Ep. 552 Dosimetry University Part I: Treatment Planning with Dr. Tyler Sandow and Dr. Nima Kokabi

[Music] This week on the Vactable Podcast. We have to remember this is a from start to finish, it's from like the pathway of Y90. It's about a hundred thousand dollar treatment. It's not a cheap treatment, right? So you have to have certain standards and aim for certain outcomes, right? Particularly if you're doing a segmental treatment, the goal should be to compete with a relation, a surgical resection. Anything short of complete response is a failed treatment. You have to go out of the retreat. And there's always a failure rate for every treatment, right? But you cannot just be so happy, go lucky about it, that I will treat and we'll see what happens. And a lot of those centers, particularly the OBS, they don't even do a post-window to those symmetry. So you're completing the dart, which is concerning to me. [Music] Hey everybody, welcome to Vactable 190 to Symmetry University. I'm Coby Krishnasami. I'm an interventional radiologist, I'm an interventional oncologist at the University of Alberta, Birmingham. I have two amazing guests with me today, Nima Kokabi and Tyler Sandau. Nima, you want to introduce yourself and tell me what practice you're in? What kind of practice you're in? I'm Nima Kokabi. I am at the University of North Carolina Chapel Hill. I am the Director of Intergrational and College, EM Vice-Surf Clinic, or Research for the Department of Radiology. And excited to be here. Now welcome. Tyler Sandau, interventional radiologist, interventional oncologist at Oshner Health, which is a multi-specialty clinic, kind of along the clinic model. I guess we've joked about it, private dynamics. I'm not an academic guide, I don't have as many fun titles as Nima does, or as you do, Coby. Since we are filmed, I do hope that they catch my beautiful, my beautiful reflection in this podcast. Well, I appreciate that. Real quick, special shout out to some of our colleagues around the country in prior practice, Austin, Burjua, Prisbeck, and Michael Bratzza for helping us put together the agenda for today. Nima, you're an academic, tell you already said you're in private dynamics and I'm in academics as well. So we like to think that we move forward, we're democratizing Y90 for the rest, for the country in the world and figuring out how we can better collaborate between academics and prior practice. So, anyway, with that further ado, let's get started. Do you both have IR clinics? We do. Yes. Do you both have multi-disciplinary tumor boards and/or multi-disciplinary clinics? We have both. So we have many multi-disciplinary tumor boards, one from a metastatic colorectal to a liver-specific tumor board, to an upper GI tumor board, to obviously, you know, other ones, chest, GU. We do not have integrated multi-disciplinary clinics as much as we would love to in a multi-specialty clinic model where we have many different campuses or many different hospitals. You can't just stack people at everyone. And so we do have a central IR clinic that most of our patients get filtered through and then we have two smaller IR clinics out in the community as well. We actually have a multi-disciplinary tumor board. We have multiple multi-disciplinary tumor boards for different indications, actually compared to MRE where you and I were both one of the biggest advantages I've seen at UNC as the multi-disciplinary clinic that we have for liver cancer. So we get to see the patients at the same visit as hepatologists and medical oncologists, which I think is great for optimizing patient care and expediting it. Yeah, I agree. And that's what we do as well. We actually have a HCC and colorectal multi-declinics. For us, it's not as involved in colorectal multi-declinic. We are in the tumor board and then we're starting in the rounder group and multi-declinics. So for us, it's just, you know, making the pace faster effectively, getting the patient from tumor board or initial entry into the UAB system to the entreatment. And so that's kind of the way we look at it. And I think all of us are in practices where people come from far distances to see us. It makes a huge difference having those multi-declinics because for me, an average person in North Carolina in terms of commute to come to Chapel Hill is two to three hours, if not longer, actually. And we're going to talk about hopefully some of those approaches to reduce the time to treatment and care for the patient. I think we can reduce their time or the number of visits. That's another way to get there. If I could interject real quick, I do think multi-disciplinary clinics are wonderful. And I think in a perfect world, we would all do that. But I think at large institutions like Yalls, and we're pretty large as well, it makes sense. And it should probably be because you can have more face to face interaction with young colleges and see, or surgical oncologists or hepatologists or transplacer, whoever is seeing the patient, there could be more timely interactions and engagement. That may not be feasible for people in private practice or people in practice as not as large as Yalls. And so I think another consideration to try to help improve the time to treatment or the communication might be to increase the engagement with your referring clinicians. So we want him, and as I've got always given him a shout out every time we talk about this, is he responds to messages probably within 10 seconds of getting them. And our texts were always available via phone for phone calls and anything like that. I think the more you engage with your referring provider, so people that don't have the multi-disciplinary clinic option available to him, the more you engage with your referring providers, the more you're readily available, the more likely you are to improve in a scenario where you may not have the option to have a multi-disciplinary clinic. Tell their point is very well taken. My phone is on 24 hours a day, seven days a week, whether I'm in the country out of the country, I respond whether and I'm not advocating that everybody has to do that, but that is the way that I approach it. I think what you guys also do that is also very beneficial for your patients, is you actively put them on the schedule for mapping and treatment very fast. - Great. - Yes. We don't schedule our treatments until after the mapping, right? Because the mapping does as a diagnostic study, but we do try to roll that in as quickly as possible. And we have schedulers dedicated to getting our Y90 patients on the scheduler's quickest possible. I am going to test you on this 24/7 availability. I'll call you at 3 a.m. this morning. - Deal. - And a little bit. - I don't wake up to text message. - I'll call you. - Well, you ready? - Yes, okay. - So average time from clinic visit to or multi-disciplinary tumor board discussion to mapping