What type of therapy is primarily used for treating cancer by using high doses of radiation?

Radiation therapy is a method that uses high doses of radiation to target and destroy cancer cells. The fundamental principle behind radiation therapy is to damage the DNA of these cells, leading to their inability to grow and divide. Unlike other treatment modalities such as surgery, which involves physically removing cancerous tissue, or chemotherapy, which uses drugs to kill rapidly dividing cells throughout the body, radiation therapy is specifically focused on using ionizing radiation to induce cell death in localized tumor areas.

This targeted approach makes radiation therapy an essential component of cancer treatment, either as a primary treatment to shrink tumors or in conjunction with other therapies to enhance overall treatment effectiveness. It's especially useful for treating cancers that are localized and can be pinpointed effectively with radiation.

In contrast, immunotherapy works by stimulating the body's immune system to combat cancer cells; surgery is invasive and not always applicable; chemotherapy, while effective against many cancer types, distributes systemic drugs that can affect healthy cells along with cancer cells, leading to a different set of side effects and mechanisms of action. Thus, radiation therapy is distinctly characterized by its use of high-dose radiation, setting it apart from the other treatment options.