons. Higher LET (Linear Energy Transfer) 12C-ions can overcome cancer radioresistance: DNA lesion complexity increases with LET, resulting in efficient cell killing, i.e. higher Relative Biological Effectiveness (RBE). However, economic and radiobiological issues hamper 12C-ion clinical amenability. Thus, enhancing proton RBE is desirable. To this end, we exploited the p + 11B → 3$alpha$ reaction to generate high-LET alpha particles with a clinical proton beam. To maximize the reaction rate, we used sodium borocaptate (BSH) with natural boron content. Boron-Neutron Capture Therapy (BNCT) uses 10B-enriched BSH for neutron irradiation-triggered alpha particles. We recorded significantly increased cellular lethality and chromosome aberration complexity. A strategy combining protontherapy’s ballistic precision with the higher RBE promised by BNCT and 12C-ion therapy is thus demonstrated.