Clinical and practical applications of radiation therapy: when should radiation therapy be considered for my patient?

Radiation therapy uses high-energy radiation from X-rays, γ-rays, neutrons, electrons, protons and other sources to kill cancer cells and shrink tumours. External-beam radiation therapy (EBRT) is delivered by a machine outside the body, while brachytherapy or internal radiation therapy comes from radioactive material placed in the body near or within the tumour. EBRT is the most common method of delivering radiation treatment. Curative and palliative treatment regimens are usually given on an outpatient basis over 1–8 weeks.