It is through these holes that the radiation is focused on the target. The patient is precisely positioned by a neurosurgeon or radiation oncologist within the collimator helmet. The patient is then ready to undergo the treatment part of the procedure. Gamma Knife radiosurgery is virtually painless. And because the procedure does not require an incision, the usual risks of surgery and anesthesia are eliminated.
Patients experience minimal discomfort and can usually resume within one to three days.
Cobalt 60 radioactive sources are housed in a large lead shield shaped like a ball that weighs more than 20 tons. Certain functional disorders such as trigeminal neuralgia, intractable pain and certain psychiatric disorders can also be treated using the Gamma Knife. New indications such as epilepsy and Parkinson's disease are currently under evaluation. The success of the Gamma Knife is unprecedented. Through 1996, more than 58,766 patients worldwide received Gamma Knife radiosurgery with no mortality and minimal morbidity reported.