BackTable / Urology / Podcast / Transcript #30

Podcast Transcript: Minimally Invasive Focal Therapy for Prostate Cancer

with Dr. Amit Patel and Dr. Ranko Miocinovic

Dr. Amit Patel, Dr. Ranko Miocinovic, and Dr. Jose Silva discuss focal therapy for prostate cancer and share their experiences with the NanoKnife System from AngioDynamics. You can read the full transcript below and listen to this episode here on BackTable.com.

(1) Initial Workup for Prostate Cancer

(2) Focal Ablation Therapy for Prostate Cancer

(3) The NanoKnife System

(4) Pros & Cons of NanoKnife Ablation for Prostate Cancer

(5) NanoKnife vs. Radical Prostatectomy

(6) NanoKnife Procedure Tips

(7) NanoKnife Ablation Follow-Up Care

(8) Future of NanoKnife Ablation in Prostate Cancer

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[Dr. Jose Silva]
Hello everyone and welcome back to Backtable Urology podcast, your source of all things urology. You can find all previous episodes of our podcast on iTunes, Spotify, and backtable.com. The NanoKnife system from Angiodynamics is an ablation technology that harnesses the power of irreversible electroporation to destroy diseased tissue without the need for thermal energy with the NanoKnife system, you can sculpt and control the ablation zone through multiple electrical configuration effectively destroying, targeted tissue with precise treatment margins. The unique non-thermal mechanism of action allows you to spare vital structures within the ablation zone, and enables treatment to be performed in all segments of an organ. Reimagine your treatment at nanoknife.com and alert about the ongoing preserved study for intermediate risk prostate cancer patients The NanoKnife system with six outputs is indicated for surgical ablation of soft tissue. Visit angiodynamics.com for important risk information.

This is Jose, Oche Silva, your host this week, and I'm very excited about this episode. We have two guests today. We have Dr. Amit Patel and Dr. Ranko Miocinovic; both are urologists in Duly Health and Care in the Chicago area. Dr. Patel did his residency at Cleveland clinic and then a fellowship in urologic oncology at the university of Chicago and Dr. Miocinovic, we did our residency in Toledo and then a fellowship in urologic oncology from Cleveland clinic. So Amit and Ranko welcome to backtable.

[Dr. Amit Patel]
Thank you, Jose.

[Dr. Jose Silva]
Today, we're going to talk about prostate cancer and using focal therapies to treat it. So, let me ask you a couple of questions regarding the logistics on how you see patients. Are you guys mainly receiving patients directly for treatment, or are you also in the process of diagnosing, uh, doing PSA all that, how's your practice?

[Dr. Amit Patel]
Thank you, Jose. So we are actually doing both, we are in a large, multi-specialty practice in the Chicago area. Uh, we have a big, primary care base and we have a group of 17 urologists in our practice. And the majority are general urologists, so they see everything. And then a few of us are oncology trained.

And so we see our own patients for elevated PSA and we diagnose prostate cancer as well as, we get referrals from our partners as well as from other physicians in the community.

(1) Initial Workup for Prostate Cancer

[Dr. Jose Silva]
Okay. And when you see those patients with elevated PSA, do you do a biopsy? Are you doing only MRI? I mean, are you always doing an MRI prior to a biopsy? Depends on the case? How are you guys approaching these patients?

[Dr. Amit Patel]
So probably around 2013, when the data on MRI first started coming out, we started to do MRIs working with our radiologists. So as early as 2013, Doing MRIs prior to biopsies. And now essentially, every patient who comes in with an elevated PSA, that's going to go down the road for a biopsy is going to get an MRI before the biopsy. So that's our practice.

[Dr. Jose Silva]
So unless for some reason they can not go on the MRI, then you will do just a standard biopsy, but other than that, do the MRI. Then when you go and do the biopsy are you doing peroneal, transrectal?

[Dr. Ranko Miocinovic]
Yes. So we are transitioning from a transrectal approach to transperineal approach. Dr. Patel and myself are mostly doing transperineal at this point. We do have a lot of our partners who are still doing transrectal approach and it's a slow transition if you will. But in our area here, I can tell you as well that, a lot of academic places have all transitioned to transperineal.

So it seems to be happening quite a bit in our area of the country. I would say more than 50%. I think urologists here are probably doing a transperineal approach.

[Dr. Jose Silva]
Are you doing these in the OR, ambulatory setting, or the office? How are you doing these?

[Dr. Ranko Miocinovic]
We're doing all of our biopsies in the office setting under local anesthesia. We acquired the Pro-Nox system not too long ago, for other reasons, mostly for the Urolift procedures that most of our partners do. But, every once in a while we'll actually use it for our transperineal patients.

However, to be honest with you, they tolerate local anesthetic pretty well. And it's not often that we employ this for, uh, you know, our biopsies.

[Dr. Jose Silva]
Yeah good to know because right now, I'm doing them transperineal and it's I guess it’s logistics in terms of OR time. I do it in the OR. We're getting the Pro-Nox in the office so I can speed it up, but right now, for some reason anesthesia, if the patient's supine they're not comfortable just doing the propofol. So we're working on that. but definitely, trying to do the transperineal, uh, less infections. Are there any other benefits of doing the transperineal approach?

