 So, let's go ahead and get the afternoon program started. We'll try and keep on schedule. Two more speakers and then we'll break for our patient presentation after that. So, to kick off the afternoon section, Dr. George Shade is a faculty member in our Department of Urology, Urology Surgeon, and he's giving a talk, Histotrypsia Novel Ultrasound-Based Treatment for Kidney Cancer. Awesome. Thank you. Well, welcome everybody. I get to start off so hopefully nobody falls asleep from eating lunch. And so, I'll try to keep it interesting. And so, just to kind of... I wasn't quite sure what to cover. This is my first time at this event, and I do a lot of work with members of the Applied Physics Lab working on this technology called Histotrypsia, which I'll talk about. And so, I thought, as a kind of a lead-in, I would talk a little bit about just very briefly on image-guided therapy, which I didn't see in the program, because that's sort of, in a sense, what I'm trying to accomplish. And then we'll introduce everyone to Histotrypsia, and then kind of talk about some of the stuff we've done, and ultimately what we hope to achieve. And so, I'll kind of quickly glance over this. You guys all saw some of these numbers earlier, today, in Dr. Tikoti's first few slides. And then, as we've touched on kind of extensively that for patients who have small orenal masses, particularly those that are less than four centimeters, partial nephrectomy is the gold standard, and it's very efficacious for the majority of patients with stage 1A to Z, so those less than four or some of your tumors. But obviously, it's still invasive, and whether that's a robotic or laparoscopic procedure. And so, there's been a long interest in, quote-unquote, image-guided therapy. And kidney cancer is really one of the ideal tumors for that, and unlike, for example, the prostate, we see tumors very easily on pretty much all standard imaging modalities, and so you kind of see the full gamut there, ranging from ultrasound, CT, MRI. And so, because of this, people have looked at it, and obviously, if you're going to try to invent something new or less invasive, you obviously want to make it as good or hopefully even better than traditional therapies, in this case partial nephrectomy, while reducing the morbidity by preventing collateral damage. And in the current state, at least in the U.S., the kind of the mainstay of focal therapies are cryotherapy, so freezing the tumor, or radiofrequency ablation, which essentially emits radio waves to cook tissue. And without question, at this point, cryotherapy is thought to be the preferred modality. And there's other techniques being evaluated, including microwave therapy, essentially putting little electrodes onto microwaves, something called electroporation, which is actually a non-thermal technique where you essentially put two electrodes in a tumor and pass current through it to try to make holes in the cells and kill them that way, and then something called HIFU, which is high-intensity focused ultrasound, and that's somewhat related to what I'm going to be talking about. And then kind of the current iteration, it's actually a laparoscopic probe where essentially you would put it on the tumor and then use ultrasound to heat the tissue. And in all cases, all these techniques are still invasive. They require percutaneous approaches, so sticking needles through the skin, or in some cases laparoscopic. And so although the goal is to be less invasive than a partial, that they're still invasive. And this is sort of a really nice cartoon I found sort of depicting what percutaneous cryotherapy looks like in the current state. And so essentially patients under either conscious sedation, sometimes just with local, or in some cases general, depending on how comfortable it is for the patient, essentially we'll go to a radiology room with a CT scanner and using a combination of ultrasound and CT guidance attempt to pass multiple needles into the kidney as depicted there, both in the cartoon and then in the picture. And so compared to open surgery or even robotic surgery, it's less invasive, but obviously you end up with a bunch of holes in your back and it's still uncomfortable. And in some cases requires general anesthesia. And historically for sure these approaches whether cryo or RFA, while relatively effective, part nearly as effective as partial nephrectomy which is a gold standard. And so this table is from the AUA guidelines that are now about I think five or six years old. And you can see that with cryotherapy and RFA roughly the five year survival, recurrence free survival rate is about 90% compared to about 98% for partial and LPN is laparoscopic partial and is an open partial nephrectomy. However, more recent studies have suggested that as our experience has improved and the technology has improved, that this gap is narrowing and in some cases may even be very similar at least at three years. However, when looking at severe complications the rates are actually very similar to partial nephrectomy. And so at least with these technologies they're sort of failing to achieve what the ultimate goal is to be as effective or more effective in a way that results in less complications. And some of the shortfalls that contribute, obviously one, we're poking things into the kidneys that contributes to some of the complications such as bleeding. But one of the major limitations is size. And so with the exception of the electroporation I mentioned all of these rely on thermal diffusion. And so in the case of cryotherapy you stick probes in and