Neurological Indications for Stereotactic Radiosurgery

Podcast Transcript

Neuro Pathways Podcast Series

Release Date: December 1, 2025
Expiration Date: November 30, 2026

Estimated Time of Completion:  30 minutes

Neurological Indications for Stereotactic Radiosurgery
Lilyana Angelov, MD

Description
Each podcast in the Neurological Institute series provides a brief, review of management strategies related to the topic.

Learning Objectives

• Review up to date and clinically pertinent topics related to neurological disease
• Discuss advances in the field of neurological diseases
• Describe options for the treatment and care of various neurological disease

Target Audience

Physicians and Advanced Practice providers in Family Practice, Internal Medicine & Subspecialties, Neurology, Nursing, Pediatrics, Psychology/Psychiatry, Radiology as well as Professors, Researchers, and Students.

ACCREDITATION

In support of improving patient care, Cleveland Clinic Center for Continuing Education is jointly accredited by the Accreditation Council for Continuing Medical Education (ACCME), the Accreditation Council for Pharmacy Education (ACPE), and the American Nurses Credentialing Center (ANCC), to provide continuing education for the healthcare team.

CREDIT DESIGNATION

• American Medical Association (AMA)
  Cleveland Clinic Center for Continuing Education designates this enduring material for a maximum of 0.50 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
  
  Participants claiming CME credit from this activity may submit the credit hours to the American Osteopathic Association for Category 2 credit.

• American Nurses Credentialing Center (ANCC)
  Cleveland Clinic Center for Continuing Education designates this enduring material for a maximum of 0.50 ANCC contact hours.

• Certificate of Participation
  A certificate of participation will be provided to other health care professionals for requesting credits in accordance with their professional boards and/or associations.

• American Board of Surgery (ABS)
  Successful completion of this CME activity enables the learner to earn credit toward the CME requirements of the American Board of Surgery’s Continuous Certification program. It is the CME activity provider's responsibility to submit learner completion information to ACCME for the purpose of granting ABS credit.
  
  Credit will be reported within 30 days of claiming credit.

Podcast Series Director

Andreas Alexopoulos, MD, MPH
Epilepsy Center

Additional Planner/Reviewer

Cindy Willis, DNP

Faculty

Lilyanan Angelov, MD
Brain Tumor and Neuro-Oncology Center

Host

Glen Stevens, DO, PhD
Cleveland Clinic Brain Tumor and Neuro-Oncology Center

Agenda

Neurological Indications for Stereotactic Radiosurgery
Lilyana Angelov, MD

Disclosures

In accordance with the Standards for Integrity and Independence issued by the Accreditation Council for Continuing Medical Education (ACCME), The Cleveland Clinic Center for Continuing Education mitigates all relevant conflicts of interest to ensure CME activities are free of commercial bias.

The following faculty have indicated that they may have a relationship, which in the context of their presentation(s), could be perceived as a potential conflict of interest:

Glen Stevens, DO, PhD

DynaMed Consulting

All other individuals have indicated no relationship which, in the context of their involvement, could be perceived as a potential conflict of interest.

CME Disclaimer

The information in this educational activity is provided for general medical education purposes only and is not meant to substitute for the independent medical judgment of a physician relative to diagnostic and treatment options of a specific patient's medical condition. The viewpoints expressed in this CME activity are those of the authors/faculty. They do not represent an endorsement by The Cleveland Clinic Foundation. In no event will The Cleveland Clinic Foundation be liable for any decision made or action taken in reliance upon the information provided through this CME activity.

HOW TO OBTAIN AMA PRA Category 1 Credits™, ANCC Contact Hours, OR CERTIFICATE OF PARTICIPATION:

Go to: Neuro Pathways Podcast December 1, 2025 to log into myCME and begin the activity evaluation and print your certificate If you need assistance, contact the CME office at myCME@ccf.org.

Copyright ©2025 The Cleveland Clinic Foundation. All Rights Reserved.

Introduction: Neuropathways, a Cleveland Clinic podcast exploring the latest research discoveries and clinical advances in the fields of neurology, neurosurgery, neuro rehab, and psychiatry.

Glen Stevens, DO, PhD: Stereotactic radiosurgery is changing the way we treat brain and spine conditions, offering precise targeted care for complex neurologic cases. In this episode, we'll explore when and why radiosurgery is used, highlight advances in both brain and spine treatments, and discuss how collaboration and innovation are driving better outcomes for patients of all ages.

