Summary:
The gamma knife is a highly specialized treatment unit that
provides an advanced sophisticated stereotactic approach
to treatment of tumour and vascular malformations within
the internal structure of the head. The gamma knife delivers
a single high dose of radiation emanating from 201 cobalt-
60 unit sources. All 201 beam simultaneously intersect at
the same time in a pre-defined location. The treatment
planning system for gamma knife radiosurgery has been
developed using nonlinear programming techniques. The
system optimizes the shot sizes, location and weights for
gamma knife treatments. Open stereotactic technique in the
1990’s was essential for the treatment of a number of
functional conditions and cystic space occupying lesions.
It has an important part to play in the investigation of
tumours and can help to increase the number which are
accessible to treatment. It can be employed to guide not
only solid instruments but also ionizing irradiation to “masslesion
– targets”. It is just this combination of stereotactic