you're trying to free something and you create an ice ball that expands and RFA you're sort of doing the opposite. You poke something and you're having heat expand out to cook the tissue that way. And so that heat can only spread so far from your probe. And so for tumors greater than four centimeters in particular it's just hard to reliably get that ice ball or heat or char I guess to spread consistently throughout the tumor. And that's what I was trying to show kind of in those little cartoons between small tumors you can imagine it's pretty easy to uniformly kill maybe a one and a half centimeter tumor but if you have a four or five centimeter tumor that becomes difficult. And then the other aspect is where the tumor is located. And so essentially located tumors are more difficult to treat and I'll kind of go over this in the next slide and associate with increased recurrence rates and complications. And so the reason for that is if you kind of look at the kidney here there's just a lot going on in the kidney. And so the cartoon on the left is trying to depict that you see the cortex and medulla which are sort of the meat, the filter aspect of the kidney. And then the collecting system is where the urine collects as well as obviously the blood vessels that bring blood in via the arteries and the veins that take it out. And those latter things that's really kind of the business part of the kidney and that's where the main set of complications or the dreaded complications can occur. And that's also what contributes to the difficulties of effectively treating centrally located tumors. And so if you kind of imagine this lower pole tumor here it's well away from the big blood vessels that get well away from the collecting system. So you can imagine you could probably freeze or cook this tumor without having to worry about damaging where the urine collects. And there's this idea of heat sinking and so blood, if you're freezing something brings warm blood in and so you're sort of melting your ice ball as it tries to form. In the case of cooking something it's cooler than your temperature you're trying to achieve so it's sucking heat out. And so if you're in the periphery where you don't have any big blood vessels you don't have to worry about that. But when you're centrally located you have big blood vessels that either insert your ice or suck heat out of your char. And then likewise you have to be worried about either cooking or freezing that collecting system and if you were to kind of cook the whole thing and ultimately create a hole you could end up having urine leaking out of the kidney from the damage. And so because of these issues it's hard to respectively treat centrally located tumors with any of the existing technologies which really limits some of the patients that we can treat with these approaches. And additionally a major limitation is the ability to monitor treatment in real time. And so thermal changes historically are very difficult to monitor with sort of standard imaging techniques. Sometimes you can see the formation of bubbles in the tissue if you're cooking it on ultrasound. In the case of Crow you can see the ice ball forming but you can't really see beyond the edge of the ice ball. And so it's hard to really know if you're effectively destroying the cells or not. And so that leads to sort of this question in real time where you adequately treating the tumor. Then as I mentioned it's invasive and so this is just another picture in the case of laparoscopic cryo. And so depending where the tumors are sometimes you just can't safely pass an edle into the tumor and so you have to for instance flip the colon or the bowel out of it laparoscopically and then bring in your trocarism. This is what the ice ball looks like if you're curious. And then this is that laparoscopic hyphu transducer I was mentioning which currently is under a series of studies. And ultimately I'm not sure how much it brings to the table because you still have to do laparoscopy and if you have to do that that's one of my opinion. And so the question is what can we do better? And so with that that's sort of my segue into histotrypsy and so well what is histotrypsy? Obviously it has a funny name and I mentioned hyphu earlier and it is a form of focused ultrasound and that's what this is trying to convey here this figure. So this is an ultrasound transducer with sort of a bold shape and so amidst the ultrasound waves from kind of all different angles and they converge on a single point and that effectively increases the intensity from where the surface is just about the same as an imaging transducer but as all that energy converges it increases intensity as you get closer to that focus. And is anybody here a treatment for a kidney stone? So what's let the trypsy? So breaking a kidney stone with a stone trypsy is fracturing and so that's how we got the name of histotrypsy and so essentially we're trying to mechanically destroy tissue and so I'll kind of briefly go over hyphu but in the case of histotrypsy we're trying to non-thermally and mechanically destroy tissue with ultrasound. And so in comparison to the thermal hyphu that I mentioned before there's a few kind of key differences and so the first is it's much higher intensity and so I was kind of going over this before so for diagnostic ultrasound the typical intensity that you would feel is roughly about 1 watt per centimeter squared and so if you imagine a small little circle you're basically passing the equivalent of 1 watt of energy through that little circle. With thermal hyphu it's roughly 