for you. - Okay, so the way it works for us, great question, and it was not always good, right? So we'll talk about this in a little bit. Our volume is we do north of 300 Y90 treatments, individual treatments a year. And trying to coordinate all that is a masterpiece. And so our coordinators do a wonderful job on that end. When a patient gets reviewed in our liver conference, and let's say they have HCC and they decide that they need Y90. The first person that needs to initiate that conversation is the referring provider, right? They don't need to call from our coordinator saying that you have HCC, and you need to come to IAR clinic to talk about a Y90. The person that has rapport with the patient should be the one communicating that. So we have that established at our system. Our hepatologist or oncologist or whoever it may be, will then send a message to our system in the clock starts right there. From that point, our lag time to get patients in clinic is same week. So we've improved on that. One has done an incredible job with our APPs and our schedulers and our group as a whole to get patients in same week. So they get seen in clinic same week. The time to booking on the schedule for most of us. Some of us only do certain types of Y90 case. Some of the more complex stuff is about one week. So they get clinic same week. One week later is a mapping. And then it our time to put them on the schedule for after mapping is somewhere between two to three weeks. Okay. For treatment. For treatment. Okay. Who sees the patients in clinic for you guys? So it's in a perfect world. It's our IAR physicians. Right now we are short staffed. We won't have this problem in August anymore. But the APPs, unless they're specific communications that need to be to be related to the patient. So right now it's our APPs only because we have to cover all of the clinics and all of the hospitals that are associated with Oshnaa footprint. We have to have boots on the ground and we can't put them in clinic. So once we get the three new IARs that I was telling you about this morning, we're going to be able to see everybody in clinic as quickly as possible. Because I think that is one of the reason you get to see them earlier than usual because you're utilizing your APPs greatly to that end. For us, we see them about one to two weeks after the referral has been made in the tumor board in terms of the liver, the rectiliracular, if you have any sort. And then after that the scheduling depends on if you want to use resin or glass. If you want to use glass, we do them separately, meaning do the mapping just like what Tyler said. And do the treatment afterwards. After the mapping schedule for the treatment for resin, we actually do order map treatment. We generally, depending on our schedule, for example for myself, I do the mapping on a Monday treatment on a Tuesday, two weeks out from today. I see them in clinic just to give our pre-certification people enough time to get the insurance approval. So I'm not. 98% of the time anecdotally, you will go according to plan and you get to treat the patient. But there will be times that you may have to cancel the treatment. But overall, it's worked really nicely in terms of expediting care for those patients. - Yeah, that's a great point. You brought a great point. The pre-certification to get patient, you have to get insurance approval for a lot of these, right? That Medicare is very easy to get approval for, but for some of these private insurers, they have a two week turnaround to approval. And so like you said, that two week gap is it should not go unnoticed, right? So sometimes you might see the patient in clinic, but you might have to wait two weeks before you get the mapping and/or the treatment. - So that's a great point. We looked back at our data. We found that our HEC patients in particular, non-MATs, but HEC patients were not getting denials. So we scheduled clinic and mapping back to back as quickly as possible, and then scheduled a treatment a little bit farther out to account for that insurance authorization piece of it. So our goal is treatment within four weeks of clinic. Doesn't really always work out that way, but that's what we tried to do. - Actually, even with the order of mouth treat, we haven't had any issues with denial. - Okay. - And I know we're going to see. - Anything? - Anything. - Oh, well. - Okay. - Or anything. - And we'll talk a little bit later as we discussed this morning about a single session why 90 going straight to treatment for certain cases. Even those, and I was surprised when we started it. - I thought for sure, some insurance companies are gonna push back on that, but and I know you've done some single sessions as well. I haven't had any issues with insurance. - I think it depends on which treat. And I think it all depends on who's looking at it and how focused they are when they're paying attention, right? HCC, if you look at all, so actually I love arguing, I love doing the peer-to-peer stuff because it gives me an opportunity to assess who I'm talking to, right? So you might be dealing with a pizza, the friologist or a pizza rheumatologist or a neuroophthalmologist who's denying your request to do by 90 for somebody with a metastatic colorectal cancer, where it's actually indicated in their policy. So I've actually looked at a lot of their policies and some of it, they highlight specific things, right? Like if it's HCC, it's an easy pass through. It just needs to be appropriately documented that it doesn't meet criteria for ablation or resection or it's not an ablatable candidate. So you have to make sure that you document well in your chart and that you're probably not having issues because when you are submitting your client pre-cert, when you're submitting it, you're submitting it with the appropriate documentation to say, doesn't meet criteria for any of these other indications therefore why 90 is the indicated treatment. Now sometimes, like if you're treating like a gastric met or an RCC met or breast cancer or breast, they will give you shit. I mean, and it's reasonable, I understand where they're coming from, right? You gotta keep the lights on and to their, in their eyes, it's considered experimental. But I do think patients do strive to benefit, or do stand to benefit from these treatments. And so I'm all about arguing peer to peer for these. - Well, I have a lung met on the schedule for a couple of weeks and that's exactly the route that I had to go and it's a four centimeter lesion in the dome that I think I could adequately ablate and the patient didn't want resection or was not a resection candidate. And so what else are we gonna offer, right? And that was the exact conversation and it got through peer to peer to peer point. So anyway, I wanna get back to a little bit of symmetry stuff that is the reason where the three of us are here