I'm your host Glenn Stevens, neurologist neuro oncologist in Cleveland Clinic's Neurological Institute. And joining me for today's conversation is Dr. Lilyana Angelov. Dr. Angelov is a neurosurgeon and director of Cleveland Clinic's Gamma Knife Center. Lily, welcome to Neural Pathways.

Lilyana Angelov, MD: Thank you.

Glen Stevens, DO, PhD: So, Lily, I'm very excited that you're here today because we're fellow Canadians. I don't always get to have a Canadian that's here, but it's always great when we do. So thanks for joining me today.

Lilyana Angelov, MD: Thank you.

Glen Stevens, DO, PhD: So, let's start by having you introduce yourself to our listeners. Where did you train and what do you do here at the Cleveland Clinic?

Lilyana Angelov, MD: I originally trained in Toronto for medical school and for my neurosurgical training. At that time we didn't have gamma knife technology or radiosurgery technology available, so I came here to the Cleveland Clinic to do a fellowship and I have been here for 23 years. Where do the years go?

Glen Stevens, DO, PhD: For our listeners unfamiliar with the technology, tell us what stereotactic radiosurgery is and how does it differ from what people would think of as traditional radiation?

Lilyana Angelov, MD: Stereotactic radiosurgery is precision targeted radiation to a finite number of targets. The analogy that I tend to use when I describe the treatment is that it's like a glove fitting a hand. It's not even a mitten because it has to target the areas that we're interested in targeting and spare. For example, the way a glove would do the interspaces between and spare the normal brain in this setting to make sure that we protect the normal tissue and yet be able to provide high dose radiation to kill off the abnormality that we are targeting with the treatment. It is called stereotactic radiosurgery because much like surgery, it is delivered in a single or a finite number of sessions. The analogy that I use for some of the tumor treatments is that it's like plucking a few dandelions. You can't pluck a whole field of dandelions. Conventional radiation is like spreading the weed kill. It is diffuse therapy that is not so targeted precision wise, but gives big field treatments over multiple sessions.

Glen Stevens, DO, PhD: So, there's clearly different platforms that can deliver radiosurgery. And talk a little bit about some of the platforms that are available that people may be familiar with.

Lilyana Angelov, MD: So, the platform that we have been using here for many years for brain treatments is gamma knife radiosurgery, and the machine itself looks like a giant hairdryer, for example at a lady salon. It is a system that is specifically designed to treat brain indications and it is the most precise currently available in the field to do that precision targeting. Some of the other platforms that we use in terms of body radiation, be it for the spine or other indications, are technologies that are called edge, which is a precision delivery system through a linear accelerator delivery, which is a little bit different than the system that we use in brain for gamma knife treatment.

Glen Stevens, DO, PhD: Yeah, I think it's just important that people understand that gamma knife is not for the spine,

Lilyana Angelov, MD: Correct? It's not for the spine and nor is it a knife.

Glen Stevens, DO, PhD: Yes. Which confuses a lot of people, right?

Lilyana Angelov, MD: Correct.

Glen Stevens, DO, PhD: How long have we had a gamma knife here?

Lilyana Angelov, MD: We have had a gamma knife since 1997. We were one of the pioneers in the US and worldwide in doing this treatment and we have had several iterations and we currently have two machines where one of four places worldwide that have two gamma knife machines in side by side vaults. And we have been doing treatment with the latest most current gamma knife for several years now.

Glen Stevens, DO, PhD: And my understanding is that historically patients all had to be treated with a head frame and then there's been development and people can now potentially be treated with a mask as well. Correct. Can you discuss?

Lilyana Angelov, MD: That with the head frame? It is minimally invasive. We needed to have a frame of reference to do precision targeting and so the frame was the traditional gamma knife treatment. Since then, as technology has developed, we have moved from minimally invasive to non-invasive treatments for many indications. And now here at the Cleveland Clinic there is probably about 70% of our patients that are being treated completely noninvasively for their management of brain disorders that we're treating.

Glen Stevens, DO, PhD: And for our listeners, tell them what's the function of the frame or the mask, why does it have to be on?

Lilyana Angelov, MD: So, it has to be on because you need to do precision targeting. In order to have precision, you can't have motion in your target. And so we dock the patient to a long couch that looks like a hospital bed for example, and this frame or mask is attached to our treatment couch in order to deliver that targeting within one to two millimeters of the desired target. So very highly targeted precision because the patient is immobilized in terms of the target.

Glen Stevens, DO, PhD: Why might you decide to treat with a frame or a mask?

