The Technology

Benefits for the Patients
The radiation unit of the Leksell Gamma Knife contains 201 cobalt-60 sources secured within a hemispherical body. The radiation beams are collimated and converge precisely to the common focal point at the center of the radiation unit. The radiation unit is heavily shielded in order to provide radiation protection for the patient and hospital staff. During treatment there are no moving parts within the Leksell Gamma Knife, and therefore safety, stability, reliability and precision are inherent features.

The Leksell Gamma Knife is provided with four helmets with collimators of different sizes: 4mm, 8mm, 14mm and 18mm. Helmets may be used individually for a single spherical lesion, such as a 4mm for a functional target. More commonly, however, multiple isocenter treatment plans are delivered by changing the helmet and combining various sized isocenters. This yields a combined dose that can be accurately and reliably tailored to conform to even the most complex lesions. This unique ability of Gamma Knife Surgery has resulted in multiple isocenter treatment plans being the norm, and an average of over six isocenters per treatment plan being reported by the Leksell Gamma Knife users.

The operating table consists of a couch support and a sliding cradle with helmet support. The movements of the sliding cradle into the treatment position and the opening and closing shielding doors are performed by electric motors. The control panel, from which the Leksell Gamma Knife is operated and the procedure supervised, is located in an area adjacent to the treatment room. The patient can be monitored on a closed-circuit TV, and an intercom system is used for communication between staff and patient.

The treatment planning system is an integrated part of the Leksell Gamma Knife and is usually located adjacent to the treatment room. Complex 3-D treatment plans based on CT, MR, and angiography are routinely accomplished using the world renowned Leksell GammaPlan.