and I know we're all very passionate about it. So glass versus resin, what's your both of your splits? What tumor types are you treating? Primary versus meds. - So we are basically a hundred percent glass. We've been that way probably for about seven years, six years. The majority of our practice, we are a transplant center. So we do have a lot of inflow associated with transplant and that being HCC as the primary driver. Most recently we've expanded one of our multi-disciplinary conferences to metastatic colorectal. Our involvement in that metastatic colorectal conference has been, there's been awesome. We actually run the conference through the imaging review with our surgical oncologists and oncologists on board. So we actually do a fair amount of metastatic colorectal now. We do a lot of neuroendocrine, but for those patients, those are primarily tastes. And so I will say we're probably 80% HCC, more 75% HCC with another, you know, 5% being clean, geo maybe 20% metastatic colorectal. Our metastatic disease. - Metastatic disease, okay. So mine is a little bit more of a historic context and UNI's work really the childhood of the MRE. So preflex those, for me, it was a very clear split. Anything HCC or segmental I was using glass, anything multifocal, and many practices around the country, actually they still pack it is that way. So anything multifocal or low bar particularly metastatic setting, they would use resin. So and that's how we were at MRE if you remember. And then because of some involvement, I had in research projects with resin when flex came out. I started to, and I had the concerns that many people have with the day of calibration resin at all, too many particles, not hot enough, you could get stasis, incomplete treatment, et cetera, et cetera. Even though some data has been published on that, but not much in the United States at least. So I have the same concern. So once flex came out, I started using it in a clinical trial setting and then I realized, and at that time it was only two and three day pre-couts available for the scouts that if you remember. I started using and I actually realized that I'm not getting any stasis, I'm getting good results. So I started using it more. In Atlanta when I was at MRE, it was still about, maybe at the end of it it was 60% resin, 40% glass for me. When I got to North Carolina, this whole issue of how far the patients travel from and the catchment area that we have, it really made it more conducive for me to use resin for the fact that I bring them, I do the mapping, they stay overnight at a hotel or somewhere close by and I treat them the next day. And that is purely why I'm using more and more resin. On a practice level, we are about 50, 50 glass and resin, but for myself I'm close to 100% resin now because of the whole efficiency and convenience factor. - Sure, yeah. - And it's ACC and METs. - ACC and METs. - Yeah, we're about 75, 25 hundred practice from a practice standpoint. A lot of ACC, 25 glass, sorry, good question. Glass resin. A lot of ACC, some clangio, we've said to see a lot of advanced clangio and then our METs were growing our METs side of the practice. So, co-rectal, some neuroendocrine and then random like long METs, things like that. So, that's kind of where we are. But I think six and seven day pre-cal to your point, we're at five day pre-cal, six and seven are coming. I think we're very excited about that. So, that'll be nice to see when we have access to that. - Decymetry guidelines documents. Decymetry apps. Healthful, not helpful. People have to use them. - I think it's great for guidance, right? Like I think, so there's, you know, Riyadh put one out for glass and they've updated it again. - And that's one just came out, right? - Yes, right. And then, so the most recent one for HCC was in 2022 and they gave you different guidelines for different scenarios that you might encounter, right? There might be a Ravlo back to me, RAD segment, attack to me might be multifocal, where you're talking about. And then, you know, other things where you're doing bilobar, metastatic disease, where you're talking about dose to normal. I think those are great for people that don't do this routinely where it's not on the back, I'm always thinking about these kind of things. I don't actually need, feel like I need to go back and reference them. But I think it's, those are, it's a great document. Whenever we tell people, you know, how you should practice, follow what's published, right? And that's the dose symmetry guidelines that are established there. I think it's very helpful in EMA. I think y'all are working on one for resin as well. - We are. - And so I think that gives people good, good reference points, especially when you're not doing it all the time or enough to where it's just, you can flip back to it in the back of your mind. - Training is coming out of, yeah, out of fellowship, right? I mean, 100% out of residency. So I think, and what I like about, I think they're incredibly important. There's a resin one that was published at GlassOne for HCC that Tyler mentioned. - Rich one's a little bit on the old set. - Oh, there it is. - So that's why we are updating it. And it was encompassing both Metz and Primary. And it was all with the day of calibration. And we'll talk about how things have changed. The point and hopefully by the end of this podcast, what we will get through is the approach, the different devices, obviously. - In terms of dosimetry, so you have to know the different thresholds, how to plan, et cetera. But what I love about the Glass consensus guideline that for the HCC and even for the Metz that they publish, they have very strong emphasis on treatment intent and not losing sight of that because it really dictates how you approach it from a dosimetry standpoint. I think historically, a lot of us have probably over-treated a lot of metastatic patients because of the fact that we would not be satisfied until we see no residual disease. But we have to kind of train ourselves to think more like a radiation oncologist for those palliative cases that disease control is actually a win in those cases. You don't have to kill the patient in the process of killing the tumor, so to speak. And that's why I think those consensus guidance could be very valuable in terms of, particularly for the less experienced centers and the Chinese to kind of keep compartmentalized the five scenarios that they have. I think it's a very nicely done approach. So I think they're important. - It's not that long ago that we were just doing 120 gray mired into the right little bit of liver. - For everybody. - We're 100, 100? - Yeah, we're BSA for everybody. - For BSA for everybody. - I mean, this was, you know what, not even 10 years ago we were doing this, right? And so really, there's been a lot of evolution in dosimetry apps. - Yeah. - And a dapper is kind of sunset, it's not available on. you can. - You can't get it on. - You can't get any more. - That's still have it. - Yeah. - I don't delete it if you have it. - Don't do it if you have it. - Yeah. - I use the Cancer One Nide app a lot. Still, I know that the glass estimates on the Cancer One Nide app are not accurate anymore. The estimates are for sphere activity and-- - Armin Mahavash from MD Anderson is the owner of cancer. He designed the cancer one night, yeah. From my discussion with him, they're updating it for the calibration. The updated calibration for glass and also making it available on Android. 