You are on a good program. This is called IMRT and it uses very sophisticated software to control the angles of the radiation beam, and a special shuttering system inside the radiation head to narrow the beam. The computer calculates form your CT scans the best angles to get at the tumor without hitting the major salivary glands, or at least exposing them to less radiation. A company called Varian developed the technology. (They call it Smart Beam) Look on the OCF web site in the news section, and under radiation for more information on this. Then if you really want the nuts and bolts of it, look through your search engine and find the site for Varian on the web. The reduction in xerostomia from this technique is well documented, and for those who have tumors that fit into the protocols size range, or which are located in the in areas where it can be used, it is a big step forward in technology.