Fundamentals of Radiation Dosimetry

Abstract

Ionizing radiation is used in many aspects of modern life: in science, industry, power generation, and medicine. In medicine it is used in diagnosis of disease with x-rays and gamma rays (imaging) as well as in treatment of malignant disease with high energy x-rays, electrons, and heavy charged particles. Measurement of quality and quantity of ionizing radiation, referred to as radiation dosimetry, is the most important area of medical physics, essentially its “raison d’être”. This chapter provides a general introduction to radiation dosimetry starting with a discussion of physical quantities and units used for describing radiation sources and radiation beams. The chapter also introduces the concept of charged particle equilibrium, deals with radiation dosimetry systems and types of dosimeters, and introduces the basic cavity theories of radiation dosimetry. The chapter concludes with a brief discussion of the basic calibration of radiotherapy machine output and radiation dosimetry protocols.