Development of the Gamma Knife

Abstract

The first Gamma Knife was constructed after more than two decades of research, in both the laboratory and the clinic. The primary intention, at the start of this research was as indicated in chapter 1, non-invasive treatment, rather than a commitment to a particular technology. Ultrasound was considered and rejected, because at that time it could not be used with precision without opening the skull. Leksell’s first paper with the word radiosurgery in the title was published in 1951. Thus, the concept of a non-invasive surgical procedure and the development of a simple usable stereotactic system seem to have been contemporary. Moreover, it is easy to forget today, when the major indications for Gamma Knife surgery are tumours and malformations, that the limits of imaging techniques applying to open stereotaxy also apply to radiosurgery. In the nineteen fifties and sixties radiological tumour delineation was approximate, seen in relation to the precision of stereotactic treatment. Thus, the early experimental work was performed and the first clinical instruments were designed with a view to making cerebral lesions, for treating functional disorders. It seems likely that it was considered particularly important to avoid the potential dangers of surgery when treating conditions which did not present a short term threat to life.