Radiation therapy involves which of the following?

• A. Surgical removal of tumor
• B. Chemotherapy only
• C. Treatment with a radioactive substance, x-ray, or radiation
• D. Immunotherapy

Answer: (C)

Radiation therapy uses high-energy radiation to damage the DNA of cancer cells, preventing them from dividing and growing. This treatment can be delivered from outside the body as external beam radiation, or from radioactive materials placed inside the body near the tumor (brachytherapy). It is specifically about using radiation to target cancer cells, unlike surgical removal which physically cuts out the tumor, chemotherapy which uses chemical drugs, or immunotherapy which strengthens the immune system to fight cancer. With careful planning, radiation can shrink tumors or destroy cancer cells while minimizing damage to surrounding healthy tissue.