[Dr. Ranko Miocinovic]
I think that I speak for Dr. Patel and myself, since we're champions of this in our group, you know, we do feel that you may have a better biopsy of the anterior zones. In prostates, where you may need to push harder to get to the anterior zone transrectally.

I think that you may probably have a better access, with a transperineal approach. And of course the infection thing is, with no doubt, a huge benefit.

[Dr. Jose Silva]
Perfect. So, let's say that the patient comes back to your office, Positive biopsy for prostate cancer. What’s the next step? How does that discussion go? Do you go into possible treatments? Do you only through the staging how's that process?

[Dr. Amit Patel]
So in our practice, we have radiation oncologists that we're partners with. And so, any patient that sees Ronco or myself for prostate cancer, newly diagnosed prostate cancer…they come through our multidisciplinary prostate cancer clinic. So, they're seeing myself, and you know, with them, I go through the pathology, the staging imaging, if we've, you know, MRI usually is the first staging imaging that we're doing even before the diagnosis.

So we go through that, the pathology, the prognosis, and then I talk to them fully about all their treatment options, including radiation surgery, and then alternative options as well. Then they meet our nurse navigator and then they actually subsequently go to see the radiation oncologist right after.

So we have interconnected offices. And so they see the radiation oncologist in their office to discuss radiation as the two main options for treatment.

[Dr. Jose Silva]
So even, in that first visit or post-op visit, they already talk to the radiation oncologist?

[Dr. Amit Patel]
So in that first post biopsy visit where they have newly diagnosed prostate cancer. Yeah. It's something that, you know, we picked up from just our training at Cleveland clinic. They're seeing us for all of the diagnosis information and treatment options. And then immediately they are seeing radiation oncology.

As most patients have localized disease, you know, about 80% are presenting with localized disease. They're going to see the radiation oncologist with us. so it's a multi-specialty multidisciplinary approach essentially to give that patient all of the information about their treatment options.

[Dr. Jose Silva]
And are you guys seeing a lot of active surveillance for example, me, when I started, I started doing MRI biopsies two years ago, and I haven't seen that many patients now that I'm doing MRI guided, for active surveillance. Is that something that you guys are seeing?

[Dr. Amit Patel]
Yeah. So I think you kind of mentioned it. With the MRI, we're diagnosing probably less insignificant cancers, so we're not, cause we're not biopsying if there's not a significant lesion. And so we're seeing less of the Gleason sixes. Those patients who have persistently elevated PSA, negative MRI, and some risk factor that undergo a biopsy anyway, if they have Gleason six, yes. A majority of our patients are localized Gleason six low-risk prostate cancers. I would say about 75% of them, reviewing our data, are undergoing active surveillance.

[Dr. Jose Silva]
And Ranko. So do you have any special algorithm for a patient when you see them in terms of, let's say, you do the full staging and then, do you have a specific procedure, or how does it go? Do you leave it up to the patient? How's that in terms of favoring one versus the other?

[Dr. Ranko Miocinovic]
Yeah, that's a good question. So with our multidisciplinary approach, uh, really, we try to present patients with all options, you know, surgery, active surveillance, watchful waiting, radiation, brachytherapy. And really, you know, let patients know about the pros, cons and risks of all of those approaches.

And we try to have patients decide what fits their lifestyle, quality of life and what they're willing to take as risk factors. Both Dr. Patel, myself, you know, we're surgeons obviously. But we really try to have non-biased approach to the way we take care of these men. And now in the most recent times, you know, we are adding this other arm of focal prostates ablation as well.

The algorithm is we talk about everything openly and try not to be biased towards one or the other.

[Dr. Jose Silva]
How about you? Same thing?

[Dr. Amit Patel]
Yeah. So, you know, we practice very similarly. We do like to offer to educate the patients on all their treatment options. That's one of the great things and probably one of the curses of prostate cancer is that patients have a lot of options for treatment and management. And I think sometimes for patients, it can be very confusing, which route they want to take.

They’re afraid of going down the wrong route or making a mistake and they can't come back. You know, for example, one of the things we talk about is if they have radiation, you know, there's a potential that surgery is then more difficult or can't be done after radiation therapy. So we do like to educate all of our patients on the pros and cons of each therapy, how nothing is a hundred percent cure rate, you know, surgery or radiation. And I think for us that's been helpful. It's really been helpful for our patients, to get educated in that manner.

(2) Focal Ablation Therapy for Prostate Cancer

[Dr. Jose Silva]
So let's talk about ablation. Okay. I'm very naive. So I'm going to ask dumb questions. So when do we talk about ablation? Are we just talking about focal therapy? I mean, for example, a patient that has cancer throughout the prostate, is that a candidate for ablation or are we just talking about focal ablation?

[Dr. Ranko Miocinovic]
No, that's a very good question. And I will take a step back just to sort of paint the background on this. I think that we have these wide categories of cancer who have low-risk disease. Then we have intermediate risk disease, which is classified into favorable and unfavorable disease and then we have high-risk prostate cancer.

