Image Modulated Radiation Therapy (IMRT)

The linear accelerator uses microwave technology to accelerate electrons in a part of the accelerator called the “wave guide,” this then allows these electrons to collide with a heavy metal target to produce high-energy x-rays. These high energy x-rays are shaped as they exit the machine to conform to the shape of the patient’s tumor and the customized beam is directed to the patient’s tumor. The beam is usually shaped by a multileaf collimator that is incorporated into the head of the machine. The patient lies on a moveable treatment couch and lasers are used to make sure the patient is in the proper position. The treatment couch can move in many directions including up, down, right, left, in and out. The beam comes out of a part of the accelerator called a gantry, which can be rotated around the patient. Radiation can be delivered to the tumor from many angles by rotating the gantry and moving the treatment couch.

The time a patient spends in the treatment room depends on the specific plan, but usually is between 15 minutes and one hour.