External beam therapy is the most common form of radiotherapy, delivering ionizing radiation such as high-energy x-rays, gamma rays or electron beams directly into the location of the patient's tumour. The beam is generated externally, with no radioactive sources placed within the patient'sbody. The beams aim at destroying the cancer cells with minimal impact on the surrounding healthy tissue. The radiation oncologist will choose between different ways of administering the beams, such as linear accelerators, cobalt machines, or ortho-voltage x-ray machines. The three distinctstages of simulation, planning and treatment are critical to ensuring the highest rate of success. This book is an essential, practical guide to the use of external beam radiotherapy, highlighting the rapid technological advances made in recent years. It provides a firm background to the physics of external beam radiotherapy, taking the reader through the basic principles and discussing issuessuch as quality assurance. Experts within each field then expand upon techniques for treatment delivery within each anatomical site, covering indications, treatment and planning. ABOUT THE SERIES Radiotherapy remains the major non-surgical treatment modality for the management of malignant disease, with over 50% of patients receiving treatment at some time during the management of their malignant disease. It is based on the application of the principles of applied physics, radiobiology, andtumour biology to clinical practice. Each volume in this series takes the reader through the basic principles of different types of radiotherapy, and then develops these by individual sites. This series of practical handbooks are aimed at physicians both training and practising in radiotherapy, aswell as medical physicists, dosimetrists, radiographers and senior nurses.