What is Radiation Therapy

Radiation therapy, also called radiotherapy, is the branch of medicine that deals with the treatment of cancer by delivering high-energy beams directly to a tumor, or intended target.

Radiation therapy is a common form of treatment for cancer today. According to the American Society of Radiation Oncology (ASTRO), two out of three cancer patients will receive radiation therapy-either alone or in combination with other treatment approaches, such as surgery and chemotherapy. Each case is unique and your health care provider is the best person to decide on the suitability of radiation therapy for your treatment.

Radiation therapy has two equally important goals: to control the growth of the tumor and to do so while minimizing exposure to the surrounding normal, healthy tissue.

How does radiation work?

Radiation therapy uses a focused beam of energy to damage cancerous cells while minimizing exposure to healthy tissue. Radiation damages the DNA in cancer cells, which interrupts their ability to reproduce, causing them to die and the tumor to shrink. Normal cells can recover from radiation more easily.

Treatment is delivered to the target site with a machine called a linear accelerator, or linac. The linac generates a high-energy beam, which is delivered from many different angles, to target each part of the tumor and deliver the prescribed amount of radiation. Typically, treatment is delivered five days a week over several weeks.