Physics and Clinical Aspects of Brachytherapy

摘要: Brachytherapy was the original intensity‐modulated radiotherapy, providing ability to deliver high doses custom‐shaped targets while preserving normal, neighboring structures. has many manifestations, for example permanent implants and treatments using high‐dose rate remote afterloaders. The may be executed by placement of needles or catheters into a tumor sources in body cavities near tumor. choice sources, approaches techniques should dictated patient’s presentation. treatment delivery affects both biological results radiation physical facets therapy. Biologically, low‐dose tend relatively gentler normal tissues but provide more stable precise dose distributions. Most commonly, distribution calculations follow protocol Task Group 43 American Association Physicists Medicine, computing rates space from each source separately adding them together obtain composite. At time writing, commercial planning systems have just begun incorporate computational algorithms that can include effects tissue composition density. moved simple localization planar images radiographs identify positions skeletal anatomy volume imaging also shows soft allows identification target Physiological molecular further enhance shape volumes, as with external‐beam treatments. Treatment entails decisions on approach brachytherapy. classical systems, such Paris Manchester guidance needle distributions controlled modern optimization routines. These along other measures implant quality, serve benchmarks quality‐assurance evaluations an application.