100-fold higher so 100 I guess to 1,000-fold higher and so up to 2,000 watts per centimeter squared and histotrypsy is essentially a whole other order of magnitude higher than that. And we deliver the energy in a pulsed fashion so with thermal hyphu normally it's a wave that's just kind of on either permanently or for like 2 or 3 seconds at a time so you're delivering enough energy that you start to vibrate the tissue and that leads to heating of the tissue. But with our intensities if we pulsed for that long we would heat very quickly and thermally destroy it and probably a whole lot more and so by delivering short pulses of energy we're able to induce the effect but then have the transducer off long enough that heat doesn't build up and so the result is a mechanical effect and I'll kind of go over that a little bit more in a second and because it's mechanical I want the tissue to coagulate it and cause necrosis that way we're actually fractionating or pulling the tissue apart and so this is sort of what it looks like if you really wanted to know that the key is that it's dependent on bubbles and so that's what this is trying to convey there's a few different ways of performing histotrypsy it was initially developed at Michigan about 15 years ago or so which is where I did my training as a resident and actually came here because UW was the only other place doing histotrypsy and invented this technique called boiling histotrypsy about four or five years later and so the reason why it's called boiling histotrypsy is just the mechanism of forming the bubble and so essentially what we do is we administer high-intensity pulses, like I said for about, on average, about 5 to 10 milliseconds and that results in very rapid heating due to the amplitude and kind of the form of the ultrasound ways we're administering and so essentially at the focus you create a bubble and you've boiled the tissue and you create a bubble and then the pulses interact with that bubble and that creates forces that destroy the tissue and so the advantage of our technique compared to the other ones is that the kind of the engineering and the power of your machine needed to heat something isn't as great as relying purely on sort of pressures and things of that nature to form a bubble that way and so it's much easier to adapt existing technologies compared to some of the other mechanisms in the way of getting this technology into patients quicker and so just to kind of touch on again the way this works our hypothesis right now is that it employs something called acoustic founding and this is something that has been well known to the people for a long time it's actually how immunifiers work and so you basically pass energy into like an air fluid interface and you basically send little droplets out in the case of a humidifier, moistens the air in the case of tissue and so this is actually from live or not kidney but this is the idea and so you basically at that air, water or air tissue interface you're essentially hitting and destroying and liquefying the tissue and just forming these jets and so those jets then in turn further destroy the tissue around it and liquefy it and like I said this happens in the order of just a few milliseconds and so obviously I'm talking about kidney cancer we're trying to develop this technology as a non-invasive treatment for kidney cancer and so that's one of the advantages of ultrasound as many of you know you've had an ultrasound all it requires is a probe on your skin and so hopefully no pokes and no incisions and our hypothesis is that this will be effective where other technologies have failed because we believe it solves some of the limitations I mentioned and so it's non-invasive as I mentioned and as you'll see it offers real time guidance on ultrasound which is a big advantage compared to having to be a CT machine or an MRI machine to administer the treatment and it's non-thermal as I mentioned and so you don't have to worry about the heat-sinking effects as I alluded to earlier and because it's mechanical we think it's a lot more precise because just like you rely on that heat to diffuse you don't have complete control of how far it diffuses and so you're going to get a little bit of thermal spread that may kill other tissue and so using this technology we started off by triggering tissue like in tanks and things like that but we've been able to use kind of transition to large animal models and for kidney the pig is the best model because anatomically it's similar, it's a similar size and kind of has the same challenges as far as if you're trying to kind of push ultrasound energy through an abominable wall or some ribs for instance into the kidney and so we traded about 12 kidneys so far in pigs under general anesthesia and as I mentioned it's transcutaneous and so essentially we get the pig ready put a water bath on the pig because you need something to transmit the sound into the tissue and then put a transducer in that water and then we can move it to wherever we're targeting and this is our current iteration of the transducer and so you can see that actually to get all that energy you don't need a very big transducer and so you see a Sharpie marker for reference so the current iteration of the transducer is about four inches in diameter and so overall not very big and as I mentioned this was all done under ultrasound guidance and so this is what it looks like in real time and so the great thing about bubbles is that bubbles are air and air doesn't transmit sound and so it appears as bright areas on ultrasound in real