EXTERNAL BEAM RADIATION THERAPY

External Beam Radiation Therapy

External beam radiation therapy comes from a machine that aims radiation at your cancer. It is a local treatment, which means it treats a specific part of your body. For example, if you have cancer in your lung, you will have radiation only to your chest, not to your whole body.

External beam radiation therapy is used to treat many types of cancer.

Types of External Beam Radiation Therapy

There are many types of external beam radiation therapy, all of which share the goal of delivering the highest prescribed dose of radiation to the tumor while sparing the normal tissue around it. Each type relies on a computer to analyze images of the tumor in order to calculate the most precise dose and treatment path possible.

IMRT

Intensity-modulated radiation therapy

IGRT

Image-guided radiation therapy

SBRT

Stereotactic body radiation therapy

What to Expect When Having External Beam Radiation Therapy

How Often You Will Have External Beam Radiation Therapy

Most people have external beam radiation therapy once a day, five days a week, Monday through Friday. Radiation is given in a series of treatments to allow healthy cells to recover and to make radiation more effective. How many weeks you have treatment depends on the type of cancer you have, the goal of your treatment, the radiation dose, and the radiation schedule.

The span of time from your first radiation treatment to the last is called a course of treatment.

Where You Go for External Beam Radiation Therapy

Most of the time, you will get external beam radiation therapy as an outpatient. This means that you will have treatment at a clinic or radiation therapy center and will not stay the night in the hospital.

What to Wear for Your Treatments

Wear clothes that are comfortable and made of soft fabric, such as fleece or cotton. Choose clothes that are easy to take off, since you may need to expose the treatment area or change into a hospital gown. Do not wear clothes that are tight, such as close-fitting collars or waistbands, near your treatment area. Also, do not wear jewelry, adhesive bandages, or powder in the treatment area.

What Happens During a Treatment Session

The radiation therapist will leave the room just before your treatment begins. He or she will go to a nearby room to control the radiation machine. The therapist watches you on a TV screen or through a window and talks with you through a speaker in the treatment room. Make sure to tell the therapist if you feel sick or are uncomfortable. He or she can stop the radiation machine at any time. You will hear the radiation machine and see it moving around, but you won’t be able to feel, hear, see, or smell the radiation.

Most visits last from 30 minutes to an hour, with most of that time spent placing you in the correct position.