The Gamma Knife radiosurgery system stirred a lot of discussion at the recent American Association of Neurological Surgeons (AANS) Annual Meeting, which took place in Los Angeles. The system, manufactured by the Swedish company Elekta, figured in more than a dozen abstracts at the conference.
To learn more about the Gamma Knife, Surgical Products interviewed Shyamal C. Bir, MD, PhD, postdoctoral fellow, one of the researchers who presented at the AANS Annual Meeting.
What can you tell us about the recent study you conducted involving the Gamma Knife radiosurgery system?
We evaluated 90 patients with intracranial meningiomas who underwent either microsurgery (n=31) or Gamma Knife radiosurgery (GKRS, n=59) and found that GKRS had a significantly higher rate of tumor control compared with surgery (95% vs. 81%, p=0.003) and a significantly longer period of recurrence-free survival (94 months vs. 84 months, p=0.04).
For microsurgery patients who had Simpson grade I resection, which is a complete removal of the meningioma and resection of the underlying bone and associated tissue, median recurrence-free survival was similar to that of patients in the GKRS group.
While the treatment of meningiomas should always be tailored to address each patient’s comorbidities and needs, our results demonstrate that GKRS can produce positive outcomes in this indication.
What will surgeons find unique and innovative about the Gamma Knife system?
Gamma Knife is a unique system with a frame that allows the physician to target a treatment area in brain with pinpoint accuracy. This is expected to enable unmatched efficiency and outstanding results.
Gamma Knife procedures are non-invasive and performed in a single session without general anesthesia. It delivers the highest level of physician and patient satisfaction because patients benefit from fast, painless treatment and a shorter hospital stay.
In addition to its superior clinical efficiency, Gamma Knife is also a very cost effective alternative to open brain surgery. It allows for more effective treatment of smaller lesions of the brain with fewer complications.
For older patients with medical comorbidities that make brain surgery too risky, GKRS can be a life-saving procedure.
Are there adjustments surgeons will need to make if they move toward radiosurgery approaches?
Physicians need to counsel their patients properly regarding the risks and benefits of GKRS. Immediate side effects, including swelling surrounding the tumor, are common, and these side effects may mimic the symptoms of the tumor. There may also be long-term effects, such as cyst formation, damage to soft tissue, and neuropathy.
Scientists and physicians need to work together to reduce these complications so that we can provide patients with optimal treatment outcomes. Another important factor is that Gamma Knife therapy requires coordination and teamwork among a physicist, a neuro-oncologist, and a neurosurgeon, which is not the case for more traditional surgical procedures.
Anything else you’d like to add?
The results of our study demonstrate that GKRS results in higher rates of tumor control and longer periods of recurrence free survival compared with microsurgery, and suggest that GKRS should be considered as an important treatment option for patients with intracranial meningiomas.