Formation of a Mixed Source of Epithelial Neutrons and a Scanning Proton Beam at the Prometheus CPT for the Treatment of Tumors in the Flash Therapy Mode

A mixed secondary beam of delayed neutrons and a scanning high-intensity pencil beam of protons are designed to irradiate the tumor in the flash therapy mode with a dose of 50–70 Gray on a Prometheus medical accelerator at an energy of 200 MeV. A neutron-forming target is used to produce fast neutrons and then delayed neutrons. The special design of the neutron-producing target allows the accelerator to irradiate the outer surface of the tumor with scanning spots of protons and simultaneously irradiate the entire tumor area with delayed neutrons with just a few pulses of the accelerator. Using the developed new composites for neutron protection, a mixed beam channel is constructed: delayed neutrons and scanning proton spots. The power profiles of the equivalent dose at the outlet of the channel for the neutron component of the channel are measured using an ionization pad chamber on a warm liquid (WL). The pencil proton beam, scanning the entire outer surface of the tumor and sequentially changing the scanning depth, should destroy the superficial blood vessels on the outer surface of the tumor. The average radiation dose per session should be 50–70 Gray. A neutron beam simultaneously with protons during a flash therapy session irradiates the entire tumor area and has a combined value, working in the mode of the neutron capture dose-forming component of this treatment method, in the presence of the introduction of the desired sensitizer. It is proposed to enhance the effect of a proton beam scanning the tumor surface by additional dose generation from radio sensitizers based on gold nanoparticles.