'Cause for a while it was Android compatible as well and then it wasn't anymore. So I use that one. I think there again, Tyler's point. It's good to have it, particularly if you don't have access to other means of dosimetry. It's freely available. Is it the end all be all? No. - It's a tool. - Yeah, it's a tool, right? Hopefully for confirmatory measures, at least that. Okay, I'm giving this much activity to this volume of a segment or a lobe and we'll get into particle distribution and density based on what is published out there for both glass and resin. Am I giving adequate coverage? By giving adequate dose. So again, one tool in the toolbox. - Yeah. - And I think definitely helpful on the resin side. On the outside, here's in the TWA in the spreadsheet. Are you actively looking at particle count? Does the app help you? - So I will say this, and we're probably going to disagree on the particle count and coverage thing at some point down the road. So I'm not as well as this. - I'm just delaying the conversation. - I know, I can tell. We can bring the elephant in the room. The, so I don't use the app as much. I haven't found much of a need for it because of the way my practice is structured. And I think the TWA worksheet, which, for the majority of what we're doing, we're talking about unique compartment, merdo symmetry, which is the most simplest form of dosimetry that is, it's, I think BSA is very simple, but it's very inaccurate. I think merdo is probably the one that gives you a fair amount of accuracy, and it's the most simple to you. - For radseg. - For radseg. And also, I mean, - I'm segmental. - Sort of segmental. And wikings, yes. - I'm sure we're going to get down the partition, the partition game as well. Merdo symmetry is very simple to use. And so the TWA worksheet gives you that kind of information. We use simplicity, which is, it allows us to kind of calculate all that stuff. - And that. - Sure, dosimetry software platform. - Yes. - Right. So that allows us to get the dose and just do simple unique compartment dosimetry that way. Otherwise, I'd be using the TWA, before we use simplicity, we use the TWA worksheet. - And then you may use, man, I also use media as well as the all my contouring and luncheons and all that thing. How do you feel about them? - I'm a little bit biased towards them because I got to use it as a resident when I was doing dosimetry research. We had it at Emory Back in 2011, 2012. So I like it, it has changed significantly in terms of becoming easy to use with the AI components that it has, it contours the lungs and the liver automatically once you open a spec CT. The biggest difference between the two softwares and we've done courses on these in terms of those symmetry and many conferences, including SIO, at least according to FDA, you are not allowed to calculate the TWA ratio. You can calculate the TWA ratio, but you cannot go further than that if you wanna use partition model dosimetry. - On the MAA spec. - On the MAA spec because the point FDA makes and I could be a point of discussion here as well, is that MAA is not an accurate circuit for Y90. So they don't want to basically approve a dosimetry software to be used for partition model dosimetry using the MAA data. But that's the best we have at this point. I agree with you on those points too. And I will say, MIM is coming very long way in the last five years. We used to use MIM too. I mean, it honestly five years ago kind of sucked. - It would take an hour to do one single planning, but it's not that way anymore. - Five minutes. - Yeah, the AI components have really advanced and I'm very impressed with the software. - So, coffee remembers, we had about 20 nuclear medicine physicians at MRE. - They were doing all our dosimetry. I get to know like, I'm touring all of them. - It would take a long time. And I realized that we don't have as big of a nuclear medicine division. So I had to teach myself how to do it. And I was scared. Initially I was like, oh my goodness, this is gonna take me half an hour and an hour to do. But with the whole MIM protégé and the AI component, literally for particularly the simpler stuff like a segmental treatment, so we do quite a number of less than five minutes today. - Yeah. And we need to understand, y'all are in academics, we're in private academics. You might have a little bit more time to do this. But people that are trying to read studies and between trying to do cases, you gotta make it quick and easy. Somebody's gotta be able to reproduce this and run on it. And so rather than mentally harness all the things associated with the great software, we gotta make it quick and easy. - I will say though that when I'm using MIM and dosing a case, it's usually a separate at night. So it's not, it's not, it's not, it's not. - And not our pointness. So now that both software have improved significantly in my opinion, both, under other blow-summitry software, but both software, by both I mean simplicity and MIM, there's actually a economic components as well to it in the private practice and even in academics that if you do the work, you might as well get paid for it. So you can actually get reimbursed for the pre-treatment and you can get reimbursed for the post-wine anti-dose symmetry confirmation, which we can talk about later as well. - But you have to document, right? - You have to make sure your coders know to bill for it. - Yeah, it's true. - So they're required, there's an educational component. - Yes. - So I wanna skip the post-dose symmetry part, we'll come back to that pre-dose symmetry or MAA dosimetry. What values, what numbers do you absolutely want to have to dose a case? - Depends. - Sigmantal treatment, I think for either, and this is what I kind of borrowed over the years from glass data. I think Partisham model, those symmetry from Sigmantal is an overkill. I think Shamar is gonna probably call me after he sees this as a give me his opinion, but, 'cause what are we trying to achieve? We're trying to kill that segment, right? So you don't need to become too fancy about it at all. I want my tumor to get this, those, and my non-tumorals portion of the segment to get this, so I use single compartment dose symmetry, whether I would do glass or resin for segment tech