After imaging is completed, the radiation oncologist will meet with the medical physicist and dosimetrist to design a treatment plan that's been customized for you. After taking into account the location and type of cancer you have, your medical history, lab tests, and other factors, your treatment team will use sophisticated computer software to assist them in prescribing the exact volume to be treated, the total amount of radiation that will be delivered to the tumor, the angles for the radiation beams, how many treatments you should have, and what kind of machine to use.
Your oncologist will explain to you that the rectum should be empty and bladder full for treatment. You may be required to drink liquids before treatment for this reason. Some oncologists also prescribe a specific diet to be followed during the treatment course.