Your first IMRT treatment session may last longer than subsequent appointments because your doctor may perform additional x-ray exams and checks. A typical IMRT session lasts about 15 to 20 minutes, the same amount of time required for a standard radiation treatment. In the treatment room, you will see a large machine called a linear accelerator which will deliver the radiation beams. It can be rotated around your body with great precision. Using the semi-permanent ink marks on your skin made during the planning session, the radiation therapist will position you on the table below the machine. Before the machine is turned on, the radiation therapist will leave the room. Although the linear accelerator is controlled remotely, the therapist can still see and talk to you. You will not see or hear the radiation and usually will not feel anything.