time and in the lab we don't have as nice imagers as we would have clinically and so in a clinical scenario this picture would be much nicer than what we can get in the lab just to the cost of a clinical grade imager and so right off the bat you can see that from this we know exactly where we're treating in real time and so you get that feedback of are we hitting the tumor and so in this case it's just a normal kidney which is kind of outlined in red just to help draw your eyes to it and the other nice thing is that the treatment produces a change in the tissue and so if we were to kind of watch this video in real time long enough where you kind of went back and forth through the tissue eventually you would see that the scatter that you get with ultrasound dissipates and so you basically create a black hole in the tissue and as you'll see there's very good correlation between that ultrasound picture and what you see when you look at that kidney right after you take it, right after the treatment and that also correlates very well to what you see on histology and so basically we get feedback both on the efficacy as well and studies have shown that the degree of how dark this tissue is correlates very strongly with the degree of how well you liquefy the tissue you can almost appreciate that here on this ultrasound too and that kind of at the very edge here you see it's a little bit darker than the main kidney and that kind of correlates here where you sort of have only partial treatment at the edge and so I think that kind of confirms that first part that you really get a lot of feedback with this technique compared to other capabilities and as I mentioned it's very precise and so in this case we intentionally treated two lesions right next to each other trying to leave something like a millimeter or two millimeters of tissue and you can see that we're able to effectively leave a bridge of intact tissue and this is without any motion tracking or gating and so just like in people in pigs, kidneys move about two or three centimeters with each breath and so even without having to stop pulses for when the pig's breathing or kind of tip the transducer to follow the kidney we were still able to very cleanly create two lesions right next to each other and you can see that the transition from basically completely liquefied tissue right there's basically no architecture it just looks like red jello or something I don't know in the center of this lesion it's very clean compared to treated and normal here and we've kind of further evaluated that with electron microscopy which is significantly higher power as far as how close you can look at the tissue and what we found is that that margin from normal to dead is 20 microns and so it's in some cases smaller than a complete cell or about the size of two red blood cells for instance and this is again those same pigs so no respiratory gating or anything like that and so it's remarkably precise and so potentially that would help us treat close to critical structures like the collecting system or a blood vessel and in some ways it may not even be because another very cool thing about histotripsy because it's mechanical the mechanical characteristics of a tissue are very important as far as how the tissue responds and there's clearly a very clear relationship in the kidney for which tissues are most sensitive and which are more resistant and so luckily for us the collecting system is one of the more resistant types of tissue as is the renal capsule and so there's sort of this little layer of collagen on the outside of the kidney and tumors which is very tough and so in theory that would help with bleeding because you could sort of treat the tumor and the edge of the kidney with a little bit of reckless abandon and hopefully preserve that capsule to minimize the risk of bleeding or something like that and further blood vessels are even more resistant and you'll see later there's actually in the next slide no two slides in some slides you can actually see a blood vessel intact surrounded by dead tissue and so potentially that would help prevent bleeding you can break up a normal kidney but what about cancer and so working with Dr. Wiesinski actually who's going to talk next we've been able to procure pieces of human tumors following nephrectomies and so far we've been able to gather 8 to 10 or so it's kind of logistically challenging sometimes it just happens often it ends up being like the end of the day and then it's hard to effectively treat but what we found is that similar to sort of the gradation of normal tissue we see similar kind of things with different types of tumors and conveniently it looks like most tumors are actually more sensitive than normal kidney which obviously is great if you're trying to spare the normal structure that hopefully would help facilitate that and so that's what this is kind of showing here you kind of see sort of that gradation and this is all ex vivo tissue and dead tissue is not nearly as sensitive as living tissue and some things out of the body decomposition happens very quickly and you start to get gas in that tissue and that gas blocks the ultrasound energy but you can see that for kind of the two most common types of kidney cancer it looks like at least ex vivo they're about 10 times more sensitive at least as far as complete liquefying of the tissue compared to a normal kidney and so obviously that's an encouraging thing and so based on that as we'll talk about we've done some in vivo studies kind of touch on the kind of things we've done to try to optimize