And so I think high-risk, I don't think there's much question that that needs aggressive treatment. Low risk, I think there's been a lot of studies showing that active surveillance has been safe and it has become almost a standard of care in our practice that most men get.

But I think the most interesting category now becomes the intermediate risk, especially those patients who have three plus four or group two, and then a volume of group three patients, you know, three, four plus three disease. And a lot of the times, you know, the question comes up to me is, they have two or three cores and the patient will say doc, but can't you just take that part out and leave everything else alone in order to prevent these horrific side effects, potentially sexual dysfunction and, uh, voiding dysfunction.

So when you scratch your head, you say to yourself, huh, that's a very interesting point. Those are, that's probably the population that would potentially benefit from a focal ablation, which is what Dr. Patel and I are interested in as a primary therapy. Ablation of course can mean ablation of the entire gland.

And Dr. Patel can touch upon this later on. He does a lot of salvage cryoablation therapy in the setting of previous radiation. He can elaborate on that, but I think in terms of primary therapy, for now we are interested in offering, you know, focal ablation, which is, I think much more attractive to patients instead of bleeding the whole gland.

And, uh, it has pros and cons. As you mentioned, prostate cancer is a multi field disease. So I can say, hey, what about the other side? Are you at risk of developing cancer there? And why don't you just take it all out at once? And I think that's a very good question, but, I think that Dr. Patel and I talked about this recently as well, and we're trying to get those patients from potentially intermediate risk downgraded and back to low-risk again, if they do have additional Gleason six.

We're essentially going back to active surveillance on them. And that's the approach that we are taking. And just one last comment that I'm going to make about ablation, you know, there's many different forms and therapies that are being done right now. I think we counted last night as we were looking at this up to seven different types of formats, some of thermal, non-thermal, you know, some use cryo, some use radio-frequency some use photodynamic therapy, brachytherapy as you know. So, the times we're living in right now are very exciting because all of these are on the table and people are kind of doing studies within each area and trying to figure out what's going to be the most effective and yet the least destructive, if you will, option for these people.

(3) The NanoKnife System

[Dr. Jose Silva]
And you guys are doing NanoKnife. That's your main ablations source. So when you say NanoKnife, I mean, what are you doing with it? Well, what type of, is it energy or frequency? What is a NanoKnife?

[Dr. Ranko Miocinovic]
NanoKnife is also known as irreversible electroporation, or IRE. And that's essentially using an electric current to simplify, to break up the membranes of cells, and destroy them in such manner. The interesting thing about this technology is that it preserves the connective tissues and it minimizes destruction of the nerves.

So for example, you know, not to pull away from prostate cancer, but many centers and surgical oncologists are using it in treatment of pancreatic cancer in those tumors that are wrapped around the aorta or inferior vena cava, around very important structures. And they're able to literally ablate on top of these vessels, very safely and cause no damage because it doesn't destroy the connective tissue and the skeleton with these structures.

And so that idea is also hopefully going to translate into what we're doing here. And there's multiple studies to show that, the safety of that. but it is a non-thermal energy, basically.

[Dr. Jose Silva]
No Thermo. Okay. And does it have a radius of effect on the prostate? when you decide that you're going to go for ablation with a patient, does the size of the prostate matter or the size of the lesion on the MRI? That's how you guys do it through the MRI correlated with the biopsy?

[Dr. Ranko Miocinovic]
I think that, uh, I'm gonna, you know, Dr. Patel can jump in here anytime, but the size of the prostate does not matter. And the size of the lesion does not matter, with this approach. You can, I mean, if you want it to take out the whole prostate, you could. But what you're really treating with this technology is most likely quadrants of a prostate gland. So these probes that we use, they have different lengths. So you can adjust anywhere from 1.5 centimeters to two to three centimeters at a time. And they have a certain length beyond the tip and the base five millimeters, each direction you can cover. And so by placing these probes carefully within the prostate gland, you know, 2, 3, 4 probes, whatever, you can outline an area of the prostate and treat as big as you want, or as small as you want. So you can really adjust according to your lesion size and location. This is how you're able to spare nerves and important structures.

[Dr. Amit Patel]
So I'll just add in, into that, that comment, for NanoKnife, the electricity is going through, the currents are going through two probes at a time. So these are needle probes that are, 17 gauge needles and they're going, strategically placing them, in the prostate, through a transperineal approach, you know, using a brachy grid and ultrasound guidance.

And the geometry of the probes and the number of probes that we use helps to dictate how the ablation zone is going to play out. So, if you use two probes, your ablation zone is almost like a cylindrical pill with, you know, rounded ends. If you use three probes, it's more of a triangular shaped zone. And if you use four probes, depending on how you're placing it, you're getting a more rounded cube like ablation zone, and 3D. So depending on your lesion size and how the lesion is within the prostate, you can adjust how many probes you're going to use to get an adequate ablation zone.

