What treatment involves using high-energy radiation to destroy cancer cells in breast cancer therapy?

Radiation therapy is a key treatment modality used in breast cancer therapy that employs high-energy radiation, such as X-rays or gamma rays, to target and destroy cancer cells. The primary goal of radiation therapy is to eliminate any remaining cancer cells post-surgery, shrink tumors before surgery, or alleviate symptoms in advanced stages of cancer. It works by damaging the DNA in cancer cells, which inhibits their ability to replicate and grow.

In breast cancer management, radiation is often used after lumpectomy or mastectomy to reduce the risk of recurrence. The precision of modern radiation techniques allows for targeted delivery of radiation to the tumor site while minimizing exposure to surrounding healthy tissue, thereby maximizing treatment efficacy while minimizing side effects.

The other treatment modalities mentioned have distinct mechanisms and purposes: chemotherapy involves using drugs to kill fast-growing cancer cells throughout the body; surgery physically removes tumors; and immune therapy works to boost the body's immune system to fight cancer. While all these options may play a role in breast cancer treatment, radiation therapy specifically addresses the destruction of cancer cells through high-energy radiation, which is why it is the correct answer in this context.