Lilyana Angelov, MD: The indications are very specific. For example, in patients that are being treated for trigeminal neuralgia in those settings, because the trigeminal nerve is basically several hair strands and thickness, you would like the immobilizing device through the scalp and attached directly to the patient rather than molded onto the patient's face to make the tracking more seamless.

Glen Stevens, DO, PhD: So, I appreciate your bringing that up. So we'll just move into that area. What are the common neurologic disorders that we treat with gamma knife and we'll get to the spine. I know you do a lot of spine radiosurgery.

Lilyana Angelov, MD: Alright, so the common brain indications that we treat, the vast majority of indications that we treat is metastatic disease. This is cancer that has started in a remote part of the body that then takes root and grows in the brain. And the analogy that I use is that there is like a puff ball on a dandelion that's gone to a puff ball and then the seedlings float away and take root in favorable soil. In many systemic cancers, the favorable soil ends up being the brain and so many of our patients are referred through our Taussig colleagues at the cancer center where they now have their lung cancer or their melanoma take root in the brain, and we do precision targeting for that. Other indications are indications that are related to facial pain. There are indications related to vascular abnormalities. For example, arterial venous malformations, which is like a tangle of vessels, often deep, often surgically treacherous to deal with that can be precision targeted in a noninvasive way. These are some of the other indications. Benign disease like benign tumors affecting the hearing nerve and balance centers, meningiomas, which are benign tumors in most instances arising off the lining of the brain. There is a whole myriad of benign and metastatic disease. We are moving forward in terms of our better understanding of when to apply it for certain primary brain tumors, including occasionally the most malignant of the primary brain tumors, which is glioblastomas.

Glen Stevens, DO, PhD: So, like a lot of things, it takes a village.

Lilyana Angelov, MD: It does.

Glen Stevens, DO, PhD: And it's a collaboration between typically a surgeon, a radiation oncologist and a medical physicist talk about the roles of these people.

Lilyana Angelov, MD: Exactly. It takes a village and actually that's one of the huge privileges of being here at the Cleveland Clinic because we are very multidisciplinary focused and our patient care arises from that even before patients are referred for gamma knife. Many times we've discussed the patient care at brain tumor board where we are a multidisciplinary group that comes together and optimizes the best treatment for patients if a patient is appropriate for gamma knife treatment. The way we manage our patients here is that the neurosurgeon is responsible if it's going to be a frame based case for applying the frame to the patient, then there is the identification of the target. I always say that when I work with radiation oncology that I, because I deal with the anatomy, I'm the spotter and they deliver the radiation to that spot because they're the sharpshooter and this is why we work together. The physicist is the one who confirms that the delivery that we have requested and planned is actually deliverable. All three of us have to sign the plan and nursing and our therapist, radiation therapists are an essential component of patient comfort, patient safety and workflow in the entire center. So it really does take a village. There is over 40 of us that are affiliated with our Cleveland Clinic Gamma Knife Center, and it's a huge privilege to work with such an incredible group.

Glen Stevens, DO, PhD: And how many cases per year are we doing here?

Lilyana Angelov, MD: We are doing nearly a thousand and we are the busiest gamma knife center in the Americas in North and South America.

Glen Stevens, DO, PhD: Excellent. It's always difficult to answer this question because there's so many variables, but with metastasis in your treating response rates?

Lilyana Angelov, MD: Our response rates are anywhere between 85 to 90% routinely and that is agnostic to the pathology. So it could be, while conventional radiation bumps up against some of the barriers of more radio resistant tumors, we do not see that so much in radiosurgery. The dosing tends to be ablative, whether it is more stubborn to radiation treatment or not so stubborn to conventional treatment, we have equally effective outcomes with radiosurgery.

Glen Stevens, DO, PhD: So, what's the key difference between treating radiosurgery in the brain versus the spine? And I know you do both of them, but go through the spine radiosurgery.

Lilyana Angelov, MD: So, spine radiosurgery, the key difference in my mind is that the brain radiosurgery, especially in malignant metastasis for example, the typical metastasis in the brain is in the brain tissue itself. The typical metastasis that we see that affects the spine affects the spinal column rather than the spinal cord. And the spinal column protects the spinal cord the way the skull protects the brain, but there is a higher likelihood in terms of spine disease to be involving the bone so that the toxicity of that treatment is related to making sure you give a high enough dose to the bone and having that dose drop off precipitously before it gets to the spinal cord and the spinal cord can be kind of thin. It's about the size of two fingers breaths, if you will, so that all those neurons from the brain channel into a very small off ramp from the big highway. And so the tolerance of the cord is in many ways much lower than even brain. And so that toxicity has to be carefully measured and also immobilization techniques are very different. So those are among the more relevant areas. The other thing is sometimes spinal tumors tend to be much larger than what we encounter in brain. And so efficacy, it becomes very essential to evaluate is this focal and is this appropriate for treatment?