to me. Where I think Partisham model really excels is when we are talking about those color rectangles and the multifocal cases that really, there is no downstaging to surgical resection for most of them. What they have, they've been treated with three, four lives of chemotherapy, before they come across your clinic. You really wanna make sure that you don't tip them into liver to count the compensation or failure. - To it. - But that's where you need Partition, right? - I think so. - Well, yeah. - Go ahead. - We haven't explained Partition yet. - We haven't explained, so we're jumping to get a little bit of that. - Before you jump down that road. So I think I do wanna ask a question about Partition, because we should talk about that next. I think when we're doing a rad sec, the things that I care about are perfused volume and lung shunt fraction, right? So I calculate, 'cause that's my perfused volume is going to be the area that I treat. And so I use a comb being CT to calculate that. Some people actually just map out a segment and they say, they do anatomical dose symmetry, where they just say, I'm going to treat segment eight, so I'm gonna calculate the volume of segment eight. We do what's more functional, so we'll do a comb being CT from the area we intend to treat. And we measure that volume based on the comb being CT, and that becomes the volume that we enter when we're gonna order a specific activity to target a specific dose. And I agree with you on the component of looking at the TDN ratio in a rad sec is overkill on the pre-end, but we do have to recognize that there is preferential flow to hypervascular lesions in a rad sec that will play a role when you think about how you're going to dose your rad sec. And I think there will be nuances to that that we can dive down there, but I don't want to poopoo the TDN, but also don't want to neglect it either. So partition. - So do you calculate TDN for rad sec? - No, okay. - But do I recognize that it happens, yes? And so if I have a threshold dose for the way that I like to do it, and I like to do sub-segment tech to me, so my profuse volumes are kind of around the tune of 150 ml for the most part. If you are treating a 5 centimeter tumor and 150 ml worth of volume, that 5 centimeter tumor occupies a very large portion of that. So if I dose it 400, and I want the tumor to get an ablative dose, the tumor is probably only going to get a dose of 400 gray. Now if I dose it at 600, the tumor will get closer to 600 or 800, but if the tumor is two centimeters and the profuse volume is 100, a two centimeter tumor, assuming it's a sphere is about four ml worth of volume, so 100 divided by four. So your angiostone to tumor volume ratio, which I think will play a role in down the road, is 25 to one. So there's going to be preferential flow up to a certain point to the tumor, right? So the tumor will absorb more, but a sponge can only hold so much water at some point. The yield is low, but there will be preferential flow before you become completely embalic to the tumor. And so 400 gray in that territory might be, and actually have a higher TDN ratio. And even if it's three to one or two to one, the tumor's getting, if you go 400 gray to that profuse territory, the tumor might be actually receiving a dose of 1,200 or 800 gray. Right. And so I think those kind of things matter. I don't actually, I think we go in there like you said, when you think about radsec, I think about a blade of intent of a territory. If it dies, it dies. But I think you also say that there will be preferential flow to where the tumor is up to a point. - I want to clarify one thing. And so I want to go back to, and this goes back to razor, right? And so razor, the tumor got 1,000 plus gray. Because of the TNR in the perfuse segment, right? They didn't give a thousand-- That was a very smaller tumor. They were smaller to-- agreed. I think that was all three-- They were all less than three, which is the majority of what legacy was. Two-thirds of the tumors in legacy were less than three centimeters. But the perfused volume dose was 584, or closer to 600, right? And so the tumors-- so they were treating smaller tumors. And then their perfused territories were smaller. And but the tumor dose was more close to a thousand gray. And so the tumor volume to perfused volume ratio comes into play. And then the TNR comes into play as well. And to your point, when I'm dosing a tumor and the tumor occupies the majority of the segment that I'm dosing, I'm escalating my dose on purpose to that point, right? Because if I get 400 gray straight to tumors, the tumors just get to get 400 gray. It's not going to get a thousand gray. Correct. So I don't spend a lot of time-- So let's make this re-simplify this. I don't spend time thinking about this shit. That takes way too much mental energy. I just assume that if I raise my floor-- not just a 400, but if I raise my floor to 600 or 800, whatever-- I'm getting more statistical probability of being lethal in that tumor. And so that's how I approach it. But let's talk about partition, because I think partition is important for people to understand as since we brought it up. So I like to call me CT volume measurement. I think it makes it-- I think it's definitely more accurate than the volume measurement on anatomical scans. Because we go always with a preconceived notion, oh, this is going to be a chip shot. It's going to be a single feeder, corner of segment 6. And we always often get surprised that even the simplest location may not actually have the simplest angiosomes. Part of it is number one goal is kill tumor. Number two goal is spare normal liver, especially with the blade of doses. So if I can work to get more selective and spare 200 season normal liver, I will do that 100 times. Yes, we always will. So I want to come back to partition. I'm sorry, I don't mean to cut off that conversation. I want to hand on a couple of other topics before we get there. Andrographic vendor. And are you using andrographic targeting software? So we have Siemens for our sweets. And you've seen our shot. We like it because we're in South Louisiana. And Popeyes poisoning is a real thing. So we got bigger patients. They have bow jangles. Yeah, yeah. We got-- I mean, hey, look, man. We also got-- we got bourbon street, which keeps us in business too. But you can do wide combing CTs, the swing on a combing CT. So we can actually have the patients arms down by their side. Is this the artist or the iconoplatform? The artist. Yeah. And so we can do combing CTs a lot more comfortably and efficiently. And that makes our practice run smoother. So our mappings don't take quite as long as we don't have to worry about arms down, arms up, arms down, arms up. I like Phillips. I used it in fellowship. I would associate it as more of like an iPhone. It's more functionally simple to use. Siemens, I