EBRT is a “local” treatment, which means it treats only a specific area of your body, not your whole body. For example, if you have prostate cancer, it will only treat your prostate. This alleviates some of the side effects of other whole-body treatments.
Using sophisticated treatment planning software, your radiation oncology treatment team plans the size and shape of the beam, as well as how it is directed at your body. This effectively treats your tumor while sparing the normal tissue surrounding the cancer cells.
The most common type of machine used to deliver external beam radiation therapy is called a linear accelerator, sometimes called a “linac.” It produces a beam of high-energy X-rays or electrons.
Several special types of external beam therapy are discussed below. These are used for particular types of cancer. Your radiation oncologist will recommend one of these treatments if he or she believes it will help you.
This precise location where you’ll receive treatment is called the treatment field or treatment part. To identify the treatment field, your radiation therapist will direct imaging scans of the area where your tumor is. Using these scans, he or she will determine the exact treatment part.
Once they identify the treatment field, your radiation therapist will mark it with semi-permanent ink. The marks will only be about the size of a freckle. It is very important that you receive treatment in the exact same area every time, so do not try to scrub away any markings left by your cancer care team. If the markings begin to fade, let your radiation therapist know.
In addition to these markings, you may require additional tools to stay in place. Depending on the location of your tumor, your team may use a specially made mold or mask to hold your body part in place.
All of these strategies are intended to precisely deliver your dose of radiation to the exact same spot during every treatment. Doing so not only guarantees the accuracy of your treatment, it also protects surrounding tissues from being unnecessarily affected by your radiation.
Radiation is usually delivered once daily, Monday through Friday. The weekends away allow cells to recover and the body to rest. These treatments usually last five to eight weeks. However, depending on your cancer, you may receive two treatments a day, or your treatment schedule may last longer.
Each daily treatment will only take a few minutes. Including time to position your body and the EBRT machine, each appointment will take 15 to 30 minutes.