Treatment Planning III: Field Shaping, Skin Dose, and Field Separation Shielding of vital organs within a radiation field is one of the major concerns of radiation therapy. Considerable time and…
Image-Guided Radiation Therapy 25.1. Introduction Broadly, image-guided radiation therapy (IGRT) may be defined as a radiation therapy procedure that uses image guidance at various stages of its process: patient data…
Treatment Planning I: Isodose Distributions The central axis depth dose distribution by itself is not sufficient to characterize a radiation beam that produces a dose distribution in a three-dimensional volume….
Stereotactic Radiosurgery 21.1. Introduction Stereotactic radiosurgery (SRS) is a single-fraction radiation therapy procedure for treating intracranial lesions using a combination of a stereotactic apparatus and narrow multiple beams delivered through…
Radiation Protection Radiation exposure limits or standards were introduced as early as the start of the 20th century when the potential hazards of radiation were realized. One of the first…
Total Body Irradiation Total body irradiation (TBI) with megavoltage photon beams is most commonly used as part of the conditioning regimen for bone marrow transplantation, which is used in the…
Interactions of Ionizing Radiation When an x- or γ-ray beam passes through a medium, interaction between photons and matter can take place with the result that energy is transferred to…
Quality Assurance The term quality assurance (QA) describes a program that is designed to control and maintain the standard of quality set for that program. For radiation oncology, a quality…
Measurement of Ionizing Radiation 6.1. Introduction In the early days of x-ray usage for diagnosis and therapy, attempts were made to measure ionizing radiation on the basis of chemical and…
Nuclear Transformations 2.1. Radioactivity Radioactivity, first discovered by Antonio Henri Becquerel (1852–1908) in 1896, is a phenomenon in which radiation is given off by the nuclei of the elements. This…
