The non-orthogonal fixed beam arrangement for the second proton therapy facility at the National Accelerator Center

Abstract

The medical user group at the National Accelerator Center (NAC) is currently unable to treat all eligible patients with high energy protons. Developing a second proton treatment room is desirable since the 200 MeV proton beam from the NAC separated sector cyclotron is currently under-utilized during proton therapy sessions. During the patient positioning phase in one treatment room, the beam could be used for therapy in a second room. The second proton therapy treatment room at the NAC will be equipped with two non-orthogonal beam lines, one horizontal and one at 30 degrees to the vertical. The two beams will have a common isocentre. This beam arrangement together with a versatile patient positioning system (commercial robot arm) will provide the radiation oncologist with a diversity of possible beam arrangements and offers a reasonable cost-effective alternative to an isocentric gantry.