Radiation Therapy (Radiotherapy) is a fundamental medical treatment modality that utilizes high-energy radiation to eradicate or inhibit the proliferation of cancer cells. It typically employs X-rays or Gamma rays to induce DNA damage within malignant cells, thereby disrupting their replicative capacity.

As a primary oncological intervention, radiotherapy is frequently administered alongside surgical resection or chemotherapy to optimize therapeutic efficacy. Clinical administration involves various modalities, most notably External Beam Radiation Therapy (EBRT) and internal radiation (Brachytherapy).

Radiation oncologists meticulously formulate treatment plans to maximize the targeted destruction of malignant cells while strictly minimizing exposure to adjacent healthy tissues.

Key clinical advantages include highly localized treatment, the potential avoidance of invasive surgery in specific indications, and tumor downstaging (size reduction) prior to subsequent therapies. However, patients may experience adverse effects, such as radiation dermatitis at the treatment site, systemic fatigue, or collateral toxicity to proximal organs.

Ultimately, radiation therapy remains a pivotal technology in modern oncology, significantly improving therapeutic outcomes and enhancing the long-term quality of life for cancer patients.