Glen Stevens, DO, PhD: And very commonly you can do imaging treatment with a brain lesion in the same day. Can you do the same with spine or it's a little more complex, you need to do the spine imaging a few days before?

Lilyana Angelov, MD: That's correct. Actually, I'm glad you pointed that out. Much of the spine planning is done over several days because there has to be a dry run through in terms of the immobilization, the planning platform is different, the edge system compared to the gamma knife. And so yes, there needs to be a lag time. The analogy for example, that I use is, I'm an analogy girl obviously, but one is like driving a Ferrari and the other one's like driving a Lamborghini, you get there, they're highly effective, excellent treatments, but each of the vehicles has its own requirements, its own idiosyncrasies, et cetera. And so they require a different subset of skills and a different planning.

Glen Stevens, DO, PhD: So, Lily, I know this probably doesn't happen that often in the brain, but the concept of separation surgery, tell us what that is and why it's important in the spine.

Lilyana Angelov, MD: So that is a terminology actually that we developed here at Cleveland Clinic and separation surgery is that we would, as kind of alluded to earlier, we really would like to give very high dose to the tumor but have this precision radiation drop off before it gets to that much smaller spinal cord that lives behind it. Sometimes the tumor abuts or hits right up against the cord and you cannot deliver a sufficiently high dose in order to achieve that. So separation surgery is a strategy where you could do less invasive, often minimally invasive surgical procedure to not eradicate the entire tumor, but to make a distance the back of the bone and the spinal cord with a more minimally invasive procedure. So once we started doing this, and this has been something that's been embraced in the spinal oncology world, patients that used to have major thoracotomies that would be in the ICU for weeks and months on end because of such a large procedure, surgically can have minimally invasive procedure, minimum blood loss, stabilization, and then the ultimate treatment is the spine radiosurgery with the surgical piece being the adjunct or neoadjuvant step to help deliver the highly effective dose, which is also 85 to 90% control of tumors.

Glen Stevens, DO, PhD: So, this is a question you could probably spend the whole day answering, but let's say I come see you, I've got lung cancer, I have six metastasis. How do you decide should I have a whole brain radiation, should I have radiosurgery? How do you decide?

Lilyana Angelov, MD: So here there are a number of factors, and yes, you are correct to allude to the fact that it is multifactorial. Often it is related to the number of brain lesions. Here at the Cleveland Clinic we tend to treat patients with multiple brain metastases because we have determined that the efficacy of the treatment is not so much related to number, but rather the need for control and how likely we are to achieve control so that it isn't that six metastasis immediately you go to more global treatment. Other things that are important is that neurocognitive issues become very important when we do this precision targeting where we spare normal brain with whole brain radiation, the entire brain sees a low level of radiation. As people age, their tolerance for a low level of radiation drops and therefore in more elderly patients, it is appropriate to try and defer or avoid whole brain radiation. If patients have many, many lesions, then it goes back to that dandelion approach that we were dealing with. If you've got six dandelions, you can eradicate them by plucking them out. If you have 60, then you need to spread weed kill in order to eradicate a large volume of disease.

Glen Stevens, DO, PhD: So, if I come see you for my six mets and you say you're a good candidate to do this radiosurgery, how long will it take me to get in to get treated?

Lilyana Angelov, MD: We actually at the Brain tumor center access any patients seeking care within 72 hours for metastatic disease. So we access our patients very quickly and typically most of us don't carry long waiting lists because there is a certain urgency based on size, location based on the need for other treatments to get the patient's. So many patients are treated the following week because in that situation it's scary not to know what's going on. It's scary to feel out of control and patients truthfully would like to be treated yesterday. And that's the driving force behind all of us who treat in the gamma knife center is to help access patients as quickly as is appropriate to do so safely. The other advantage that we have with radiosurgery is unlike surgery in terms of a treatment, patients typically do not have to stop their anticoagulation treatments. They can have low platelets from their chemotherapy or other systemic reasons for having low platelets and we can still move forward with their treatment without a meaningful delay or stopping other essential therapies.

