The light at the end of the tunnel as can be seen when patients enter the treatment bunker in Erasmus MC's newest linear accelerator situated in Dordrecht, Netherlands. This machine is used for external beam radiotherapy, otherwise known as teletherapy, the most frequently used form of radiotherapy. The patient sits or lies on a couch and an external source of radiation is pointed at a particular part of the body. In contrast to internal radiotherapy (brachytherapy), in which the radiation source is placed inside the body, external beam radiotherapy directs the radiation at the tumor from outside the body. This machine is called "Pegasus" (full set of Pegasus photos here Original here. (© Vincent Riemersma