Intermountain Health Oncologist, Grant Hunter, MD and Intermountain Health doctor, Michael Cutler, MD talk about a cancer treatment that is now being used to treat heart problems.
Interview conducted by Ivanhoe Broadcast News in 2023.
Let’s talk about this procedure that is typically used on cancer patients. How does it work?
Hunter: Yeah. In general, the procedure of stereotactic body radiotherapy and it’s used, there’s several different acronyms that it goes by SBRT was one of the first describing stereotactic delivery of focused radiation. High dose focused radiation initially pioneered to treat lung cancer, small lung tumors, or for patients that were inoperable with lung cancer. It was found to be a very safe and a very effective way of delivering high dose focused radiation. Over the years that has been used to treat tumors in bone or in the liver. This particular procedure is using that same idea, delivering high dose, very focused radiation to the heart to ablate or stop an abnormal arrhythmia called ventricular tachycardia.
Do you know how it was discovered?
Hunter: Sure, ventricular tachycardia, and Dr. Cutler will be even better to talk about that, but ventricular tachycardia is a potentially fatal arrhythmia that is treated by cardiologists with the standard of care of ablation and different techniques. But there are some patients that those techniques don’t work or they still have refractory ventricular tachycardia. And those are the patients that we’re really targeting with this procedure, this modality. So if they’ve had an ablation by a cardiologist and still have break arrhythmias, breakthrough tachycardia, those are the ones that we can try and target for this stereotactic radiation ablation of their tachycardia.
How big is this?
Hunter: So it’s used by a handful of centers in the country. We’ve done it in the state of Utah a couple of times. We were the first to pioneer it in the state of Utah here at Intermountain and a handful of other centers in the country are treating patients with this arrhythmia in this way.
How about in just the grand schemes things also how big is the discovery?
Hunter: Yeah. I think it’s a great option for patients who have this particular problem. Clearly the standard treatment for this will remain the standard treatment. But for those where the standard treatment, regular ablation fails, this is showing to be a very good option. The handful of patients we’ve treated at Intermountain have done very well. The reported literature from the other places in the country that have done it is very promising. So we’re happy to be able to offer it and one of the reasons it’s been a desirable option is that it’s an outpatient procedure. It’s a little anticlimactic after having a significant medical history and significant cardiac history for the patient to be able to come into the clinic, lay down on a table, be treated in a half an hour, and be able to get up and go home is really a great option for them.
What are the side effects?
Hunter: So the short term side effects of this are generally very mild as well. That’s one of the other really favorable points of this procedure, is that they tolerate it really well. In the short term, they might have a little bit of fatigue and maybe a little bit of chest wall pain, sometimes due to inflammation from the treatment itself. But we really haven’t seen significant short term injury to the heart or to the patient. It’s been amazing how few short term side effects there are, in the long term, obviously the most favorable outcome we’ve been looking for is to have the arrhythmia or this tachycardia go away or reduce the number and that’s what we’ve seen thankfully. Long term, greater than five or 10 years of follow up we just don’t have that data yet so that does highlight that it is new. There’s ongoing research throughout the country is breaking medical procedure that’s very promising. But it does also highlight the fact that continued follow up with cardiology to continue to learn will be important as we carry on with this new treatment.
Do you know what it means for the quality of life for the people who do go through this?
Hunter: Yeah, that’s a great question. The patients that we’ve treated here at Intermountain have had a dramatic improvement in their quality of life. A couple of them come to mind. One has progressed to be able to do more and more exercises, be more and more active at home, that he just was not able to. One of the points of this treatment is that patients really don’t have a lot of other options. By the time they’re having this problem refractory ventricular tachycardia, they’ve been through all the standard treatments and they don’t have a lot of options and they’re in a bad spot. It can certainly be life threatening and so to be able to offer something to them that has had low side effects, low toxicity, and a pretty darn good and pretty promising long term outcome has been really good. For the patients we’ve treated they’ve been very pleasantly surprised how well they’ve tolerated it and how well they’ve done.
When you do discover how some procedures also work for other patients, do you think there may be also in the future more uses?
Hunter: Yeah, I think so more as from the same point of the radiation oncologist with improved technology, we can see what we want to target better and the delivery of that high dose focused radiation becomes more and more accurate. So with that increased precision, I do think that more potential treatments will come about as we look at different avenues to try and help patients with this focus delivery of radiation.
So let’s talk about, let’s first talk about the problem with the ventricular tachycardia.
