What term describes the use of external beam radiation to treat tumor tissues?

• A. Brachytherapy
• B. External Beam
• C. Linear Accelerators
• D. Gamma Knife

Answer: (B)

The key idea here is how radiation is delivered. When radiation is produced outside the body and directed at the tumor, the procedure is described as external beam radiation therapy. This approach uses machines such as linear accelerators to generate high-energy beams that are aimed at the tumor from outside, often with precise imaging to focus the dose and spare normal tissue. That contrasts with brachytherapy, which delivers radiation from within the body by placing radioactive sources directly near or inside the tumor. The gamma knife is a specialized form of focused external radiotherapy used for certain brain lesions, but the broad term that matches the description of “use of external beam radiation” is external beam radiation therapy.