Which device delivers gamma radiation from cobalt-60 to treat tumors?

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

Answer: (D)

Cobalt-60 gamma-ray radiotherapy relies on a gamma-emitting source to treat tumors. The device that delivers these gamma rays from cobalt-60 is a cobalt-60 unit, commonly known as a Gamma Knife. It places multiple cobalt-60 sources around the treatment area so beams converge on the tumor, delivering a precise, high-dose dose while sparing surrounding tissue.

Linear accelerators, by contrast, generate high-energy X-rays and are used for external beam radiotherapy, not gamma rays from cobalt-60. Brachytherapy uses internal radioactive sources placed near or inside the tumor and typically involves isotopes other than cobalt-60.