this and how fast is it and so what we found is that higher intensity in shorter pulses delivered at a quicker rate are more tissue selective and result in quicker ablation and so to sort of explain that maybe an easier way to understand is that the key thing for heating is how long the transducer is on and so normally we try to have it on less than 1% of the time but if we shorten those pulses to 1 millisecond pulse we might only be able to fire the transducer one time per second to have 1% of the time on but if we shorten those pulses to 1 millisecond we can deliver 10 pulses and so in the end the amount of time the transducer is on is the same and so you have a relatively speaking the same amount of heating to the surrounding tissues and so this was what I was talking about before where essentially you see three little intact blood vessels surrounded by completely destroyed tissue and so this is we've been able to tailor this further where we've been able to sort of preserve the scaffolding of the normal kidney where we in some ways you could think of not necessarily for cancer patients but perhaps it would be a role for patients with liver failure or kidney failure or something like that you could try to wipe out the diseased normal and figure out a way of repopulating with healthy cells and so we haven't had a chance to look into that but it's an exciting possibility and then getting at how fast is this in just those 12 kidneys we're able to achieve an ablation rate of about 27 cc's per hour and just as a frame of reference that 3.5 centimeter spherical tumor is about 22.5 centimeter so roughly we could treat something like a 4 centimeter tumor in about an hour we think and so overall it's pretty quick and because it's non-thermal where we want to be limited by size either so potentially we'd be able to treat even larger tumors as long as we felt it was safe in that nature and so as I mentioned we've looked at this in vivo and kidney cancer as well and so we've been working in a small animal model which is a rat essentially that develops kidney cancer spontaneously so it's not with the cell line these are otherwise normal animals they have normal immune systems and things of that nature which is really advantageous for some of the other work we've been doing and essentially just like in the pigs we treat them with their histrity through the skin and so we've just been trying to target about half the tumor because when you're doing this you want to approve that you hit what you wanted to hit and so we haven't treated the whole tumors yet and this is all done under ultrasound guidance and we've recovered the animals up to 8 weeks and in general it's very well tolerated they don't require any pain medicine after the first day and so what does it look like? well essentially very similar to what I showed you now those pigs were an acute study meaning we treated where it's easy they've all healed for some time and so the borders aren't quite as distinct because it's starting to heal and contract around but you can still see this is sort of our plan treatment here and you can still see that sort of demarcation between normal viable tumor and what we've liquefied and then it starts to evolve over the course of 2 weeks where you can see that really contracting down you're starting to see sort of a little bit of a scar forming at the periphery and we've done this in normal kidney as well essentially the lesions evolve very similarly and end up looking very similar which is what you see here and so at 8 weeks it looks like pretty much everything's resorbed and you're left just with a very small scar at the center and you can see again we tried to treat about 50% of this tumor and so you can see kind of compared to its neighbor here where it's really kind of contracted down around that cavity and really shrunken size and it looks essentially identical to the scar you would see in the normal kidney it would be beneficial from a post-treatment standpoint one of the problems with cryotherapy and RFA is you all often end up with this sort of funny looking lesion around the kidney that's very difficult to determine if there's any viable cancer in there or not because they often look very similar on a scan and so the hope would be that this would look either this has a little area that doesn't get any of that contrast on the scan and so hopefully it would be easier to follow and this is just sort of what it looks like grossly so again this is the same tumor compared to untreated tumor just demonstrating how things really contract around it by just eight weeks and one of the things that we've noticed as well as in some other models is that histotrypsy produces a lot of inflammation afterwards and so I just tried to point that out here basically if you see lots of little blue dots on a slide those are inflammatory cells and so we see that at seven days we see it still at eight weeks at the periphery of the scar right here so that really got us thinking about this idea of immunomodulation as you've heard a couple of times already today and in the Haifu world this is probably the hottest area of research people are really looking at ways of trying to improve cancer therapies and the immune system is an obvious target and so these studies are actually in the prostate cancer model but sort of the same idea and so this just shows that if you essentially either gave a mouse a tumor and then either just cut it out with surgery you treated it with Haifu and then waited about two weeks and cut that tumor out this just shows the differences in the immune