Three-Dimensional Conformal Radiation Therapy 19.1. Introduction By three-dimensional conformal radiotherapy (3-D CRT), we mean treatments that are based on 3-D anatomic information and use dose distributions that conform as closely…
High-Dose-Rate Brachytherapy 22.1. Introduction Most of the clinical experience in brachytherapy has been obtained using low-dose-rate (LDR) implants, that is, with prescription dose rate on the order of 0.5 to…
Prostate Implants 23.1. Introduction Treatment options for carcinoma of the prostate include radical prostatectomy (e.g., nerve-sparing surgical procedure), external photon beam irradiation, and brachytherapy implantation. The selection of a particular…
Proton Beam Therapy 26.1. Basic Physics A. Nature of the Particle According to the Big Bang Theory, hydrogen was the first element to form in the universe (∼100 seconds after…
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…
