The physics of radiation treatment

X-rays are now routinely used to diagnose and treat disease, and researchers are now developing new techniques that will make x-ray treatment more effective than ever before. Successful radiotherapy requires two key components: finding the precise location of the tumor and concentrating radiation on it to destroy the diseased tissue. The recent treatment would be to move the leaves of the multi leaf collimator under computer control, dynamically varing the speed of all the leaf pairs with time as they sweep across the required geometrical shape. The other method is to arrange for carefully engineered pieces of x-ray tungsten to move into and out of the radiation field for precisely controlled periods of time, driven electro pneumatically and controlled by a computer. (author)