ABSTRACT
Radiation therapy is all about zapping tumors with ionizing radiation (Section 8.2). Since tumor cells are rapidly dividing, they are much more susceptible to death by radiation than other cells. X-rays are typically used, but electron and proton beams are also used for certain types of tumors. Since it is difficult or impossible to directly measure dose inside a patient during treatment, radiation therapists need to calculate doses, not only to the tumor, but also to the surrounding (healthy) tissue. When done properly, dose to the tumor is maximized, while dose to healthy tissue is minimized.