[Dr. Jose Silva]
And right now I have seen the templates that the radiation oncologists do for a focal ablation. Is it those images, or right now it's just like mental image that you create in your head. And then you go by what you see on the MRI, how's your approach to when the patient already said, okay, let's do an ablation. How is that approach to decide how many treatments you’re going to do?

[Dr. Amit Patel]
So for focal ablation of prostate cancer using NanoKnife, we are confirming, with MRI, that there is a focal lesion. We do systematic biopsies as well as targeted biopsies of the lesion. Many folks are using MRI fusion guided biopsies. In our practice, since the start we have been doing more of a cognitive approach, so we have high quality ultrasound, many times we're able to see the lesion on the ultrasound that we're biopsying. So when we do our transperineal biopsies, we're approaching it. We're able to see these lesions on the ultrasound and target them directly without using a fusion approach. So when it comes down to treatment of these lesions, it's the same concept. We have a high-quality ultrasound and we're targeting these areas that we can see on ultrasound. As well as using a slightly wider approach. So we're not doing a micro-focus around the tumor. We're probably taking about a five millimeter margin when we're ablating these tumors.

[Dr. Jose Silva]
And I think Ranko, you mentioned this before, you talked about a three plus four and four per three, two or three, positive biopsies, same area or one positive biopsy. Would that be the ideal candidate? I mean, or who's the ideal candidate right now?

[Dr. Ranko Miocinovic]
Yeah, that's a good question. So I think that clearly some of the data that was presented by the groups in Europe and Australia. there were certain series that showed recurrence in up to 30% of patients. And, you have to be, I think careful who you offer it to, obviously we're not going to be offering this to patients who have Gleason eight or higher because of the risk of metastatic disease and et cetera.

I think that Dr. Patel and myself have sort of agreed to offer it to any man, age wise who may have minimal, three plus four disease. And I think for those men who have four plus three disease, we would offer it in the setting of an older patient population, uh, maybe who are, who have other comorbidities, and who are not great candidates for surgery and who may not want to undergo radiation either. So I think four plus three is perfectly fine. I just am not comfortable yet at this time offering to my 50 year old guy, for example. And this is why I think it's going to be important that we have long-term follow-up on this. I think we have short and intermediate term follow ups with these studies, but something on a longer term basis may convince me otherwise.

But for now, three-plus for anyone. And four plus three for the older guys with other co-morbidities and Dr. Patel, you can, you know, answer this as well, but this is sort of our stand for now.

[Dr. Jose Silva]
And three plus four, only one lobe, two lobes?

[Dr. Ranko Miocinovic]
Yeah. I think that, uh, we want this disease to be on one side of the prostate. So essentially, you know, we feel that we can get hemi-ablation done if we had to, once you have disease, you know, both sides of the prostate. I don't think we would offer this at this time. So we are interested in offering to those men who have a disease, mostly left or right side of the prostate.

[Dr. Jose Silva]
And when you talk about the ablation I forgot ablation. I mean, what are the pros and cons that you talk to the patient about? I mean, definitely recurrence is a con, but, what else do you talk about?

(4) Pros & Cons of NanoKnife Ablation for Prostate Cancer

[Dr. Amit Patel]
Yeah. I think the pros of ablation are that, and the pros of any ablation are, you're trying to minimize the side effects and maintain quality of life in patients while still treating the cancer. And so with the different types of ablation therapies that I've done, you know, one of them specifically is cryoablation and there's a lot of studies on focal cryoablation of the prostate.

But cryoablation, as you know, is a thermal based therapy. You're freezing the prostate and you're freezing whatever zone is within that ice ball. Everything is destroyed. It's dropping a little bomb in that region of the prostate. So your connective tissue, your blood vessels, your nerves, some of the surrounding area around that ice ball is, there's thermal damage created.

One of the pros that we're seeing with NanoKnife and with other athermal approaches that may emerge, is that you're not damaging the connective tissue, the collagen structure, the nerves, and the blood vessels, that are around surrounding the prostate as well as within the prostate.

So your scar tissue formation, your side effects of erectile dysfunction are going to be a lot lower. In addition, you're not, significantly causing damage to the urethra as well. One of the, concerns about cryoablation is we have to use a urethral warming catheter, and we do have to maintain a certain distance away from the urethra to not cause sloughing, or even, strictures within the prostate or within the membranous urethra. In our early experience with NanoKnife, we have not seen that. We can be close to the urethra. You'll have a zone of urethra that's even treated with the current, but it's not causing damage to those, to that endothelial tissue. And so there may be some swelling but not damage. And I think that's a really important aspect when you're thinking about ablative therapies. And certainly the pros of NanoKnife is that you're not going to have significant, uh, scarring and scar tissue that's developing in these patients.

[Dr. Jose Silva]
Ranko mentioned that you were doing salvage. Quick cryo question, for some patients were you doing before a primary treatment I mean, primary, first step.

