Gamma Knife Radiosurgery Has Found Its Commercial Replacement Cycle and Elekta Is Building the Next Generation

The Surgical Tool That Uses No Scalpel

Stereotactic radiosurgery delivers highly focused radiation dose to intracranial targets with the submillimetre geometric precision that the stereotactic frame or frameless image guidance system whose coordinate reference allows the radiation beams to converge at the treatment target from multiple non-parallel directions, concentrating dose at the intersection while sparing the brain tissue through which the individual beams pass. The Gamma Knife, whose design uses 192 or 201 cobalt-60 radioactive sources arranged in a hemispherical array that focus their gamma ray beams on a single point at the centre of the hemisphere, was the original stereotactic radiosurgery system and has accumulated over fifty years of clinical experience and outcome data that makes the Leksell Gamma Knife the most clinically validated stereotactic radiosurgery system for intracranial targets. Its clinical applications encompass acoustic neuromas, meningiomas, brain metastases, arteriovenous malformations, trigeminal neuralgia, and selected other intracranial conditions whose treatment by focused radiation achieves tumour growth arrest, vascular obliteration, or pain relief through the radiobiological effects of the high single-fraction dose that Gamma Knife delivers to the target.

The Gamma Knife radiosurgery market, valued at approximately $900 million in 2026 and growing at eight percent annually toward $1.5 billion by 2033, encompasses the capital equipment market for new system installations, the replacement equipment market for the clinical sites whose installed Gamma Knife systems have reached the end of their operational life or have been superseded by newer technology generations, and the cobalt source replacement market whose scheduled reloading of the radioactive sources whose half-life of five and a quarter years requires periodic source replacement to maintain treatment dose rate. The replacement cycle that Elekta is now entering, as the large number of Leksell Gamma Knife C and 4C units installed in the 2000s and early 2010s reach the age at which their technology generation and mechanical condition create the upgrade incentive, is the commercial opportunity that the Gamma Knife market's installed base of approximately four hundred systems in the United States and eight hundred globally is generating.

Elekta Leksell Icon and the Frameless Treatment Revolution

Elekta's Leksell Gamma Knife Icon system, the current generation of Gamma Knife technology, incorporates the frameless immobilisation and real-time motion management capability that the original Gamma Knife's requirement for rigid frame attachment had prevented. The original Gamma Knife's stereotactic accuracy depended on the rigid metal frame bolted to the patient's skull under local anaesthesia, whose fixed coordinate system allowed the treatment plan to be registered to the frame's known geometry with the submillimetre accuracy that single-fraction radiosurgery requires. The frame provided the accuracy but at the cost of the patient experience of frame placement and the logistical constraint of completing the imaging, planning, and treatment within a single anaesthetic or sedation session. The Icon's high-definition motion management system using an infrared camera that tracks facial reference points on a thermoplastic mask whose customed fit allows frameless immobilisation creates the submillimetre accuracy of frame-based treatment without the frame's invasiveness, enabling the hypofractionated treatment courses of two to five fractions that frameless immobilisation facilitates and that the radiobiology of certain target types favours over single-fraction treatment.

Accuray's CyberKnife, the competing stereotactic radiosurgery system that uses a robotic arm-mounted linear accelerator to deliver radiation from multiple non-coplanar angles, creates the extracranial stereotactic radiosurgery capability that the Gamma Knife's cobalt source geometry constrains to the intracranial space. CyberKnife's M6 and S7 systems, whose robotic arm freedom allows treatment of spinal, lung, liver, and other extracranial sites in addition to intracranial targets, serve the stereotactic body radiotherapy market whose clinical applications extend beyond the Gamma Knife's intracranial focus. The clinical overlap between the two systems is greatest in brain metastases, whose increasing prevalence as systemic cancer treatment improves survival and creates the need for intracranial disease management, and whose small target size and high dose requirement per fraction align equally well with both the Gamma Knife's cobalt geometry and the CyberKnife's linac geometry.