cells that it can harvest from the spleen and so in this case, CD8 positive T cells which Dr. Takoti had alluded to earlier and these are really sort of what we call the cytotoxic cells so these are the ones that ultimately lead to cell death and so you can see there is a significant rise and then when they looked at how these might survive after implanting the tumor what they found is that if you just gave a mouse a tumor and then cut it out they died much quicker compared to if you treated a small portion of the tumor survived or kind of recovered for two weeks then cut the tumor out essentially you're allowing that immune system to develop a response and create memory so this idea of auto vaccination and this has been sort of taken one step further in this case in the liver cancer model where essentially you treat one mouse as tumor you let things recover and you give T cells from the mouse process them and give those T cells to another animal with the same type of tumor essentially essentially it's what's called adoptive transfer so you're transferring immunity and what they've shown is that you can increase tumor regression which you see here decrease the rate of metastases and then ultimately improve survival and so it's obviously really exciting it's in a mouse and people said we've cured cancer in mice hundreds of times and it's always a lot harder in people but because of that when considered in the context of kidney cancer where there's multiple well-described immunologic aberrations and the setting where surgery doesn't seem to really impact those aberrations and obviously we heard about there's this well-defined role of immunotherapy and really got us thinking about what are the immunologic effects of our treatments and so we initially did this in short term and so this is just kind of very select graphs and so one of the things we looked at over the first 40 hours is can we see a signal in just the blood or the plasma and so what we found was that there's a near significant increase in a molecule called HMGB1 which is sort of a molecule that's in our cells and when you damage tissue it's sort of leaked out of the cells and stimulates the immune system it's sort of one of the very first events to trigger a response and kind of downstream of that is a cytokine coltina which is one of the on cytokines and what we see is that it seems to be a very rapid uptick in these molecules suggesting that there's at least that initial oomph you would need to cause an immune response and when we looked at the tumors at 40 hours with something called immunohistochemistry so essentially you're staying in the tissue with antibodies to look for specific types of cells or receptors we saw and I hope this conveys basically the amount of brown spots in the tissue we saw more C-date positive T-cells in the treated tumor at 40 hours so those are the killer T-cells essentially compared to sham so an animal that just had an ultrasound and not the histotropy but what's really interesting is that in the contralidal kidney we saw more of those C-date positive T-cells compared to the sham treated animal and so it seems like potentially since these animals get tumors on both sides that you may be able to create a response that's not only targeting what you're trying to kill with your direct treatment but we're seeing a signal on the other tumors as well and so based on that we started doing some more longer-term studies we'd hope to do more IHC but working with rats you're really limited and we've had a really hard time with antibodies so we had kind of switched to flow cytometry which is kind of a fancy way of counting cells and what we noticed was that although long-term when we look at the total number of all C-date positive T-cells we don't really see any differences when we look at specific subsets we have seen some significant differences and so the first type is what's called an effector memory T-cell and so these are cells that essentially have been turned on stimulated by their antigen and essentially are out there ready to sort of turn into active cells that would then mount a very rapid response against whatever their target is and we've seen this in the spleen as well as the tumor-draining lymph nodes and what's really interesting in the lymph nodes that I can I'll show you in the tumor is that these animals seem to be immunosuppressed as far as the number of effector memory cells in their tumor which is similar to human RCC and with the treatments we sort of return them to normal in some ways and as I mentioned we had hoped to assess the tumors with IHC and so we had to kind of change our protocol so we didn't have enough animals to achieve statistical significance but the trends are essentially the same so we would see in this spleen or the lymph nodes suggesting that we're impacting not just the tumor but as well as the other tissues as well and then as I mentioned we saw a signal in the contralateral kidney with the stains and so we looked at that as well and so whereas the left-hand curve is just a percent of a cell these are normalized to the control kidney and what you see is that if you treat normal kidney which is here you really get that significant response whether it's in the kidney you target or the contralateral but when you treat tumor not only do you get an effect in the kidney that you treated which is the ipsilateral but also that other kidney and so again it just sort of proves that it seems like we're impacting not just the local tumor environment but all around and so this suggests that there is this cancer