[Dr. Amit Patel]
I've been doing cryosurgery really since the days at Cleveland clinic. And that's where, you know, there was a gentleman, J Steven Jones doing it out there and so I trained under him and he was doing a lot of primary therapies as well as salvage. And so my practice primarily has turned into a salvage cryoablation. So patients who are failing radiation brachytherapy or external beam, if they have recurrences, we are treating them with either focal cryoablation, based on MRI and biopsy, or whole gland cryoablation. I have also treated primary tumors with cryoablation. but mostly my practice is salvage.

[Dr. Jose Silva]
And what more or less, same indication that you had for cryo you're using for the NanoKnife?

[Dr. Amit Patel]
So, currently I haven't done, we haven't done any salvage therapies using the NanoKnife it's mostly for primary tumors, that have been untreated.

[Dr. Jose Silva]
But for primary, I mean, compared to the experience that you had before with cryo for primary treatment, what is the difference in terms of outcomes that you're seeing in terms of how the patient feels.

[Dr. Amit Patel]
Yeah. So our, our early experience, uh, you know, one of the biggest benefits is that with cryosurgery, I don't know if you recall at one point, urologists replacing suprapubic tubes, uh, at the time of cryosurgery because of the risk of retention afterwards. In my practice, I leave a catheter, a urethral catheter for seven days for cryo, for NanoKnife, uh, we're leaving catheters for three days.

So I think there's significantly less swelling, less risk of urinary retention after the procedure, the perioperative time, the time operative time is actually lower for NanoKnife then cryoablation. Typically for any cryoablation, whether it's whole gland or partial or focal ablation, it takes about an hour and a half 90 minutes of time. Sometimes up to two hours. With NanoKnife, we're seeing, much faster operative times, anywhere from 45 minutes to an hour. So treatment time is a lot quicker. We’ve been doing our NanoKnife cases in a freestanding outpatient surgery center so these cases are outpatient. The patients do require paralysis for NanoKnife, they don't require that necessarily for cryoablation. But I think the biggest benefit is that less swelling in the prostate, lower risk of retention after the procedure.

(5) NanoKnife vs. Radical Prostatectomy

[Dr. Jose Silva]
And you guys both do a lot of, radical prostatectomies, robotic. Let's say the same patient, the same 50 year old patient. Two core, same side of 3 plus 4. Will you push that patient to do a focal ablation or how do you go? Do you just put everything up front and then let the patient decide? If they tell you, hey, if it's your father, what will you do?

[Dr. Amit Patel]
So current, you know, when we talk about these therapies, and I think that's a great question for all of us that are sort of getting into these emerging therapies. You know, first and foremost, we do tell patients that this is not standard of care yet. And so, tell them that it's, it's still, we're still studying it.

And there's, you know, we have a clinical trial that we're actually about to start. and so, we're going to be enrolling patients into that clinical trial. First and foremost, that's what we say that this is something that's emerging. It's not standard of care. And we describe it. But I think, you know, one of the other benefits and we didn't get into this, of NanoKnife is that, or at least what I'm seeing and from the studies out of Australia and Europe, is that because of the lack of thermal damage, there's no thermal damage to the tissues.

If a patient has a rare infield or an out of field recurrence. So an area that wasn't treated that recurs with cancer, those patients can still undergo all of the therapies as if they were starting over. So, they are still candidates for surgery. For radical prostatectomy, they are still candidates for radiation therapy and if it's the untreated area, they can still be candidates for ablation of that area too.

So I think that makes something like NanoKnife more appealing.

[Dr. Jose Silva]
And have you guys done prostatectomies after ablation after NanoKnife ablation?

[Dr. Ranko Miocinovic]
No, we have not done prostatectomies after NanoKnife, we have spoken to people who have, and, they don't find them more difficult than routine prostatectomies. So that's another huge plus in my eyes is that when I talk to patients about this and I do sound very excited, I must say because, I am excited about this focal technology.

I do tell them, and it's kind of like, you know, idiot proof, if it persists, six months from now and the disease is still there, we do a biopsy and if you choose to, proceed with prostatectomy and radiation. We can still do it, which is great and really with minimal to no risk, you know, as if they never had this done. So I think that's another huge attraction why we picked up this particular technology, to use in our group.

[Dr. Jose Silva]
So let's talk about the setup, so, okay. So, you guys decide, or the patient decides to go to the ablation. Uh, you mentioned that the patient is going to have a transperineal approach. You give them any specific antibiotic?

[Dr. Amit Patel]
Just general prophylaxis antibiotics. So, Ancef typically is what we give.

[Dr. Jose Silva]
That's what you usually do for biopsies also, or you do something different?

[Dr. Amit Patel]
Well, in the past for biopsies, we were using, more or less, Bactrim, rarely Cipro or some type of IM ceftriaxone or combination of an IM tobramycin or gentamycin plus an oral, um, with our transperineals we're actually reducing, the antibiotic we're still using Keflex, more skin antibiotic, but I think, uh, in general centers who have done a lot of these are, are actually stopping antibiotics now with, with the prostate biopsies that are done transperineal.

[Dr. Jose Silva]
So I will, you mentioned, about how you decide how many probes and, on the depth or the size of, the lesion. So let's say if the patient has same lobe or different areas, how you will treat those lesions?

