Justin Muhlenberg, MD, MBA, Interventional Radiologist at M & S Radiology Associates talks about the benefits and spreads awareness of microwave ablation to help get rid of tumors with minimal risk to patients.
Interview conducted by Ivanhoe Broadcast News in May 2019.
Briefly describe the difference between this new ablation in kidney and liver cancer versus surgery.
MUHLENBERG: There’s a lot of differences. Microwave ablation is minimally invasive. So, the incision made is only on the order of a few millimeters. The procedure is associated with less morbidity to the patient and the recovery is shorter. It’s an overall faster procedure. Also, the destruction of the tumor that we’re causing is limited to the tumor and a small rim of normal surrounding tissue, whereas when you’re doing surgery, you’re removing a significant part of the organ in addition to the tumor.
How does this strike you? Do you look at something like this and think finally?
MUHLENBERG: Yeah absolutely. This is a great procedure. This is one of my favorite procedures. When patients come in to visit me, they’re nervous. They’ve just got diagnosed with cancer. They’re obviously scared and they don’t know what’s going on. I can perform an ablation and after we’re done, I can tell the patient your tumor is gone. You’re cured. Its incredibly special to me to be able to offer patients that service.
So, I think people may not realize that when the other option is selected – the surgical option, we’ll call it, previous option – that takes a lot more time from start to saying to somebody, OK, we got it.
MUHLENBERG: Absolutely. However, in both treatments, you want to make sure you have appropriate follow up afterwards to make sure that the tumor does not recur. This is important whether you do surgical excision of a tumor or whether you do an ablation, such as a microwave ablation.
Describe what a microwave ablation is.
MUHLENBERG: Ablation is just a big word that means destruction of tissue. Microwave ablation is a technology that causes thermal ablation, so it uses heat to destroy tissue. It can get pretty scientific. It uses energy from the microwave region of the electromagnetic spectrum to cause friction which then produces heat, resulting in destruction of tissue. In clinical practice, it is simply a needle or a probe that you can insert into a tumor and you can turn the probe on and it delivers enough heat to cause destruction of the tissue around the tip of the probe in a spherical or conical shape. This destroys the tumor and a rim of normal healthy tissue around the tumor.
So next time I throw a frozen dinner into the microwave, is that a comparable situation?
MUHLENBERG: It is. The friction there is caused by molecular movement and the friction is causing your food to heat up. So, it’s the exact same principle. We’ve just taken it out of the microwave and brought it into the medical world.
Walk us through what you do with that probe.
MUHLENBERG: First, we actually stay out of the operating room. We do our procedures in the C.T. scanner room. The reason we do that is because we need the imaging. We use a combination of C.T. and ultrasound guidance to identify the tumor and then to guide the microwave probe directly into the tumor.
So, as you’re going through the surgery or the procedure, are you looking at ultrasound?
MUHLENBERG: Yes absolutely. The ultrasound provides a live visualization of the tumor and also of the needle so that in real time we can carefully place the needle directly into the tumor. It’s really important that you stay away from structures that you don’t want to ablate or pass a needle through, so the live imaging guidance is absolutely imperative. The C.T. images are a great compliment. They provide us with this information as well. Additionally, as soon as we’re done with the ablation we can perform a diagnostic C.T. scan, without even moving the patient, to ensure that we’ve destroyed the entire tumor. If there is any tumor left behind, we can simply retreat right there in the same room at the same time.
If it’s close to something like the ureter or something, then you use freezing – a cryo technique?
MUHLENBERG: It depends on tumor size, tumor location and the type of tumor. Most of the different types of ablative techniques we have available are thermal. Cryo-ablation uses freezing or forms an ice ball to result in tissue destruction. We also have radio frequency, which is another form of energy – nonradioactive energy, and that produces heat as well. The microwave has advantages over those technologies. The microwave produces a larger ablation zone in a shorter period of time.
Is this something that was a transferable procedure from something else?
MUHLENBERG: What we’re learning is that we can treat more and more tumors in different parts of the body with this technology. Initially, this technology was used primarily for tumors of the liver and of the kidney, but we’re also using it in lung and intra-thoracic tumors now. Additionally, we are using it in a palliative approach to bone tumors. Tumors that come from one area of the body and have gone to the bone are oftentimes very painful. If we can perform an ablation, we can help to eliminate or reduce the patients pain caused by those tumors.