Glen Stevens, DO, PhD: So, I know you're not a radiation oncologist, but same scenario, I've got prostate cancer now with bone mets to the spine, how do they decide? Do I just do conventional radiation or should I do SRS or is there an algorithm or?

Lilyana Angelov, MD: So yes, in fact there is and there is a lot of recent data out in terms of prostate cancer. Again, the primary fork in the road is essentially bulky disease or extensive disease versus what's called oligometastatic disease. And oligometastatic is five lesions, five metastatic lesions. Specifically in prostate. There's data that's about five years old or so that says that if we treat oligometastatic disease early with ablative therapy like radiosurgery, we almost turn back the clock to a low volume mets disease or to a pre metastatic state. So not only does it control the disease locally, but it prolongs survival. The data supports prolonged survival. So very often I am referred these patients with a low burden of spine disease that don't have pain but have this low burden in order to treat them and improve their overall survival. So it's been a really gratifying part of that. The other indications for treating spine disease is pain. So even if patients have diffused spine disease, if there is one area that is particularly symptomatic or that has extension that is coming very close to the cord, those patients are treated with focal therapy with the hopes that the systemic therapy can keep everything else kind of suppressed and allow them to continue their therapy without interruption.

Glen Stevens, DO, PhD: And outcomes for pain?

Lilyana Angelov, MD: Outcomes for pain, 85 to 90%

Glen Stevens, DO, PhD: Seems to be the common number.

Lilyana Angelov, MD: It is the common number, but truly we have prospectively evaluated pain outcomes. And it's such a gratifying practice where patients will often tell you, especially if they have metastasis in their thoracic spine, so they sit up in a recliner because extending lying down is a problem. And I've had many a patient tell me, Dr. Angelov, I have been sleeping in a recliner now for four weeks a week post-treatment. I was finally able to go back and sleep in my bed. And that not only helps with the pain, but their sense of quality and their feeling that life is significantly improved.

Glen Stevens, DO, PhD: So you've been involved in some interesting research in different ways of giving or altering the pattern of the radiosurgery. Talk a little bit about fractionated and staged gamma knife. What is that?

Lilyana Angelov, MD: So this is an area of active research as well. When there is a large lesion, one gamma knife treatment may sometimes not durably hold the tumor. So this is referring to brain and it refers to brain tumors that are two centimeters in larger in size. So that there is an approach where either you can give it for five consecutive days to give radiosurgery for five consecutive days in the hope to make this a dose dense delivery of the treatment. Or what we have pioneered here at the Cleveland Clinic is to do two staged radiosurgery so that you treat a patient in a given month and then they can get their systemic therapy in between. And very often these tumors even shrink after the first treatment so that when you deliver the second treatment a month later, it is a smaller lesion and it has a smaller area of normal brain tissue around it. So it improves toxicity, still makes the dose dense and can be given uninterrupted systemic treatments in the meantime. So it has changed the way we view things, changed how we understand this delivery, and we are part of a multi-institutional trial, us and a Japanese group that do very similar treatments and our control rates are 91% at one year and beyond doing stage treatment. So it's a very gratifying, highly effective treatment with very acceptable side effects for the treatment.

Glen Stevens, DO, PhD: Now we get into the very difficult to treat the role of gamma knife with glioblastoma.

Lilyana Angelov, MD: So, glioblastoma is the Trojan horse of the brain because the cells are very much like brain cells, they look like brain cells. So the brain doesn't wall them off. Unlike, for example, lung cancer that goes to the brain that can often be walled off so that the edge is a lot more diffuse than sometimes we perceive. Recently we have worked towards seeing if there is a nest of cells that are more aggressive, that have recurred in a background where everything else is well controlled, and if we can deliver high dose to that visible nest, we find that our control of the disease in given patients almost doubles as a second or third line therapy. Still frontline therapy is surgery, radiation, systemic chemotherapy. But as a second and third line therapy, we have moved the needle we think by capitalizing on these small pockets of cells that we can ablate with radiosurgical treatment.

Glen Stevens, DO, PhD: So, something that's a little easier to treat is, you had mentioned it earlier, the atrial venous malformations or the AVMs, and historically as a surgeon you would cut all these out or they'd coil them or glue them or those types of things. But it seems to me that it's moved almost exclusively for the most part to radiosurgery for these. Why is that and how are the outcomes?

