Leksell Gamma Knife® (Elekta Esprit); Leksell Gamma Knife® (Icon™); Leksell Gamma Knife® (Perfexion™)

The Leksell Gamma Knife is a teletherapy device that delivers stereotactic irradiation (focused radiation) to head structures for treating tumors, vascular malformations, and functional disorders. It uses 192 radiation sources to target lesions ranging from millimeters to several centimeters, including metastatic tumors, glioblastomas, trigeminal neuralgia, essential tremor, and certain epilepsy types.

The subject device replaces obsolete hardware components (ECU, kV-generator, HDMM camera) with updated versions and updates the control system software from version 11.5 to 11.6. The fundamental design remains unchanged: 192 radiation sources, Windows 10 operating system, and identical user interfaces, surveillance systems, fixation methods, and imaging modalities across three models (Esprit, Icon, Perfexion).

IEC 60601-1 (general safety), IEC 60601-1-2, IEC 60601-1-3, IEC 60601-1-6, IEC 60601-1-8, IEC 60601-2-11, IEC 60601-2-28, IEC 60601-2-68, IEC 62304, ISO 10993 biocompatibility series (10993-1, -5, -10, -18, -23), and IEC 62366-1 (usability).

The intended use is identical to the predicate device (stereotactic irradiation of head structures). Component replacements (ECU, kV-generator, HDMM camera) are functional substitutions that do not alter clinical workflow, safety, functionality, or performance. New indications for epilepsy fall within the predicate's intended use scope, and radiation treatment for underlying structural causes was already on-label. Verification and validation testing confirms conformance to safety standards and that the device functions as intended with the same benefit-risk profile as the predicate.