The Treatment Room and Maze Design for Medical Accelerators

This paper analyses the shielding design of medical accelerators. To find the best plan among them, which need the lowest cost to obtain the same effect, some theoretical calculations according to the recommended methods of NCRP 151 report have been done. The paper also compares the effects on dose equivalent at the maze door when beam direction is parallel or perpendicular to the maze wall separately. Then it concludes that the photon dose at the maze door will be lower by a factor of one magnitude if the door locates at the side of the maze but not at the terminal of it. In addition, the neutron capture γ-ray and the photo neutron dose will also be greatly reduced in this situation. It should be pointed out that the beam directly hitting the maze wall is not a recommended design, although it can meet the final dose standard. Since more and more medical accelerators are used in radiotherapy, this work may be helpful to the medical accelerator shielding design both for maze and treatment room.