In the field of Medical Simulation, MCNP5 and MCNPX programs developed by Los Alamos National Laboratory to simulate the radiation machines such as the head of accelerator, X-rays tube, cyclotron...are used. From these models, the characteristics of emitted radiation: the energy spectrum, the percentage depth dose, the off-axis dose, calculating the absorbed dose in the tumour in the simple cases, the dose distribution inside and outside the room...are evaluated. The radiation safety for technician and people arround outside the room are also investigated.
