[en] For radiation therapy at medium and high energies the circular and the racetract microtron are ideally suited electron accelerators. The fine energy definition of the electron beam from a microtron allows the use of beam transport from one accelerator to several treatment units. This possibility makes an installation with two or more treatment rooms very interesting from an economical point of view particularly at high energies. The availability of high quality radiation modalities from the compact high energy racetrack microtron may open new possibilities in the treatment of large deep seated tumours