think you can do a lot of fun things, but you have to know how to dive down that road. I don't use the Inbo guide. The way I approach it-- and we'll probably talk about this down the road-- is that I like to do proximal or low bar combing CTs to assume complete tumor coverage. And then I'll do combing CTs from there. I intend to treat. And I make sure that I have the same tumor coverage that I did on the low bar that I do in the more distal combing CTs to see complete tumor coverage. I use-- Siemens as well, we have Siemens. And it's artists. And we have patients on the bigger side of things as well. And we do a lot of radial or go to radial. And we should probably talk about that at one point of what is your go to axis and why. I use Inbo guide all the time. I usually do a combing CT proximal from a common hepatic or proper hepatic. Get the comb-- I did use the Inbo guide to see what the feeders are. And then when I select it, I will confirm again with a second comb-- a more selective combing CT and go from there. And I was telling Tyler this morning, sometimes I say this is definitely not true what the software is suggesting, but more often than not, the software proves me wrong. And there's data that supports that. There is data that the targeting geographic software will catch things that our eyes will not catch. I think where I struggle a little bit with targeting software, it's a great confirmatory tool. I don't like to leave it on live because a lot of my cases are multi-dose cases. And then you have four different vessels that are criss-crossing on top of each other and it can figure out where I'm going. I don't use a live option either. I do like it for confirmation, but I don't use a live option. You like to stay in the room for your comb beams? Yes. Right? Just shield. Big shield. And inject to your comb beams. Well, so no, no. So I will say this. I don't-- let's not say we always hand inject. OK, all right. So that Enema brings up a great point, too, which I think this is why we all get good results. You do proximal comb beams. I think you have to do proximal comb beams with a power injector to show what the tumor is looking like. And I think one of the keys to success is making sure you do an incredible mapping. And so you emphasize this as well. A power injection proximal combing, whether it be in the proper hepatic artery or in a low bar branch, you can see how the tumors covered by the feeding vessels. So we do power injection comb beams proximally. As you get farther out and you're doing your selective comb beam CTs, which you're going to use to calculate your myriad or your perfused volume doses, you don't want reflux. So now power injection can become problematic if you were refluxing the vessel when it comes time to calculate those doses. So I actually prefer to inject those by hand so that I'm not refluxing. And I think a lot of the older injectors, you had a minimum cutoff of how low you could go. My current injector I can go down to 0.2.3. Yeah, CC is a second. So sometimes I will just power inject in those cases. But that you ever hand inject? Every once in a while. I have never hand inject this. I learned it from Tyler. Yeah. That's where I got it. Because we did a lot of PAEs at Emory. And we were using 0.3. And they actually worked nicely without any reflux. So I was always used to for segmental, 0.3 to 0.5 ML for whatever the-- Usually it's at 13. Hey, look, I think there's nothing wrong with power injecting. I would just say that my experience with power injecting a sprocket, especially with doing these 150 sub 100 ML perfused volumes, is that there will be reflux if you're not controlling for it. Even at point 2 or point 1. And so these forearms, they can squeeze some contrast. I can't beat a power injector. But I can also control-- I'm watching in real time what's happening as things are flowing. And so I think it's fine to do it both ways. I think you just need to understand the limitations to both. I'm getting a slightly higher radiation test because I'm in the room doing the Cumbium CT. But you're shielding your-- I am-- oh, yeah, I'm feeling it. I'm not dumb enough to just go-- You're not stop-- Prado letting me get me. Well, I mean, but you have the ceiling shield and the T side shield in addition to wearing lead, right? So you're actively shielding like I would in CT flora for a long time. Correct. And I will say we do a fair amount of Cumbium CT. Because again, you're doing a low bar proximal powers, and then you're doing more distal confirmatory. And our radiation doses are on the low end. I mean, we routinely stay below one grade during a pretty complex map. So in the interest of being controversial, since we have Tyler here-- Do you think people that don't do Cumbium CT or don't have Cumbium CT should be doing Y9? I will say there are limitations. There are some people that don't have it available. There are some sites that you just can't do it. And you might be the only person that can do Y9 in your state, and you may not have it. And so without saying that, I don't want to say it's malpractice. I would say if you have it available and you're not using it, that's a problem. Because I think that I have seen so many things and you highlighted this with Inbo guide, right? There are so many times where you would think it's going to be one feeding vessel, and it winds up being something entirely different. And so Cumbium CT is an integral part of the mapping. And it is part of the diagnostic workup. And if you have that diagnostic tool available, the patient needs to benefit from you using that diagnostic tool to treat them appropriately. Not everybody has access to that. And so that's where sometimes spec CT, you might actually have to use some of these other confirmatory things down the road. So I don't want to say that it is substandard care if you have it readily available and you don't use it. And I think everyone that does Y9 should do everything possible to make sure that they do have access to Cumbium CT. And I think that you should fight with your institutions or your hospitals to provide this kind of thing. I don't think it's fair for the patient to go get a Y90, expecting the same result that you guys provide when there's somebody else, somewhere else that's not doing Cumbium CT. Like everyone deserves to have the best possible outcome for them. And I think that you're asking the right question. And I'm trying not to just be a total. I think the conversation is also different for talking about a peripheral three centimeter lesion in segment six versus an eight centimeter central lesion, right? Like that conversation is sure. - Totally different. - Sure. - Can you get away with the segment six lesion without Cumbium and use a spec CT as a confirmatory? Probably, but I don't know that I would ever advocate for a second. - Why? - I don't think you can, you