The Brain Metastases Market Expansion

Brain metastases are the primary growth driver for the Gamma Knife and stereotactic radiosurgery market, whose increasing treatment volume reflects both the rising prevalence of patients with brain metastases as systemic cancer treatments improve survival while intracranial control remains a clinical challenge and the clinical evidence accumulation that supports treating a larger number of brain metastases with stereotactic radiosurgery rather than whole-brain radiation therapy whose cognitive side effects at standard palliative doses create the quality-of-life deficit that radiosurgery's focused treatment avoids. Clinical trials demonstrating that treating four to fifteen brain metastases with stereotactic radiosurgery achieves local control rates equivalent to treating one to three metastases, while whole-brain radiation's cognitive effects are proportional to the dose volume rather than the number of targets treated, have expanded the clinical indication for Gamma Knife treatment into the multiple metastases patient population whose prevalence substantially exceeds the single or oligometastatic population that earlier clinical practice patterns had treated with radiosurgery.

Top 10 Companies in Stereotactic Radiosurgery Systems Globally

1. Elekta (Leksell Gamma Knife): Swedish radiosurgery company with Leksell Gamma Knife Icon and the fifty-year clinical legacy of Gamma Knife radiosurgery; its frameless immobilisation capability and its installed base of 800 global systems entering their replacement cycle create the dominant stereotactic radiosurgery company whose cobalt-based system defines the clinical gold standard for intracranial radiosurgery.
2. Accuray (CyberKnife): US radiosurgery company with CyberKnife M6 and S7 robotic radiosurgery systems for intracranial and extracranial applications; its robotic arm flexibility enabling extracranial stereotactic body radiotherapy and its Radixact TomoTherapy platform create the competing commercial radiosurgery system whose extracranial capability differentiates it from the intracranial-focused Gamma Knife.
3. Varian Medical Systems (Siemens Healthineers): US radiation therapy company with Edge radiosurgery linear accelerator and HyperArc radiosurgery treatment delivery software; its linac-based radiosurgery capability that delivers single-isocenter multiple target treatment and its installed base of radiation therapy linacs create the radiation oncology equipment company's radiosurgery commercial position.
4. BrainLab: German medical technology company with Radiosurgery software and image guidance systems for stereotactic radiosurgery on multiple linac platforms; its ExacTrac Dynamic frameless positioning and its treatment planning software create the software and guidance technology company whose products enable radiosurgery on conventional linacs rather than dedicated radiosurgery systems.
5. ZEISS (Intrabeam): German optics and medical technology company with Intrabeam intraoperative radiotherapy system for localised brain tumour treatment; its miniaturised X-ray source that delivers radiation at the surgical cavity immediately following tumour resection creates the intraoperative radiosurgery application that complements external beam radiosurgery for specific surgical contexts.
6. RefleXion Medical: US radiotherapy company with biology-guided radiotherapy whose PET-CT integration allows real-time tumour-signal guidance of treatment delivery; its unique tumour-guided radiation delivery and its clinical programme for lung and other solid tumours create the novel radiotherapy modality whose biology guidance principle differs from the geometric precision of conventional stereotactic radiosurgery.
7. IBA (Ion Beam Applications): Belgian particle therapy company with proton therapy systems that deliver stereotactic proton radiosurgery for intracranial and extracranial targets; its proton beam's physical Bragg peak dose deposition creating the dose conformality advantage for selected intracranial targets where the proton beam's depth-dose distribution allows dose delivery to deep targets with lower normal tissue dose than photon-based radiosurgery.
8. Mevion Medical Systems: US compact proton therapy company with single-room proton systems capable of stereotactic proton radiosurgery; its compact synchrocyclotron and its clinical deployment in community cancer centres create the accessible proton radiosurgery platform that challenges both cobalt-based and linac-based stereotactic radiosurgery in the brain tumour market.
9. ViewRay (MRIdian): US MR-guided radiotherapy company with MRIdian Linac for real-time MRI-guided radiation delivery; its real-time soft tissue visualisation during treatment delivery creating the adaptive radiotherapy capability for moving targets and its body radiosurgery applications create the MR-guided radiation therapy alternative for the extracranial stereotactic radiosurgery market.
10. Best Theratronics: Canadian radiation therapy company with cobalt-60 radiotherapy systems for developing world markets; its TeleCobalt machines and its cobalt source supply services create the radiotherapy equipment company whose cobalt technology serves markets where the capital and maintenance costs of linear accelerators prevent access to modern radiotherapy and whose cobalt expertise includes the source reload services that Gamma Knife operators require for scheduled maintenance.