Cutler: So individuals that have heart disease or heart problems. This could be because of a prior myocardial infarction or heart attack. It could be because of some genetic abnormality. Or maybe we got a viral illness and it caused some injury or damage to the heart muscle, and that can lead to what we refer to as heart failure. Individuals with heart failure, heart disease, have a higher likelihood of having life-threatening arrhythmias like ventricular tachycardia. These are the type of arrhythmias that can lead to cardiac arrest and can cause death if not treated in a timely manner. And so trying to prevent or avoid these types of arrhythmias from happening, that becomes very important and can be potentially lifesaving. Ventricular tachycardia is one of those arrhythmias along with ventricular fibrillation. And the treatment for ventricular tachycardia has largely been focused at using medications that make the arrhythmia less likely to occur. Those medications that we often use are referred to as anti-arrhythmic drugs. So they reduce the likelihood of that arrhythmia happening. They’re not perfect, they’re not curative, and in many cases, they don’t fully do the job. And so we’ll see these arrhythmias come back even when they’re on the medicines. And when this happens, an alternative treatment option is what we refer to as catheter ablation. And that’s where we put IVs into the veins of the legs, put catheters up into the heart. And we look around and try and identify where these abnormal electrical signals are coming from that are contributing to this arrhythmia occurring. And with a catheter that can deliver electrocautery or heat, we burn those areas of heart tissue; that’s called catheter ablation. And by doing that, we’re trying to disrupt these abnormal circuits that can occur or develop in the heart, causing the ventricular tachycardia. There are times when even that treatment is not successful. And in the past, we haven’t had a lot of good options when individuals have either been too sick to tolerate that type of procedure, or that procedure hasn’t been successful even with multiple attempts. With this new treatment utilizing the stereotactic whole body radiotherapy, with improvements in technology, we can use the stereotactic radiotherapy as the ablation energy or tool to target these areas in the heart that are contributing to the arrhythmia occurring.
How did you know that that would be something that would work?
Cutler: That’s a good question. I think as Grant had pointed out previously, this was importantly pioneered to with some physicians at Washington University in St. Louis and has been performed at other centers throughout the country and throughout the world. And the premise is if we can deliver some sort of energy source, whether that’s heat or cold, or there are newer energy sources, the purpose is we need some sort of an energy source that can damage heart tissue. Because that’s what we’re trying to do. It seems counterproductive; why do you want to damage heart tissue? But what happens is we get areas of heart tissue that have some functional heart cells that are intertwined with scar or nonfunctional heart cells. And that sets up the framework where because of the electrical properties that develop in that situation where these types of arrhythmia circuits can develop. And so the ablation is really trying to smooth that out, if you will, to destroy the functional heart cells that are intermixed into this already injured area so that those heart cells aren’t there to cause the problem. And so the stereotactic radiotherapy is an energy source that can cause that type of damage. And with improvements in how that energy is delivered, we’re able to do it and the radiation oncologists are able to deliver that in conjunction with their physicists in a more precise manner. And so it allows us to hone in on a specific area in the heart to deliver that energy source non-invasively.
How does it compare? What you were describing sounded very uncomfortable the way it was done before?
Cutler: We still do that and that’s still the first line treatment in these cases. But those are more involved procedures, they’re invasive. We’re putting IVs and catheters into the heart. Patients are under anesthesia. So these are a little more, they take longer, they’re invasive. They have risks associated with invasive procedures. And they put a stress on the body. In this particular procedure, it doesn’t quite have the same precision. Like I can’t pinpoint it to a very small area like I can with a catheter. But it’s got enough precision that in the right patients, in the right scenarios, we can target that energy to the area we need to be targeted. But we can do it in a non-invasive way. They just come to an outpatient facility, they sit in a chair for 15 minutes. They get the therapy, they get up, they walk out. They didn’t have to have anesthesia. There were no needles stuck into blood vessels, nothing went into the heart.
With the procedure you’re talking about with the catheter, how long was that?
Cutler: So those procedures can be anywhere from three, sometimes six, eight-hour procedures with the associated stress of the anesthesia. In these very sick patients, sometimes that’s enough to cause them to be in an intensive care unit for periods of time as they recover from it. And so there are some patients that just, they’re very fragile from the standpoint, if you put a lot of stress on their bodies, they don’t tolerate that real well. In those patients like that or that have failed prior catheter ablations, this is a very promising new treatment option that really gives us another tool in our tool box, if you will, to treat these patients and perhaps extend their life and improve the quality of their life. In addition, in these very sick patients.