When you cut into somebody you have a tendency, or it has a tendency to seed that cancer in other parts of that organ or body. This procedure doesn’t, right?
MUHLENBERG: Well it isn’t a tendency, but rather a risk. It’s very rare, however there is a risk of tumor seeding with all procedures performed on tumors. With biopsies and ablations there is a very small risk of seeding the tumor along the needle tract.
Describe to me how much of a difference this will be for the patient from start to finish, from diagnosis all the way to OK, we got rid of it.
MUHLENBERG: It’s a huge difference. The first step for the patient is to undergo a multidisciplinary evaluation of your tumor. We want to look at you as a person and consider the disease you have. Myself, as an interventional radiologist, in conjunction with surgical oncologists, urologists and/or oncologists, we make sure to come up with the right treatment plan for you. After that’s done, I’ll visit with you here in the clinic. We’ll go over your images. I’ll show you your images, talk about the procedure, discuss the other options you have, whether it’s surgery or ablation, and then we will agree on a plan for you. When you come in for the ablation, you know that you’re only going to be coming into the hospital for one day and the next day when you go home, you’re basically going to be able to resume most of your prior activity almost immediately. So, the downtime and the recovery are significantly different for a percutaneous approach such as this one as opposed to an open surgery. Most of our patients are feeling great the next day. They’re eating. They’re up and walking around. They don’t have a lot of pain. Whereas with surgery, recovery takes a little bit longer most of the time.
Under what circumstances would you prescribe the more radical invasive surgery over the ablation?
MUHLENBERG: The patients that aren’t good candidates for ablation usually have tumors that are too large. The most important criteria right now is tumor size. Currently, we can only treat tumors that are a few inches in size. They also have to be in a good location, a safe location, for ablation. If the tumor is not the right size or if it is in a bad location then we wouldn’t be able to offer the patient ablation and they would have to go onto surgery.
Do patients as a rule know about this? Is their referring physician telling them about this?
MUHLENBERG: No, absolutely not. There are very few people that actually know what interventional radiology is and what we do. I don’t think my family really even understands well what I do. So, for the patients – they have no idea. They hear from their doctor that they have a tumor and this or that is the treatment and that’s the end of it. We really need to do a better job of informing patients of the different types of treatment options we have available. One of the things we want to do is get the word out that you don’t have to travel to a huge cancer center to have this type of option. We offer it right here in San Antonio. We make treatment decisions in a multidisciplinary approach. We have the technology. We have the physician expertise to perform the procedures well and we have support staff that’s well-trained to take care of the patients who are in the process.
How long has this procedure been applicable to liver and kidney cancer, and how wide spread across the country is it?
MUHLENBERG: Only in the last 20 years have we been performing microwave ablation for kidney and liver tumors. You’ll find it done across the nation at specialized sites that have the equipment and the personnel and the training.
What’s the newest word that we can have the medical breakthrough thing on, and secondarily, if it’s been around that long, how come not that many people know about it?
MUHLENBERG: The reason why not too many people know about it is we don’t always do a great job of telling patients what their options are. Also, physicians in general are conservative people. So, it takes a while for us to gain trust in a new medical device or technology. There’s a long process after something hits the market where we do post treatment evaluation and we make sure it’s doing what it’s intended to do before we say OK, let’s go ahead and make the switch and make this the new standard of care. That’s a long process in the medical world. The breakthrough part of the technology is the fact that they are improving upon these devices so that we can create larger zones of ablation, which means we can destroy more tissue, which means we can offer more patients with larger tumors an ablation treatment. The size limitation becomes a little bit less stringent. So being able to do larger ablutions in a shorter period of time is really the ongoing goal.
Describe to us in fairly significant detail what you see happen with that – shall we call it a needle or a probe?
MUHLENBERG: Either term is fine, a needle or a probe. You can even call it an antenna, which is what the microwave companies call it. What we see in real time is we actually can watch the needle with ultrasound. Also, we see the tumor itself and its usually it’s moving up and down as the patient breathes. Then, we can slowly guide the needle directly into the tumor. As we turn on the microwave generator, we see that slowly the tissue gets destroyed. What’s going to be left there at the end of the procedure is just a scar.
