A dedicated processor for Monte Carlo computations in radioteraphy

A dedicated processor for Monte Carlo computations in radiotherapy treatment planning on FPGA based hardware is being developed at INFN, Cagliari. When performing Monte Carlo simulations of the radiation dose delivered to the human body, the Compton interaction of a photon with an electron is simulated. A fast, pipelined, cost effective design for real time simulation of the Compton interaction had been implemented. The inputs to the system are the energy and the normalized direction vectors of the incoming photon. The energy and the direction vectors of the scattered photon and the scattered electron are calculated. The energy distribution by the scattered electron along its path in a voxel space is then calculated which can be used to construct maps of dose distribution in real time.