can honestly tell me that you got complete tumor recovery. Or you can. - Totally. I don't think you can give me the same assurance that I can give you with Cumbium CT. - 100%. - But you didn't have it. - Yeah, if you didn't have it. But if you have it and you're not using it, yeah, there's a problem there. - I don't know how many institutions don't actually have it. If a machine is 10 years or younger, they usually have it. Unless we were talking about OBLs. - Right, I'm a little bit ill. - Concern that I have with OBLs and people are gonna hate me for saying this, is that those are the ones that actually don't do spec CT either. - Yeah. - So they have no combing. They don't do spec CT and they want to do Y90. How and collectively between the three of us, we probably do close to. 5 to 600 Y90s a year. Okay. How many times you get humbled by do you goals to a case and you say I guarantee you it's one vessel and you go in and you're totally missing a rear missing half of it I was once a week. Yes, exactly. It happens every other day to me. Yeah. So that's my concern that maybe not everybody should be doing it, you know, so yes, of course the goal of this podcast one of the goal is to make sure as you said to spread the like spread that everybody does it, but Not everybody can do open heart surgery. Well, and you know agreed and I will say this is not just opinion, right? There is data that supports you will find additional feeders on cumium CT that you don't visualize on DSA, right? That that is well No, we all know that there's data that supports you can use anatomic or you can use anatomic volumes, but they're inaccurate compared to perfused volumes. How many times can you go into a case? Oh, this is going to come off the segment eight and it comes off of segment four or say, We're right. So you can't predict these things. This is why we all I'm sure we all advocate mapping first before you decide what you're going to do, right? Always map and then maybe the patient's not. You know, this is a we have to remember this is a from start to finish from like the pathway of Y90. Particularly if you're doing a segmental treatment, the goal should be to compete with Ablation of surgical resection. You have to go out of retreat and there's always a failure rate for every treatment, right? But you cannot just be so happy, go lucky about it that oh, yeah. Well treat them. We'll see what happens and a lot of those centers Partigarity, OBS they don't even do a post-wind eye to those symmetry. So you're completing the dark. Yeah, which is concerning to me. I agree And I think you bring up with open heart surgery. You bring up a very valid statement. What you got to do is you got it You got to try to optimize everything as best you can for the patient and You'll be surprised at the number of sites that don't have combing CT. So we've had We've had other sites and not Oshner affiliated, but we wound up getting referrals from patients that had either you know incomplete responses or failed responses and for what should have been very simple stuff and They we go in and we review cases and we have to say like hey look well We missed the vessel and look you know there was no combing to confirm that and so You have to raise the bar if you're going to compete in this level if you're going to compete with surgeons You're going to compete with or SBRC. Yes or radoncs Rather getting great response. I mean we can Denied all we want I work with a lot of good radoncs and we are very collaborative Take good results. Yeah. So if we keep going down this road of oh, yeah Let's simplify it and this is the point of what this podcast we want to simplify it as much as possible, but there has to be Minimum standard for this treatment that this is not a taste that you just go and hope for the best and you bring them back and do a second time at a third time and you could do that, but that shouldn't be the The the norm. Yeah, that's not the aim. Yes Well, and I know me by no means and I'm am I saying that you know, you don't need to have combing to do a radiation segment I'm a one I couldn't be everybody, you know Pre on the M.A. study on the mapping right and then I have a very low threshold to combing on my delivery if I think looks off I don't like it the profusion is changed if I'm using a balloon catheter or something pressure directed I will recombine and I'll do it during the delivery and it is standard in my practice So I think it brings up a whole can so kind of worms But you know the question is always how do you democratize and if you don't have combing and you don't have spec'd I think there's their dishes obviously. I mean they're they're going to be problems And I think you're going to get humbled we we combing on our delivers to from the area we tend to treat prove that everything's the same combing CT parameters injection rates spin rates. What do you guys typically do? So we do power injection proximally It is two for 22. It's a five second spin with a six second injection or a six second x-ray delay Okay, so it's 11 seconds total with a rate of two times 11 22 22 22 I do that from the low bar. I do it from a proximal left proximal right And then obviously when I get further out I use a forearm strength for for no reflex control. Okay, so we do five second Spin eight second delay so it will left 13 second and I have a three two one point five rule If I'm doing common hepatic three four 39 if I'm doing a right low bar two for 26 left low bar depending on the size either one for 13 or 1.5 for 20 and then for segmental usually 0.5 for six or seven and I think we're all aligned Proximal cone beam CT is imperative to success. I think so. Yeah first. Yeah, first step. I was there were you getting yeah Is for people that go hunting first you wind up getting burned and then all of a sudden agree It takes so much time to come back and retrace your steps If you do that proximal cone beam CT first you wind up seeing everything the way that you need to see it And so if you you say catheter as a wrong vest or you were you were burned you have a reference point to go back to You got to do it first and sometimes you see other lesions that agree because there is delay And this happens to all of us that the MR that was discussing the tumor board is two months old So by the time you get to see the patient on your table that MR is three months old I had a case two weeks ago that she had a very large tumor in the dome of the liver We did the combing proximal and then I realized there were two tie not tiny one and a half two centimeter lesions in the corner of segment two and three One was obscured by the heart motion on the MRI and the other one was right next to the gastric wall So none of them were visible on the MR that was a month old I had to bring her back to do the treatment for those as well So those are the things that you're not going