A linear accelerator (LINAC) is the device most commonly used for external beam radiation treatments for patients with cancer. The linear accelerator can also be used in stereotactic radiosurgery within the brain. It can also be used to treat areas outside of the brain.

It delivers a uniform dose of high-energy x-ray to the region of the patient's tumor. These x-rays can destroy the cancer cells while sparing the surrounding normal tissue.

In addition, it is used to provide Intensity-Modulated Radiation Therapy (IMRT).