External Beam Radiation Therapy

When you undergo external beam radiation therapy treatment, each session is painless, just like getting an X-ray. The radiation is directed at your tumor from a machine located away from your body, usually a linear accelerator. External beam radiation is noninvasive, unlike surgery which is an invasive process. One of the benefits of radiation therapy is that it is usually given as a series of outpatient treatments (meaning you don’t have to stay in the hospital). You may not need to miss work or experience the type of recuperation period that may follow other treatments.
Treatments are usually scheduled five days a week, Monday through Friday, and continue for one to 10 weeks. The number of radiation treatments you will need depends on the size, location and type of cancer you have, the intent of the treatment, your general health and other medical treatments you may be receiving.

The radiation therapist will give you your external beam treatment following your radiation oncologist’s instructions. It will take five to 15 minutes for you to be positioned for treatment and for the equipment to be set up. If an immobilization device was made during simulation, it will be used during every treatment to make sure that you are in the exact same position every day.

Once you are positioned correctly, the therapist will leave the room and go into the control room next door to closely monitor you on a television screen while giving the radiation. There is a microphone in the treatment room so you can always talk with the therapist if you have any concerns. The machine can be stopped at any time if you are feeling sick or uncomfortable.

The radiation therapist may move the treatment machine and treatment table to target the radiation beam to the exact area of the tumor. The machine might make noises during treatment that sound like clicking, knocking or whirring, but the radiation therapist is in complete control of the machine at all times.

The radiation therapy team carefully aims the radiation in order to reduce the dose to the normal tissue surrounding the tumor. Still, radiation will affect some healthy cells. Time between daily treatments allows your healthy cells to repair much of the radiation effect, while cancer cells are not as likely to survive the changes.

Sometimes a course of treatment is interrupted for a day or more. This may happen if you develop side effects that require a break in treatment. These missed treatments may be made up by adding treatments at the end. Try to arrive on time and not miss any of your appointments. Time spent in the treatment room may vary depending on the type of radiation, but it generally ranges from 10 to 40 minutes. Most patients are treated on an outpatient basis, and many can continue with normal daily activities.

Your radiation oncologist monitors your daily treatment and may alter your radiation dose based on these observations. Also, your doctor may order blood tests, X-rays and other tests to see how your body is responding to treatment. If the tumor shrinks significantly, another simulation may be required. This allows your radiation oncologist to change the treatment to destroy the rest of the tumor and spare even more normal tissue.

Weekly Status Checks

During radiation therapy, your radiation oncologist and nurse will see you regularly to follow your progress, evaluate whether you are having any side effects, recommend treatments for those side effects (such as medication) and address any concerns you may have. As treatment progresses, your doctor may make changes in the schedule or treatment plan depending on your response or reaction to the therapy.

Your radiation therapy team may gather on a regular basis with other healthcare professionals to review your case to ensure your treatment is proceeding as planned. During these sessions, all the members of the team discuss your progress as well as any concerns.

Weekly Beam Films

During your course of treatment, correct positions of the treatment beams will be regularly verified with images made using the treatment beam itself. These images (called port films, beam films or portal verification) represent an important quality assurance check, but do not evaluate the tumor itself.