INTRODUCTION: Leksell Gamma Knife Perfexion is  the GOLD STANDARD for Stereotactic Radiosurgery of tumors, malformations and other functional disorders of brain and head. First Gamma Knife was installed in 1968 at Sophiahemmet, Stockholm Sweden. Since then it has grown with availability of new technology and kept edge over other systems foe radiosurgical treatments due to high precision , safety standards and good results.

EVOLUTION of GAMMA KNIFE: Leksell Gamma Knife  Model U was commercially available since 1986. In 1996 a redesigned Model B was launched. Model C was upgrade over Model B with nearly same core designing. In 2004 Model C was further automated to Model 4C with development of automatic positioning system [APS]. This introduced robotic micro-adjustable radiosurgery for the first time but still had various limitation of Model D due to shape of collimators , limited reach to skull base and collision in extreme positions. Also radiation to normal body parts was under scrutiny and point of concern.  In 2002 , Elekta Instruments, bring together a team of experts started working to develop a new Gamma Knife System which can improve on existing models and has improved features. The group agreed on five critical features: best dosimetry performance, best radiation protection for patient and staff, unlimited cranial reach, full automation and outstanding patient and staff comfort. Leksell Gamma Knife perfexion was developed in 2006 malformations these criteria to a new platform and best performance till date in all accounts.