Measurement of Absorbed Dose
Measurement of Absorbed Dose 8.1. Radiation Absorbed Dose In Chapter 6, the quantity exposure and its unit, the roentgen (C/kg), were discussed. It was then pointed out that exposure applies…
Electron Beam Therapy
Electron Beam Therapy High-energy electrons have been used in radiation therapy since the early 1950s. Originally, the beams were extracted mostly from betatrons, although a few linear accelerators and Van…
Dose Distribution and Scatter Analysis
Dose Distribution and Scatter Analysis It is seldom possible to measure dose distribution directly in patients treated with radiation. Data on dose distribution are almost entirely derived from measurements in…
Brachytherapy
Brachytherapy Brachytherapy is a method of treatment in which sealed radioactive sources are used to deliver radiation at a short distance by interstitial, intracavitary, or surface application. With this mode…
Intensity-Modulated Radiation Therapy
Intensity-Modulated Radiation Therapy 20.1. Introduction In the traditional external beam photon radiation therapy, most treatments are delivered with radiation beams that are of uniform intensity across the field (within the…
Treatment Planning II: Patient Data, Corrections, and Setup
Treatment Planning II: Patient Data, Corrections, and Setup Basic depth dose data and isodose curves are usually measured in a cubic water phantom having dimensions much larger than the field…
A System of Dosimetric Calculations
A System of Dosimetric Calculations Several methods are available for calculating absorbed dose in a patient. Two of these methods using percent depth doses and tissue-air ratios (TARs) were discussed…
Intravascular Brachytherapy
Intravascular Brachytherapy 24.1. Introduction Coronary artery disease is most commonly treated using bypass surgery or percutaneous transluminal coronary angioplasty (PTCA). A major problem with PTCA, however, is the high incidence…
Three-Dimensional Conformal Radiation Therapy
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
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…
