Frameless Gamma Knife Radiosurgery with Leksell ICON: Initial Experience

Gamma knife radiosurgery saw the light of the day when the Swedish physician Lars Leksell postulated the salient first principles of stereotactic radiosurgery. Prior to being realized in its new `avatar' The ICON, Leksell Gamma Knife (LGK) Perfexion has been the most practiced model and is still in practice in most of the centers in India. The Gamma Knife ICON (the sixth generation model) utilizes the concept of the Cone-Beam Computed Tomography (CBCT) module, thus allowing non-invasive immobilization of the skull employing frameless treatments without jeopardizing accuracy to sub-millimeters. The LGK ICON however has the same stereotactic delivery and patient positioning system as Perfexion and mesmerizes the care givers with the added technically sound feature of the CBCT imaging arm, that is, CBCT and an intra-fraction motion management system. The experience with ICON on both the sub-sets of patients has been intriguing and awe-inspiring. Despite its challenges of being detected with significant intra-fraction errors, we realized that the non-invasive thermoplastic mask fixation system has its own set of specific characteristics: fairly simple dosimetry; short radiation delivery times; and calm, composed, co-operative patients. We have been successful in conducting frameless gamma knife surgeries in similar to 25% of patients planned for gamma knife surgery. We look forward to witness this avant-garde pioneering scientific automation being practiced in a higher number of patients.

Automated summary

Gamma knife radiosurgery was developed based on the principles of stereotactic radiosurgery proposed by Swedish physician Lars Leksell. The Perfexion model has been widely used in India but has now been replaced with the newer ICON model, which incorporates Cone-Beam Computed Tomography (CBCT) for non-invasive and accurate skull immobilization. Despite some challenges, the use of the ICON model has been successful in frameless gamma knife surgeries in around 25% of planned patients. Rating: 8/10.