to see if you don't do the proximal 100% agree my protocol I've phillips I can't even mention that earlier now, so I actually have access to dual phase scans So then I'm less worried about perfusional differences and changing my x-ray delay So my standard I got a base cat I try to get a base catheter out into the proper apatik and then I'll do two for 20 I have a five second extra delay five second spin and then that's my little bar and then I take my let off and I sit down at the station And I figure out where I'm going to go and I spend 10 minutes doing and it always pays dividends for me So I do that invariably pick my spots the one nuance for me is I will do a dsa at every location To inform my injection rate for the cone beam I do that very commonly if I'm not going to hand inject to your point The way how are injection dsa? I'll do a low volume power injection dsa So I to inform my cone beam so I'm not getting a bunch of reflux and then I can get an angle I think that's reasonable. Yeah, and I look I inject so I've worked my way proximal to distal right so you start celiac then you go commoner proper then you go low bar then you go Segmental then you go sub-segmental I think you have to work or even if it's an a to your posterior division on the right and you work your way proximal to distal and you do DSAs at each step. Sure, especially if you're going to be doing a lot of them or you're going to be You're going to be treating a patient two or three weeks later and you're not going to remember where you were it informs you For how you made it to the spot that you need to treat from yeah Well, and it's it's not uncommon for me in my practice. I don't know how you both feel but in in a complex lesion large lesion multiple rad sex I could do 10 cone beams in a single mapping and that's that's not my text like the big fun to me But I don't know how you book. What's your average number of cone beams? Oh five to six. I just six. Yeah Very common right four to five And we have I have no qualms about it To me I do as many of them as as I need I don't Because it becomes easy to set up as you said we'd be put the arm next to the patient We're doing great deal for the most part But it doesn't matter where there's radio or growing as long as the arm is next to the patient The setup is very easy. It's basically essentially similar to a DSA It's just a little bit longer, but it's almost the same. Yeah, well in your cone beam is again paramount to success Right, so I have a 90 90 arm position or I can leave the arms up and it's relatively comfortable for patients It used some of my mappings out of general as well. I don't know if you both use in general anesthesia for mappings ever We do it So ashore has a we have some hospital policies if you have sleep apnea anesthesia has to be involved in care And so if anesthesia so a lot of people have sleep apnea especially when pop-pop poisoning is prevalent in your in your region So a lot of people have sleep apnea So if anesthesia has to be involved I need breath holes and so so if we have to use general anesthesia patients wind up needing needing to be intubated so that we can do breath holes Well, it's helpful right? I mean if they're moderately sedated and they can't fall instructions You're gonna get crappy code bit. Yeah, oh see I yell at patients. I yell I sternal rub I pinch toenails I um we wake up okay, and so this is a very important point that if you are using anesthesia Ask for GA Don't do proper fall because you're gonna be You're gonna become frustrated I'm gonna become frustrated most importantly you're gonna get garbage Information that is not gonna be helpful for your treatment planning. Yeah, my patients are either awake Minimally if at all a rouseable or yeah, yeah, or or GA some full full paralysis. Sorry. Yeah, yeah, I totally agree with that Okay, so access sites you said radial. I'm a femoral I'm a hundred percent femoral. I can do radial I don't our rooms are not well set up for it every time I've ever done radial the arm has been out you know, in a cross-like position. That's very annoying. If you're trying to do a comb beam like that, it's damn near impossible, right? And so you, I'm sure, have navigated, you've navigated those problems easily, and I'd love to hear how you do it. But we do femoral. We've had no issues with femoral. It's our texts are well equipped to set that up rather than have to have them be very good at radial and femoral. We just femoral makes the most sense for us. - Yeah, well, and the other thing I would say, and I learned this when we were together at Emory, and we did a lot more radial at Emory, big patients, lesions far to the right side, keeping the left arm down, which is what we often do for radial. Sometimes you just can't get the couldn't be all the way over there, and that's-- - Well, with CMAS, you can, there is actually, so I'm a huge radial fan. We do the Sinai Ray, 'cause I learned from Zach Berkuer, partner at Emory who was trained at Sinai. Our next to the patient, I particularly like it because by order of map treat, I bring them like the next day. I can use the radial again. I don't have to worry about a closure device that I've put in, I don't have to go to the other side. I think it has a lot of advantages. In terms of stability, particularly if you wanna do segmental or sub-segmental treatment, I like to use the MG1 catheter, which is, I take that to ride hepatic, left hepatic. - It's a trumel glide cath. - It's a trumel glide cath version of a Sarah or Jackie radial. - Yeah. - No issues reacting to the left radial artery next day. - I've never had an issue. I've had a radial artery thrombosis months after the initial Y90, and it was partially thrombosis, we could still access it, but the patient was completely asymptomatic because we always check for bar bow and all of that. But no issues so far. - I think there's a lot of misconception around glide catheters, three different types, right? There's a four-french double braid, there's a five-french single braid, that is a complete noodle, and there's a five-french double braid, which the MG1 comes in a five-french double braid. - That's the one that I thought all of those details. - That's just, I was just, just give me an MG1 for good things. Some people just gotta make it even harder. - Well, that's a single braid. - Well, you know what I mean? - It just doesn't work. So anyway, side note, add that grass, I'm sorry. (upbeat music) Thank you guys so much for tuning in. If you haven't already, please be sure to subscribe, follow, and rate the show. Let us know how we're doing and what we can do to improve it. We work really hard at making this a valuable resource for you and we want to continue to do that. So give us your feedback. Lastly, tell a colleague about the show. We think they'll like it. 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