Muons versus Hadrons for Radiotherapy

Intense low energy muon beams – as part of a muon collider complex – may become available for use in radiotherapy. It is of interest to compare their effectiveness in this application with that of hadron beams in a setting where processes common to these beams are treated exactly alike. Detailed simulations of physics processes for muon, proton, antiproton, neutron, kaon and pion beams stopping in various media have been performed using the MARS code with newly developed weighted algorithms. Special attention is paid to μ−, π−, and p capture on light nuclei. Calculated distributions of energy deposition and dose equivalent due to processes involvingprimary beams and generated secondaries are presented for a human tissue-equivalent phantom (TEP). The important ratio of dose delivered to healthy tissue vs dose to tumor is examined within this model. The possibility of introducing heavier elements into the tumor to increase capture of stopped μ− is briefly explored.