January 1st 2005
This chapter provides a brief overview of the principles of radiation therapy.The topics to be discussed include the physical aspects of how radiation works(ionization, radiation interactions) and how it is delivered (treatment machines,treatment planning, and brachytherapy). Recent relevant techniques of radiationoncology, such as conformal and stereotactic radiation therapy, also willbe presented. These topics are not covered in great technical detail, and noattempt is made to discuss the radiobiological effects of radiation therapy. It ishoped that a basic understanding of radiation treatment will benefit those practicingin other disciplines of cancer management. This chapter does not addressprinciples of radiobiology, which guide radiation oncologists in determiningissues of treatment time, dose, and fractionation or in combining radiationwith sensitizers, protectors, and chemotherapy or hormones.