[Dr. Ranko Miocinovic]
So you know, let me just paint a picture of a patient who may have Gleason six on the left side, Gleason three plus four, the right side. But you have it at the apex and the mid gland, or apex and the base. The approach that we would take in this case is that we will leave the left side alone with the Gleason six, and that would be our active surveillance option or, moving forward, that's how, we would follow that. For the right side where you have the apex and the base, we have the option of setting our needles at the base of the prostate, treating that area and then pulling the needles back and then treating the apex area. Or you can also, just treat it almost like a hemi-ablation, by widening the exposure of those needles.

It all depends on how big your prostate is. If your prostate is only, you know, three or four centimeters, then you may be able to get those areas in one sitting. If your prostate is five or 6 cm long, it's bigger than that, you may want to consider this pullback approach. So you can treat it that way.

I just want to mention the study, the preserve study that we're involved with. So these patients are then followed basically by having PSA's every three months for the first 12 months. They would have a repeat MRI, at three to six months and at 12 months, and at 12 months we would repeat a biopsy and we would be looking for recurrences within the treated area or infield.

That's the primary goal of the study. Now you may pull the trigger and do a biopsy or MRI quicker or faster, or sooner. If yourPSA kinetics don't fit, what you think is appropriate. If they're changing, if there's issues going on, you can do it sooner. But this is kind of the approach that we have been doing so far in our group and as well in this study protocol that we're going to embark upon.

Hopefully this answers this.

(6) NanoKnife Procedure Tips

[Dr. Jose Silva]
Definitely. For patients that have BPH or symptomatic symptoms, lower urinary tract symptoms, do you guys do anything before ablation or, in terms of surgery, what do you guys do for those patients who have urinary symptoms and prostate cancer?

[Dr. Ranko Miocinovic]
You know, just to add to this, I have added steroids to my patient. I've stolen this concept from the Urolift people and brachytherapy people. And I think Dr. Patel and I, for patients who have significant prostate issues, we would give them a dose pack of steroids. It’s a solumedrol 5-6 day course immediately after surgery to be taken, to minimize the swelling and the edema that this causes. But I think that, the way we would treat with these patients is just like with any other patients where, who has radiation, for example, we have tons of those patients in those cases. I will wait, you know, nine, six to nine months until radiation is done and offer them TURP. People are now doing Urolifts as well. You know, a lot of those patients. So I don't think this is going to be any different than what we have been doing routinely for the other population.

[Dr. Jose Silva]
And so let's talk about the procedure per se. You mentioned it goes from one probe to the other and as the area of electrocautery, I guess, or damage to the prostate from one probe to the other, am I right by saying that?

[Dr. Amit Patel]
Yeah. So you're placing your probes in a strategic sort of geometric position. So you're essentially lining up your probes to surround the lesion that you're treating and the probes have to remain parallel to each other. So that's really important that they’re equally spaced and parallel from the tip of the probe to the back of the probe.

And so ultrasound guidance helps you.

[Dr. Jose Silva]
And that's in contrast to other ablation that essentially the probe generates some things around the probe versus this one that the probes essentially, you place them at the limit of the lesion.

[Dr. Amit Patel]
Yeah, it's actually, that's a great point, Jose. So, you know, in cryosurgery you're essentially placing your probes directly into the tumor. and then you're building an ice ball around that or, you know, pulling a couple of probes and then the ice balls will connect to ablate the entire larger tumor like a hemi ablation here.

You're more or less surrounding your lesion with these electrodes, these electrode probes. And then the way the technology works, the electricity is going to cycle from one probe to the other, and then alternate to the next probe and then the third probe. And then each of the probes has current going through them.

And so there's a whole cycle. And the more probes you have, the more cycle events are going to occur between each of the probe sequences. There'll be more sequences. And as the electricity's going through from probe to probe, that's, what's creating the ablation, irreversible electroporation and causing the cell death zone.

[Dr. Jose Silva]
And how you do know when it's done? I mean, do you go by the ultrasound? Do you, the machine tells you to stop?

[Dr. Amit Patel]
Essentially the machine cycles through, each of the probes, at a sort of defined limit and then it stops. So you'll have a sequence of treatments and then it stops. During that time you're monitoring your wattage so you know, electroporation is athermal current, but you're monitoring your wattage because at a certain level of energy, it can become thermal so you do monitor, that energy that you're sending to make sure that you're in that athermal zone.

And that's all done through the probes.

[Dr. Jose Silva]
I forgot to ask you in terms of the sides of the lesion. I mean, do you factor in what you got from the biopsy? The percentage of the biopsy that was positive. Does that play into this or do you go by imaging?

[Dr. Amit Patel]
We mostly go just by imaging. I think your percentage involvement. That's what you're asking. Percentage involvement of the core. You know, if you're targeting directly into that lesion, you're going to have a higher percentage of core involvement because you've targeted that lesion as opposed to when you were doing random biopsies.

So I think we tend to have on our targeted biopsies, we tend to have a higher percentage regardless because we've targeted that area. So we go mostly based on the imaging and the location of the positive biopsies.

