ABSTRACT
Teletherapy, sometimes called external beam radiotherapy, is the treatment of cancer using apparatus such as a deep therapy X-ray machine, linear accelerator or cobalt-60 machine. Because of the lack of penetration of the X-ray beams from the early therapy apparatus, the initial years of X-ray therapy although recording successes with superficial tumours were not satisfactory for the treatment of deep-seated tumours. The glass cylinder is probably an attempt to limit the X-ray beam to the area prescribed for treatment and is therefore one of the earliest attempts at collimation. However, unless it was made of lead glass, which is not known, it would have been unsuccessful. The chapter discusses a Brown-Boveri radiotherapy betatron in the early 1980s: the Asklepitron 45. The betatron was used in two modes, X-ray beam or electron beam. Applicators are used for the electron mode.