Describe to us what the nurse or technician is dealing with the equipment while you’re involved in the actual procedure
MUHLENBERG: The nurse or technologist is helping by running the microwave generator and it’s relatively simple. It’s just a matter of tapping a few buttons on a screen that the needle is plugged into. Based upon my instruction, they’ll set the generator to the certain power and the amount of time we want to perform the ablation for. Those two variables are something we use to control the size of the ablation that we’re performing.
How many of these do you think you do in a year?
MUHLENBERG: We do around 50 a year. When you talk about a procedure that may not sound like a ton, but for ablations it is. We do more here at Northeast Baptist Hospital with M&S Radiology than any other private hospital in San Antonio and Austin or the surrounding areas.
Is this something that’s similar to an ablation for afib in the heart?
MUHLENBERG: It is. The way that the afib ablation is preformed is very different though. For that procedure they go in through the vasculature and they go into the heart. They find the area that has the irregular rhythm and they destroy that part. But they’re using the same technology, just in a different way.
Talk to us about how heat looks different versus cryo
MUHLENBERG: With cryo-ablation you can see the ice ball forming under C.T. imaging. The microwave ablation you can see under ultrasound. It looks like a little bright area at first. It starts to light up and grow like a snowball, if you will, until it encompasses the entire tumor. What you are seeing is the local destruction of the tissue. Then, afterwards when we’re done with the ablation, we do the diagnostic C.T. scan and there you can see that that the treated tumor is no longer alive.
The total time for this procedure?
MUHLENBERG: Total time is about an hour, however the ablation portion only takes 5-10 minutes.
You wake them up and essentially, they’ve got just a pinprick in their skin. Is that right?
MUHLENBERG: You wake them up and they’ve got a small incision, just a few millimeters and it’s covered with a Band-Aid.
As a physician, percentage wise, how confident are you when you walk into the OR or into the CT room that this is going to be successful?
MUHLENBERG: I would never choose a treatment option for a patient unless I was confident it was going to be successful. So, I’m very confident when I go in there to do the procedure that it’s what should be done and it can be done. It’s my job to do it the best and the safest that I can.
So, you don’t do the cutting procedure. That’s more of a surgical option, right?
MUHLENBERG: Absolutely. That’s a different specialty. In interventional radiology we perform minimally invasive, image guided procedures. We do many different types of procedures. The surgeons would do the actual surgical type removal an organ. We work closely in conjunction with them, having a multidisciplinary approach to patient care. When we decide that the minimally invasive treatment option that I can offer is the best option for the patient, we do that as a team.
In terms of outcome – surgery versus this micro ablation?
MUHLENBERG: So, for the appropriately selected patient, they’re equivalent. The cure rates are the same for the right patient.
With much less beating up of the patient?
MUHLENBERG: With much less beating up of the patient. Absolutely.
Interventional Radiology – Should patients be keying in on that word? That’s a good word for them, right?
MUHLENBERG: It’s a great word. It’s a new word in the medical profession. It’s not something that has been around forever. Interventional radiology, as a specialty, isn’t very well known. Anytime we can do something that obviates the need for a major surgery and we can get the same goals accomplished, in a minimally invasive fashion, it’s a great thing.
Should patients take it upon themselves to be aware of these different things to advise their referring physician for example
MUHLENBERG: It’s great if you can do that as a patient, but you’ve got so much else going on. You have to deal with the fact that you’ve just been delivered some bad news and how is that going to affect you and your family. It would be ideal to get this word out to the surgeons, the primary care physicians, the oncologists, the physician assistants and the nurse practitioners. The important thing is, if we find a tumor early, we have a lot of options for it. We’re finding a lot more tumors these days because we’re doing a lot more medical imaging. So when somebody comes in and they have a CT scan for abdominal pain and we find a small incidental tumor on the kidney, it’s important that we then start to bring those patients into the office and have them educated on the procedure so they can be treated appropriately.
Cost comparison between the two?
MUHLENBERG: I try to stay out of the financial portion when I practice medicine, as much as I possibly can, but It’s cheaper, I’m sure.
Cheaper, shorter time of healing and less invasive on the patient.
MUHLENBERG: Yes to all. The healing time is shorter. Patients return to their normal lives quicker. The morbidity is less. The complications are less.
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.
If you would like more information, please contact:
Natalie Gutierrez, PR Baptist Health
210-297-1028
Natalie.gutierrez@baptisthealthsystem.com
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