A linear accelerator (LINAC) is a device that uses high-frequency electromagnetic waves to accelerate electrons to high energies in a linear path inside an accelerator waveguide. LINACs are commonly used for external beam radiation therapy to treat cancer. LINACs work by using microwave technology to accelerate electrons, which are then directed at a target to produce high-energy x-ray or electron beams. The beams exit the machine shaped to the tumor and can be delivered from any angle by rotating the gantry and moving the treatment couch. LINACs are used to plan and deliver targeted radiation treatments to destroy cancer cells while sparing surrounding healthy tissue.