Medically reviewed by Dr. T. Rhett Spencer
Bulky machines sit in a darkened room. A bed stretches into the inside of the machine. It may buzz or hum. These machines that direct radiation into cancer are one of the most effective ways to kill, control or shrink tumors. External Beam Radiation Therapy, Radiotherapy or Cancer Radiation Therapy uses the large machines to generate high energy, highly targeted x-ray, cobalt or particle beams. The beams are focused to hit the tumors inside the body, disrupting the DNA in the tumor. The goal is to kill the tumor cells so that the body sloughs them off. Treatments are generally painless and the machine doesn’t touch the patient nor does it make the patient radioactive.