Which approach uses external radiation to treat tumors without implanting sources inside the body?

Which approach uses external radiation to treat tumors without implanting sources inside the body?

• A. Brachytherapy
• B. Cobalt-60 Gamma Knife
• C. External Beam
• D. Linear Accelerators

Answer: (C)

External beam radiotherapy delivers radiation from outside the body to target a tumor. The key feature is that no radioactive sources are implanted inside the patient; the treatment uses machines outside the body to generate and direct high-energy rays toward the tumor. This distinguishes it from brachytherapy, where radioactive sources are placed inside or adjacent to the tumor. The cobalt-60 Gamma Knife is a specialized external beam approach that focuses rays onto a brain target using sources contained in the device, and linear accelerators are the common machines used to produce these external beams. So the option describing external radiation from outside the body best captures this approach.

External beam radiotherapy delivers radiation from outside the body to target a tumor. The key feature is that no radioactive sources are implanted inside the patient; the treatment uses machines outside the body to generate and direct high-energy rays toward the tumor. This distinguishes it from brachytherapy, where radioactive sources are placed inside or adjacent to the tumor. The cobalt-60 Gamma Knife is a specialized external beam approach that focuses rays onto a brain target using sources contained in the device, and linear accelerators are the common machines used to produce these external beams. So the option describing external radiation from outside the body best captures this approach.