Radiosurgery is a technique that is used in the treatment of certain types of
tumors. SRS is used when a high degree of precision is required. This
additional precision is attained through rigid immobilization of the body part
to be treated, such as with a head frame that is used in the treatment of brain
Although usually performed in a single treatment, fractionated radiotherapy
(SRT) (delivery of up to five treatments), is sometimes used. In addition to
treating tumors, this method is sometimes used to treat malformations in the
brain's blood vessels and certain non-cancerous (benign) brain tumors.
The treatment involves the delivery of a single high-dose—or sometimes smaller,
multiple doses—of radiation beams that converge on the specific area of the
brain where the tumor or other abnormality resides. Using a helmet-like device
that keeps the head completely still and three-dimensional computer-aided
planning software, stereotactic radiosurgery minimizes the amount of radiation
to healthy brain tissue.
Treatment delivery can be done on a Gamma Knife, CyberKnife, or conventional
linear accelerator with specialized hardware.
Particle beam (proton) or cyclotron is in limited use in North America.
However, several new facilities are being built.