Lilyana Angelov, MD: So, the outcomes have been very favorable. It used to, even in my old training days, radiosurgery used to be third and fourth line therapy, but still surgery. If it is on the surface, surgically reachable, then yes, many times these are considered surgical lesions. But the second line therapy is not coiling and gluing so much anymore, but actual radiosurgical treatment. So the control rates are high, it obviates the need for surgery. It starts controlling so that patients don't have hemorrhagic strokes related to this treatment. And we found how to better manage larger lesions by treating kind of like tiles one next to the other. So we can treat very large lesions with adjoining fields over several sessions and we can achieve excellent control so that we are starting very much to push the barrier. And since we've moved that practice as well from minimally invasive with frame to frameless, it has made all the difference in the repeat treatments in the younger patients in the need to use anesthesia for certain patients, et cetera. Because in the pediatric world, applying a frame can be challenging and many times these AVMs are things that happen in younger patients, young adults, pediatric patients, et cetera.

Glen Stevens, DO, PhD: Well, that's right. Where I was going was to pediatrics talk about pediatric use of radiosurgery. I assume spine not so much, but can happen?

Lilyana Angelov, MD: Yes, spine too.

Spine too, with the sarcomas, the Ewing sarcomas, we tend to see that quite a bit. We are the busiest pediatric radiosurgery center in the country. We even have the privilege of being referred some of our spine cases from predominantly children's hospitals like St. Jude's that send them specifically here to us for radiosurgical treatment. The philosophy of the treatment is the same, the needs of the patients are different. Many times we have to use anesthesia for immobilizing, even for getting MRI scans to do precision targeting for young patients requires anesthesia, et cetera. The outcomes have been incredibly gratifying and have allowed the patients much longer quality and quantity of life as we treat these pediatric patients. And we have not seen unexpected toxicities, which used to be one of the major challenges by employing conventional radiation in a growing child.

Glen Stevens, DO, PhD: So, speaking of toxicity, obviously there's very delicate structures in the brain and of concern is always the optic nerve, the brainstem, how do we control dosing to those structures?

Lilyana Angelov, MD: So again, a non-moving target is what allows us to control because we know where the radiation dose is dropping, falling, and so making sure that we have our dose constraints carefully planned, carefully confirmed is how we control to those structures. And therefore the immobilization is one of the tenets or the keys to providing safe effective treatment.

Glen Stevens, DO, PhD: So, when gamma knife specifically was developed, it was mostly for functional disorders. Now we treat so many mets, where's the field going? What's on the horizon? What do you want to treat? How are we going to help patients outside of tumor?

Lilyana Angelov, MD: So probably I can answer that better with what are the challenges in the field. When we think about, for example, what do we do with patients that are now living much longer because systemically we have more lines of therapy, their disease has responded, and as we succeed better to make cancer a chronic condition, something similar to diabetes for example, then things crop up that are delayed manifestations of having the disease for a long period of time. So where are we going in the field? Recently we have started to occasionally have to do repeat gamma knife treatments for patients, understanding what that means, what the dosing is that's appropriate to those targets, how do we best manage that is one of the things that we have to understand in terms of the field. We spoke about large brain metastasis and how to best deliver that. That's where the field is going. There is more and more questions and to try and spare the patient from undergoing surgical treatment understanding is this lesion changing because it is just a radiation effect or is this really tumor coming back? And what are the next steps to manage that? Is there technology that is appropriate? Do patients have to undergo surgery? There's many of those questions that we are on the edge of understanding, but I think that there's still a lot of work to be done.

Glen Stevens, DO, PhD: So final comments for our listeners, takeaway points.

Lilyana Angelov, MD: The technology is highly effective for CNS indications, both benign and malignant indications. The treatment is done outpatient, and so it's been one of the most gratifying practices to be able to treat our patients, to let them have prolonged quality and quantity with minimal to no side effects. The best thing that I can tell you is, for example, after both gamma knife or spine radiosurgery, I've had many a patient get off the table and say, bye, doc, I'm taking my wife to lunch.

Glen Stevens, DO, PhD: Well, listen, Lily, I'm glad you could join us today and help our listeners understand radiosurgery a little bit better and appreciate all the work you're doing in the field.

Lilyana Angelov, MD: Thank you.

Closing: This concludes this episode of Neuro Pathways. You can find additional podcast episodes on our website, clevelandclinic.org/neuropodcast, or subscribe to the podcast on iTunes, Google Play, Spotify, or wherever you get your podcasts. And don't forget, you can access real-time updates from experts in Cleveland Clinic's Neurological Institute on our Consult QD website. That's @CleClinicMD, all one word. And thank you for listening.