specific change in the immune system but obviously it's too early to say it really has any impact on overall tumor biology or survival and so I have my cartoon it's similar to the others but I just chose this one because you can see I mentioned HMGV1 and so it just sort of points to this idea of kind of initiating cascade and ultimately leading to potentially T cell activation and development of memory and so in summary as I mentioned bullion histripsy offers a non-invasive way to precisely ablate tissue to be well tolerated in vivo it provides real time feedback and so hopefully that will improve our ablation outcomes it offers selective ablation as I mentioned and so hopefully this will help with preventing complications and preserving normal structures and it seems to at least on kind of a first pass produce significant immunologic changes that hopefully would lead to improved ablation outcomes both for patients who have just organ confined disease you can imagine if you're creating a strong immune response if you miss a few cells then hopefully the immune cell system would just kind of zap those up to improve your risk of recurrence but potentially there would be a role for metastatic patients as well and so because we're not limited to smaller tumors potentially instead of having a big kidney mass taken out when you have metastases perhaps we could just blast as much of that tumor as we can or maybe we blast a small portion wait a few weeks to turn on the immune system then do surgery develop a clinical prototype in the next few years we just had a big grant renewed by the NIH so we're hoping that by the end of that grant we'll have a clinical prototype we obviously need to evaluate more long-term oncologic control where we try to treat a whole tumor and kind of see how that tumor responds and then ultimately we'd like to assess how this impacts metastases and see if combining it with PD1 inhibitor one of the other checkpoint inhibitors would improve outcomes and obviously science is a team effort so I would just like to thank all my collaborators and I'm a little bit over on time but I'm happy to take some questions that's one of the questions we get because it's mechanical that concern in the ultrasound community is very low people get the same questions about thermal hypho initially because of the fact that you're hitting tissue hard enough there's still a mechanical effect of thermal hypho, are you somehow pushing cells into the blood or lymphatics or something like that it's a really difficult question because you're in an animal model because you'd have to have hundreds and hundreds of animals to really prove for sure and just because you proved it with a melanoma model does that apply to kidney cancer or colon cancer or whatever but in kind of small studies that were done when I was a resident the best we can tell it doesn't seem to improve or increase the risk of metastases in a kidney cancer model but the question is we don't know I mean yes because we're targeting the tumor how do you control it so the thing there is that's like an open space but in real life if I go back to that cartoon it's actually a controlled environment because in real life that's within the confines of a bubble that's within the organ and so it sort of has a backstop in real life it would because it wouldn't be like again this isn't a water bath there's just sort of an organ exposed and so it's splattering just to demonstrate the point but in real life it would be contained and we've seen that sometimes in a little as one pulse you can almost completely liquefy something and so obviously there is a theoretical risk that a few cells might break off or something like that but practically speaking with the repetitive nature it's very rare that you see any intact cells with multiple pulses and within your lesion so our transducers tend to be in the like one two megahertz strains that's the thinking obviously I was really focusing on local disease but absolutely we're working on this technology in liver as well so in those same pigs we treated the livers as well at least in pigs liver is more challenging than kidney it tends to move more than the kidney with each breath and they're just pigs are fatter there compared to over their kidneys unlike people and so it's more difficult to get the energy there but all being this potentially for liver tumors obviously kidney and then potentially metastases I just had a grant funded for prostate cancer so we're going to start to look at that as well the operating system the collecting system well right so I think so again based on the sort of the selective sensitivities our hypothesis is that we would be able to treat right up to that and assuming the tumors are more sensitive like we think we could sort of tailor the therapy to give enough pulses to the tumor and hopefully minimize the risk of damaging the collecting system or a blood vessel that was right there that's always the million dollar question yeah I think like I said we're hoping to have a clinical prototype by the end of this grant that was just funded so that'd be about five years and then from there you basically have to attest the device in animals to get FDA approval to try it in a human and then have a trial with HIFU being approved there is a chance that we would sort of have a workaround from the FDA standpoint again to people quicker without having to be quite as rigorous but we're expecting to have to do it all from scratch in which case you had probably be at least ten years from actually being approved and ready for primetime thank you