Speaker
Description
Proton radiation therapy exploits the localized energy deposition of proton beams at the Bragg peak. Its main advantage is the ability to deliver a high dose to the tumor while minimizing exposure to surrounding healthy tissues. However some limitations exist; for example, tumors located near critical organs may not receive a sufficiently high therapeutic dose without risking damage to healthy tissues. For this reason, two new techniques have been recently proposed, in which the dose in the Bragg peak should be enhanced by the high LET alpha-particles produced in proton- or neutron-induced reactions on boron.
In Proton Boron Capture Therapy (PBCT), an enhancement in the dose to tumor is expected from the p+11B->3alpha reaction. Evidences of a lower survival probability of boron-loaded tumor cells irradiated with low-energy protons have been reported [1]. However, both calculations [2] and measurements [3] have cast some doubts on the effectiveness of this methodology. In Neutron Capture Enhanced Proton Therapy (NCEPT), an increased dose to tumor is expected to occur as a consequence of the 10B(n,alpha) reaction, induced by secondary neutrons produced by proton interaction in the biological tissues [4]. In this case as well, however, experimental results [3] and new calculations [5] do not show evidence of an effective therapeutic gain.
In this talk, we present the results of realistic Monte Carlo simulations, performed with the GEANT4 toolkit, of the proton beam interaction in tissues in the presence of boron.
The efficacy of both the newly proposed PBCT and NCPET methodologies are discussed.
[1] P. Cirrone et al., Scientific Reports, 8 (2018) 1141
[2] A. Mazzone et al., Eur. Phys. J. Plus, 134 (2019) 361
[3] V. Jacobsen et al., Phys. Med. Biol. 70 (2025) 055008
[4] M. Safavi-Naeini et al., Scientific Reports 8 (2018) 16257
[5] R. Marino et al., in preparation