Typically administered in daily fractions in the range of .8-2.0 Gy to a total dose of 60-7- Gy.
Computerized tomography coupled with radiation treatment planning computers allows for precise identification of target tissues and orientation of treatment beam.
3-dimensional target definition allows radiation fields to conform to the shape of treatment volume and allows delivery of treatment to the intended area while avoiding or minimizing exposure to normal structures.
Tissue overlying and underlying a tumor will also be irradiated with the tumor during external beam radiation.
External beam radiation therapy utilizes a source that is a distance from the patient.