[Dr. Ranko Miocinovic]
I just want to add, I know it's hard to conceptualize this, but focal ablation is not like you’re taking five millimeters and treating five by five millimeters. This really, electric field effect that's being caused. I mean, you're really, in my opinion, treating probably, quarter of a gland.

So, what I like about it is that yeah. You know where this lesion is located. But you don't have to just precisely by millimeters be right on it or around it. In essence, this is gonna ablate that entire area of the prostate. And I think that's why, even this cognitive approach that we're talking about makes sense, because you're going to ablate a certain wide area of the gland and Dr. Patel wants to say something.

[Dr. Amit Patel]
I think that's a great point because the technology has less side effects and less, no thermal damage and less side effects. It does mean that you can go wider without risking, or compromising, side effects and morbidity to the patient. So, you know, one of the things I didn't mention, which is really important, is that in cryosurgery, you can't make that ice ball as big as you want, because you're going to risk injuring the rectum and other structures, like the side wall, the muscle and the pelvic floor. With NanoKnife you can get right up to the edge of the prostate and treat that zone even slightly outside of it without significantly injuring or damaging the nerves or the neurovascular bundle.

And I think to Ranko's point that's an advantage.

[Dr. Jose Silva]
Yeah, that definitely. And I guess that the difference that that brings to the table. Uh, we’re used to RFA, to cryo, things that cause ablation outside the probe and you really cannot measure how much damage you're doing. Uh, and in contrast to this, that you can say, I went from this point to this point and everything was going to be targeted.

[Dr. Amit Patel]
And I have to tell you, Jose, just, you know, anecdotally, before we started with this therapy, we had a surgeon, surgical oncologists in our hospital system here who was using NanoKnife on his pancreas treatments. And so we talked to him before we actually approached and started doing this in our patients and the way they use it is they put those probes directly right on the SMA, you know, around the SMA where the pancreas and the tumor might be enveloped, around the SMA and they ablate that area. And then they go in and surgically remove it while preserving the SMA and they're able to remove the tumor. Now, the idea in those cases is you can't cut into the SMA or damage the SMA.

And so what you're expecting with the NanoKnife is that any tumor cells left in that region have now been killed and then they immediately go in and resect the pancreas and whatever tissue they may have left on the SMA or the aorta that was treated with the NanoKnife and is essentially, going to be dead cells. And they found a very favorable response.

[Dr. Jose Silva]
Yeah. Yeah. I remember in residency seeing those patients, if SMA was involved, that was it for those patients. I mean, not now. Definitely they're doing more stuff, but back in the day, that's how it was. So let me ask you this. So after the treatment, you mentioned the three days Foley, do you have to do a cystoscopy afterwards for anything?

[Dr. Ranko Miocinovic]
That has not been our standard practice at all. I know, you know, I think that that the cystoscopy concept came probably from brachytherapy seeds that people would sometimes drop in the bladder, but there's no such need for this treatment.

(7) NanoKnife Ablation Follow-Up Care

[Dr. Jose Silva]
And have you had patients that after three days, they still have retention.

[Dr. Ranko Miocinovic]
No, I have not seen that yet. We have followed our patients obviously very closely and they may have some minor symptoms the week after the Foley comes out. And I mean, very minor. Some men have experienced hematospermia for up to a month. And I would say it's very comparable to the prostate biopsy side effects.

I mean, that's really what you're seeing and they’re extremely happy.

[Dr. Jose Silva]
Good no and it is good you mentioned, I think it was, someone made the mention that at least a 55 year old, 50 year old with good erections. You're giving them recourse in 10, 15 years then. I mean, who cares? I mean, so at that time you can do something else, but, at least you gave him more time, no sexual side effects for longer. So you have been following those patients for a couple of years.

[Dr. Ranko Miocinovic]
No, you know, we just started about a year ago. So our experience so far has been very, very short term. We're actually starting to do some of the first, rebiopsies now at this point, looking for the infield recurrence and see how things are going. So, this is why in this, you know, in our hands, in this country, this data's pretty, new if you will.

But you know, a lot of our stuff that we have analyzed comes from Europe and Australia, and those guys have been doing it for 10 years. with some pretty impressive results.

[Dr. Jose Silva]
Yeah. I mean, that's I guess that's where we're heading or, or that's how Europe is heading, trying to preserve organ and we have done it for kidneys, for other organs? Why not the prostate, I mean, I'll definitely, I think that's, that's what's coming ahead.

Might be NanoKnife might be something else who knows what's going to happen. But it's exciting, I guess, that this field is evolving.

[Dr. Amit Patel]
I just want to say, I think, you know, Ranko put it best when he said that if we can take a patient that may have a clinically significant cancer and treat that lesion and make it a clinically insignificant cancer where we're just following them on, like we do with our active surveillance patients and we bring them down into a low risk category.

I think that's really what one of the sort of benefits of focal ablation is as we're reducing their risk. And if we have a therapy that has high efficacy, and a therapy that has low treatment side effects. and then thirdly, a treatment that allows you to have additional treatments. Doesn't take anything off the table. That's really the ideal focal ablation treatment.

