Wilhelm Röntgen discovered X-rays over 100 years ago in Wurzburg, Germany. Like many contemporary physicists, he was studying what happened when energetic electrons were made to hit a target inside a vacuum tube. While Röntgen himself coined the "X" for unknown, the mysteries of these "Röntgen rays" were quickly unravelled and harnessed for medical purposes. Imaging the human body with X-rays is now one of a suite of methods used to detect disease, and, specifically, to identify malignant disease or cancerous tumours. Generations have now benefited from the ability to see inside the human body effortlessly, painlessly and - at least in more recent years - almost instantaneously. As well as detecting disease, X-rays also provide the means for treatment: radiotherapy.
Both X-ray imaging and radiotherapy have evolved steadily over the past century, interspersed with several significant breakthroughs. Recently innovations in therapeutic radiology aim to improve the way in which X-rays are delivered to diseased tissue, in the hope of treating a greater range of tumours more effectively than ever before.
In the November issue of Physics World, Steve Webb from the Institute of Cancer Research in London writes about a new form of cancer treatment known as intensity-modulated radiation therapy.