Prompt gamma ray diagnostics and enhanced hadron-therapy using neutron-free nuclear reactions

Abstract

We propose a series of simulations about the potential use of Boron isotopes to trigger neutron-free (aneutronic) nuclear reactions in cancer cells through the interaction with an incoming energetic proton beam, thus resulting in the emission of characteristic prompt gamma radiation (429 keV, 718 keV and 1435 keV). Furthermore assuming that the Boron isotopes are absorbed in cancer cells, the three alpha-particles produced in each p-11 B aneutronic nuclear fusion reactions can potentially result in the enhancement of the biological dose absorbed in the tumor region since these multi-MeV alpha-particles are stopped inside the single cancer cell, thus allowing to spare the surrounding tissues. Although a similar approach based on the use of 11 B nuclei has been proposed in [1], our work demonstrate, using Monte Carlo simulations, the crucial importance of the use of 10 B nuclei (in a solution containing also 11 B) for the generation of prompt gamma-rays, which can be applied to medical imaging. In fact, we demonstrate that the use of 10 B nuclei can enhance the intensity of the 718 keV gamma-ray peak more than 30 times compared to the solution containing only 11 B nuclei. A detailed explanation of the origin of the different prompt gamma-rays, as well as of their application as real-time diagnostics during a potential cancer treatment, is here discussed.

High-current stream of energetic α particles from laser-driven proton-boron fusion

“…Recently, much interest has focused on using the α particles generated by such reaction for cancer treatments in human bodies. According to Yoon et al [15] and Giuffrida et al [16], based on Monte Carlo simulations, cancer treatment using the pB reaction could produce an enhancement of the treatment biological effectiveness, if compared with standard proton therapy. Experimental campaigns conducted in-vivo on boron-treated cancer cells by Cirrone et al [17] demonstrated the potential clinical efficacy of this approach.…”

“…Moreover, Petringa et al [18,19] proposed that prompt γ 's emitted in the pB reactions could be used for on-line proton beam imaging purposes during cancer treatment, also reported in Refs. [15,16].…”

“…The nuclear reaction known as proton-boron fusion has been triggered by a subnanosecond laser system focused onto a thick boron nitride target at modest laser intensity (∼10 16 W/cm 2 ), resulting in a record yield of generated α particles. The estimated value of α particles emitted per laser pulse is around 10 11 , thus orders of magnitude higher than any other experimental result previously reported.…”

New approaches in clinical application of laser-driven ionizing radiation

“…They demonstrated by MCNP6 simulations that the proton-boron fusion reaction rate at clinically relevant boron concentrations (100 ppm) is too small in order to have any measurable impact on the absorbed dose. Other groups stated as well, that the magnitude of dose increase using realistic boron concentration values remains under 10 % and the dose increase occurs mainly due to the composition and the density changes instead of alpha particle contribution [23][24][25]. The additional physical dose from BPF reaction calculated around 0,3 %.…”

11Boron Delivery Agents for Boron Proton-capture Enhanced Proton Therapy

“…The highest probability for the most effective combination of BPC and proton dose occurs at a discrete proton energy level of 675 keV (5)(6)(7)(8)(9). Accessing this energy requires an initial proton deceleration to a certain position along the proton dose-depth curve (under the Bragg peak or at the end of the spread of the Bragg peak) and thus the BPC reaction can be defined with submillimeter accuracy.…”