(8) Future of NanoKnife Ablation in Prostate Cancer

[Dr. Jose Silva]
And do you guys see this, being stretched to higher grade cancers? Like group 3 group 4 maybe?

[Dr. Amit Patel]
I think if it does, it's going to have to be studied. you know, it'd have to be done under protocol and certainly, maybe in some extreme cases, but, I think it, it should be studied.

[Dr. Jose Silva]
But do you think it's a matter of technology or is it just a disease that is going to be throughout the prostate, even though you have a few biopsies that most likely it's already throughout the entire prostate.

[Dr. Ranko Miocinovic]
I think that one of the issues with high-risk disease is in certain cases you already have up to 30% chance that you'll have diseases beyond the prostate gland, whether it's lymph nodes or SVs or whatever. And, um, I don't think that those guys are cured by focal ablation of the gland only.

I think in a lot of those patients, you need very aggressive approach. That's a prostatectomy with lymph resection. Followed up by salvage or adjuvant external beam radiation therapy, and you're doing everything to stop this disease in its tracks while it's in the pelvis, local regional disease.

So, maybe this will play a role. Uh, if you have some kind of a combination of therapies, that would, treat localized locally advanced disease, but for right now, I think our, our focus is really just in these patients who clearly have just, you know Cleveland stage two or less, PSA less than 15, intermediate risk of, consisting of three plus four or four plus three.

And the other criteria is that if they have a PSA, above 15, then the PSA density should be less than 0.15. These are just some of the criteria from the study that we're using, to include patients.

[Dr. Jose Silva]
So you’re including patients more than 10 PSA, more than 10 then?

[Dr. Ranko Miocinovic]
Yeah. Yes.

[Dr. Jose Silva]
Okay. And that's regardless of the, I mean, if it's a 75, regardless of the age?

[Dr. Ranko Miocinovic]
Yes. I think that, uh, we know what PSA means. I mean, PSA is a marker that we all use, but it's not a perfect marker as you know. And so I think with this advent of MRI, and us knowing what the gland looks like now, much more accurate, you know, measurements of the gland size. I think that we have a better understanding in that patient population with elevated PSA, what we're dealing with. And so I think it's fine, if you have a guy who has an 86 gram prostate that has PSA of 10 or 12, his PSA density will be appropriate. And I think in that case, it won't make a difference whether that PSA's that high or not.

[Dr. Jose Silva]
And how long do you think is going to take for the AUA to add this to the guidelines? I mean, as a first line therapy, five years?

[Dr. Ranko Miocinovic]
So first and foremost, this is a, I just want to mention this. This technology is approved for all solid tumors. So, it's out there. You can use it. It doesn't have the specification for prostate cancer yet. That's what we're trying to do with the FDA with our Angiodynamics partners.

And, I think once we get this approved and it does have indication for prostate cancer and people, uh, engage in using it more, and we have a little bit more data, on these outcomes, I think, I'm hoping that it gets incorporated sooner rather than later, because it is very sound option in my opinion.

[Dr. Jose Silva]
And definitely, I mean, I'm not doing radical prostatectomy. I see a lot of prostate cancer. And then I just send it to the people if they want radiation, or they want a surgery, but people are looking for something like this. And sadly, most patients, I always say most patients will be candidates for this.

Cause there, group 2 one side of the prostate minimal DCs. And then you're submitting them to something more and more drastic. Even now with robotics is a prettier surgery, but still, the outcomes are more or less the same.

[Dr. Amit Patel]
Yeah, I agree. I, you said, sadly, I don't know if you said sadly because you're thinking that we're going to put our surgeons out of business, but you know, Ranko and I do a lot of prostate cancer surgery but I think, for us as urologists, you know, a majority of us are really looking to find the best option for our patients, and really cause we might be those patients at some point.

And so, I think it will never eliminate surgery fully, cause I think there are going to be candidates for surgery that are higher risk. But I think this is something that is up and coming and we're very excited about it.

[Dr. Jose Silva]
Good. So, thanks for being here with us at Backtable. I hope in a couple of years or one year, two years, we'll talk again about this, about your results and experience, and the followup on those patients. Um, uh, hopefully they'll be good.

[Dr. Amit Patel]
We would love to come back, Jose. Thank you.

Podcast Contributors

Dr. Amit Patel

Dr. Amit Patel is the chairman of the urology department at Duly Health and Care in Chicago.

Dr. Ranko Miocinovic

Dr. Ranko Miocinovic is a practicing urologist with Duly Health and Care's integrated oncology program in Chicago.

Cite This Podcast

BackTable, LLC (Producer). (2022, February 9). Ep. 30 – Minimally Invasive Focal Therapy for Prostate Cancer [Audio podcast]. Retrieved from https://www.backtable.com

Disclaimer: The Materials available on BackTable.com are for informational and educational purposes only and are not a substitute for the professional judgment of a healthcare professional in diagnosing and treating patients. The opinions expressed by participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.