Varian Linear Accelerator

A linear accelerator (LINAC) is the device most commonly used for delivering external radiation therapy. It uses a variety of methods to customize high energy x-rays to match an individual tumor’s shape so that radiation can be delivered as precisely as possible. This allows your doctor to more accurately target and destroy cancer cells while protecting surrounding healthy tissue, making cancer treatment more effective, with fewer side effects from damage to healthy tissue. Martin O’Neil uses a state-of-the-art accelerator made by Varian.

How does the equipment work?

The linear accelerator can be used to treat solid tumors in all areas of the body.

Your radiation oncologist will use a variety of diagnostic techniques to determine as exactly as possible the size, shape and location of your tumor, and determine the radiation dosage to be used. The medical radiation physicist and the dosimetrist then determine how to deliver the prescribed dose and calculate the amount of time it will take. The LINAC will then be set to customize the shape of the radiation beam to conform to your individual tumor. Using a microwave technology similar to that used in radar, the LINAC’s “wave guide” then accelerates electrons, and sends them to collide with a heavy metal target to produce high-energy x-rays. As they exit the machine, the x-rays are shaped to match the outlines of your tumor, and directed toward the tumor area.

The treatment plan is double-checked before treatment is given, and the LINAC uses a number of internal safety measures to ensure that the beam cannot exceed the prescribed dose, and a variety of means to ensure that targeting remains precise.

To receive your treatments, you will lie on a moveable treatment couch beneath a part of the accelerator called a gantry. Your radiation therapist will use lasers to ensure that your treatment area is precisely located, and provide ways to help you remain in position. Radiation can be targeted to any area of the body from any angle by rotating the gantry and moving the treatment couch. You will be continuously monitored by the technologist for position and comfort.