Monte Carlo Simulations Of The Dose Distributions From Carbon Microbeams Used In An Experimental Radiation Therapy Method

Recent upgrades of the MCNPX Monte Carlo code include transport of heavy ions. We employed the new code to simulate the energy and dose distributions produced by carbon beams in rabbit’s head in and around a brain tumor. The work was within our experimental technique of interlaced carbon microbeams, which uses two 90° arrays of parallel, thin planes of carbon beams (microbeams) interlacing to produce a solid beam at the target. A similar version of the method was earlier developed with synchrotron‐generated x‐ray microbeams. We first simulated the Bragg peak in high density polyethylene and other materials, where we could compare the calculated carbon energy deposition to the measured data produced at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL). The results showed that new MCNPX code gives a reasonable account of the carbon beam’s dose up to ∼200 MeV/nucleon beam energy. At higher energies, which were not relevant to our project, the model failed to reproduce the Bra...