The Linear Accelerator: What Is It and How Does It Work

A linear accelerator (LINAC) is a machine most often used for delivering external radiation therapy to those dealing with cancer. The device uses a variety of methods to customize high energy x-rays to mirror an individual tumor’s shape so that radiation can be administered as accurately as possible. 

LINAC devices efficiently target and destroy cancer cells while protecting surrounding healthy tissue, making this type of treatment more effective with fewer side effects. 

How exactly does this equipment work?

The linear accelerator is used to treat solid tumors in all areas of the body. A radiation oncologist will run several diagnostic measures to determine the size, shape, and location of the tumor. Afterward, the oncologist will determine what level of radiation dosage will be used. The media radiation physicist and dosimetrist will evaluate how to deliver the prescribed amount of radiation and calculate the amount of time it will take to administer over time. 

After the preliminary diagnostics for administration are prescribed, the LINAC is adjusted and customized to fit the shape of the radiation beam to conform to the individual tumor properties. Using microwave technology similar to that used in radar, the LINAC’s “waveguide,” then accelerates electrons and sends them to collide with a heavy metal target to produce high-energy x-rays. As the rays exit the machine, they are shaped to match the tumor's outlines and directed towards the tumor area.

Specific protocols and safety measures are conducted to ensure that the beam cannot exceed the prescribed dose or travel outside of the pre-determined bounds that could damage healthy skin. 

During the treatment, you will lie on a moveable couch or seat beneath a part of the linear accelerator called a gantry. Your radiation therapist will use lasers to ensure that your treatment area is administered precisely. Your radiation therapist will also assist in helping your body to remain positioned for optimum beam exposure to the right areas. 

Radiation can be focused on any area of the body from any angle by rotating the gantry and moving the treatment couch. During treatment, you will be continuously monitored by the technologist for position, accuracy, and comfort. 

Reference Link: https://www.adventisthealth.org/cancer-center/our-technology/varian-linear-accelerator/