What are the side effects?
Cutler: Of the new? Dr. Hunter would be able to speak more accurately to the radiation side effects, but actual acute side effects are pretty limited. We’ve done now three cases here at Intermountain Health, and we’re just preparing for our fourth case. All of those patients have done very well. There are some cases where you can get a little bit of fluid around the heart sac that we have to monitor for because of the inflammation and sometimes we need to use a medicine that reduces that inflammation. Sometimes you can get some skin irritation from the areas but Dr. Hunter would be able to talk more specifically about the individual potential side effects from that treatment.
How big is this discovery as far as heart health for the heart?
Cutler: I think it’s early in our experience with this and so time will help us understand what’s the right patient population. Can we extend it into other patient populations? Is it the best energy source to use in a noninvasive way? Are there other options? But I think it’s an important advancement in that it gives us another tool in the treatment of very sick patients. It gets us thinking about ways to be more innovative and look at alternative approaches to the treatment of sick patients, and I think whether long term this has proven to be the best option, time will tell. If it’s not, it will have served as the stepping stone to get us to the better option and I think that’s as important as anything.
It seems, like, so far, so good?
Cutler: Yeah, our local experience has been very positive. Patients have done very well, both US and worldwide experience to date has shown some promising benefits. It doesn’t cure the problem, it’s not perfect, but it certainly has an important impact.
Did you treat Shannon Brooks?
Cutler: Yes.
Do you remember his case?
Cutler: Yes.
Can you speak on it?
Cutler: He’s a gentleman that had had a prior heart attack, a pretty large prior heart attack, and had a lot of scar in areas of his heart. He’s somebody that we had treated over an extended period of time, both managing his arrhythmia and then our other cardiology colleagues managing his heart failure. We had done prior catheter ablation on him and he had had recurrent arrhythmia even using medications and after the prior ablation. His heart function was declining. He was clinically just not doing well. And so we looked at the various options. Would he do well? Would he tolerate a repeat catheter ablation? Or what would be the best option in him, and after looking at all of the factors, decided that applying this technology to his case would be likely both the safest potentially and give us the best opportunity for success or making some meaningful impact in his case, and he’s actually done very well. We performed the procedure just about six months ago, not quite at this point and we’ve actually seen no subsequent arrhythmias from him. He hasn’t gotten any more shocks from his defibrillator since that procedure. And in his case somewhat unexpected by us, we actually have seen improvement in his heart function. His functional capacity has gotten better and some of that likely because he’s not having as much of this arrhythmia.
So, I imagine you will just continue to monitor him?
Cutler: We’ll continue to monitor him and treat him as appropriate.
So, he’s really at the forefront of this treatment?
Cutler: Certainly in this area. Like I say, this has been being performed at other academic centers pioneered largely at Washington University in St. Louis over the last few years. We’re the first center in Utah that’s brought this treatment option and he was really one of the first to be treated by as and from that standpoint right at the forefront.
Yeah. In this area, you’re saying, it’s going to be just like you’re going to keep an eye on him for the rest of his life, is that right?
Cutler: As long as he’s in this area, we’ll be providing his cardiac care and his heart rhythm care for sure.
Is there anything else you want to touch on that I didn’t ask?
Cutler: I think it’s just important to acknowledge that it’s a new treatment we’re learning as we get more experience with the treatment. It’s not a treatment that will be broadly used necessarily because it’s for a very appropriately selected patient; that appropriate selected patient may expand. We may be able to appropriately deliver that to a broader range of patients in the future. But I think right now, it’s for those patients that have failed other therapies and there aren’t a lot of other options available. I tell people what motivated me to bring this technology here to Inner Mountain Health was caring for a patient had prior heart attacks, ventricular arrhythmias. We had done prior oblations on him and he just wasn’t getting better, he kept having arrhythmias. We just didn’t have any other options to offer at that time and he ended up not surviving. And you go through cases like that and you think, where can we do better? What are new options that we can offer to our patients?
END OF INTERVIEW
This information is intended for additional research purposes only. It is not to be used as a prescription or advice from Ivanhoe Broadcast News, Inc. or any medical professional interviewed. Ivanhoe Broadcast News, Inc. assumes no responsibility for the depth or accuracy of physician statements. Procedures or medicines apply to different people and medical factors; always consult your physician on medical matters.
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