What device is most commonly used in a medical setting to administer radiation?

In a medical setting, the linear accelerator is a key device used for administering radiation, particularly for cancer treatment through techniques like external beam radiation therapy. Linear accelerators produce high-energy x-rays or electrons that target tumors while minimizing exposure to surrounding healthy tissue, making them critical in radiation therapy.

Though x-ray machines are also employed in medical imaging and diagnostics, they primarily serve a different purpose, focusing on capturing images rather than administering therapeutic doses of radiation. Ultrasound scanners and magnetic resonance imaging (MRI) are imaging modalities that do not involve ionizing radiation; instead, they use sound waves and magnetic fields to create images of the body, respectively. Therefore, when discussing medical devices specifically employed for radiation administration in a treatment context, the linear accelerator stands out as the most commonly used option.