The Evolution of Gamma Knife Technology (Podcast)

Since the inception of Gamma Knife® technology more than 55 years ago, this stereotactic radiosurgery platform designed to treat brain tumors has never stopped evolving.

“In its current iteration, Gamma Knife uses 192 beams of radiation, all focused on a single point,” says Samuel Chao, MD, Associate Director of the Gamma Knife Center at Cleveland Clinic. “We aim to direct these beams to the tumor and cover the entire tumor with focused, high-intensity radiation while sparing the surrounding brain tissue as best as we can.”

In the latest episode of Cleveland Clinic’s Cancer Advances podcast, Dr. Chao talks about advances in Gamma Knife radiosurgery. He delves into:

• Use of Gamma Knife to treat brain metastases, malignant tumors and benign tumors, as well as functional and vascular disorders
• Differences between Gamma Knife, stereotactic body radiation therapy and proton therapy
• Advantages and limitations of Gamma Knife treatment
• Developments on the horizon to make the technology more effective

Click the podcast player above to listen to the 20-minute episode now, or read on for a short edited excerpt. Check out more Cancer Advances episodes at clevelandclinic.org/podcasts/cancer-advances or wherever you get your podcasts.

Excerpt from the podcast

Podcast host Dale Shepard, MD, PhD: It’s hard to count the number of times one goes on hospital service and someone comes in with a brain metastasis, after which both radiation oncology and neurosurgery are consulted. What are the respective types of situations where radiation is clearly better and where surgery is clearly better?

Dr. Chao: Oftentimes we think about radiosurgery as our No. 1 modality for treating brain metastases because it’s noninvasive and it’s really easy to do. It gets patients back on their feet faster. They can go on to systemic therapies much more quickly than if we do something invasive like a craniotomy. That being said, craniotomy to take out tumor still has its role in terms of the management of brain metastases.

Surgery may be beneficial for patients who are very symptomatic and for tumors that are extremely large — impinging heavily on the brain and causing a lot of swelling in the surrounding brain tissue. So when we go and see a patient on the hospital floor together with neurosurgery, that allows us to chat and decide on what’s the best option for the patient.

One thing we have started doing over the past several years is to even consider doing Gamma Knife radiosurgery before doing surgery — what we call neoadjuvant radiosurgery. This can make things a lot more straightforward and make treatment happen a lot more quickly. The neurosurgeons don’t have to wait for us to do radiation to clean up the resection cavity. This approach makes the radiation much tighter. It prevents development of leptomeningeal disease and reduces the risk of radiation necrosis. For many of the patients in the scenario you describe, even those in whom we decide we want to do surgery, sometimes we can strategize by doing some radiosurgery in advance to essentially “sterilize” the tumor.