That's an excellent talk, Prasad. Very informative, very detailed, going through all the studies on the syrnastics and then the various non-invasive techniques. So here are some questions. One is, is Cytosponge commercially available for population screening in the U.S.? Could you discuss about IsoCheck, IsoGuard, which is commercially available in the U.S.? Yeah, I believe the Cytosponge is certainly commercially available by Medtronic. Like any other test, these are cell collection devices, and with the Cytosponge, the marker is Trufoil Factor 3. And I believe Medtronic has a process for training the hospital pathologist with processing the sample, staining the sample, and then interpreting the sample. So they don't provide a central lab where you can actually ship your samples to. So the analysis would have to be done at your own hospital. And I believe if you reach out to Medtronic, they might be willing to come out and train your pathologist and endoscopist as to how to obtain the sample, perform the test, and then send the sample to the local pathologist for interpretation. So that's number one. From IsoCheck, the test is actually called IsoGuard. And I believe it is. So it's a combination of IsoCheck, which is the balloon, which acquires the sample. And then IsoGuard is the platform, which is a methylated DNA marker platform. And I believe, again, you would have to reach out to the company, and they would have to come out and train your nurse or your investigator or your endoscopist to do the test. And then I believe they do have a central lab where you can ship these samples, and then the sample would come back as positive or negative. And then you would have to then decide on the next course of action. So if it's positive, then I think the endoscopy would be the next step to confirm or refute the diagnosis. And Dr. Hegman also mentions that IsoGuard, its affidavit DNA test has more than 90% sensitivity and specificity. Yes. Yes. Yes. And I think I alluded to that in the slide that I presented. There has been a single paper in translational science that has been published. And we await additional reports of its sensitivity and specificity. I believe the assay platform has certainly changed, and the balloon has also evolved. So we look forward to more data on its accuracy. So another question here, is there a difference between Watts3D before and after PPI treatment of esophagitis? Yeah, that's a great question. Maybe Prashanthi, you are aware of data, but I am not aware of any data that has looked at Watts3D before and after PPI. The only data that we have seen is, what is its incremental value beyond the Seattle protocol? I'm not aware of any either, whether it makes any difference before or after PPI for esophagitis. Then another question here is below the upper esophageal sphincter on biopsy. So I think they are talking about thoracic inlet patch. Patient has history of dysphagia, PPIs did not give any relief. So will you do cryo or coagulation? Yeah, I'm not sure that if there is no... I'm trying to understand the question. So if there is no dysplasia, I would certainly not treat. If the patient has dysphagia and you're not seeing any obstruction, luminal obstruction, I'm not sure that treatment would necessarily help. There has actually been a report in the literature where some of these inlet patches are acid producing and they lead to a globus phenomenon. I believe this trial was done in Germany where they actually did radiofrequency ablation or APC and eliminated these inlet patches. In those instances where you showed that there was acid production, the patient had globus or was symptomatic, and then you treat, it could help. I would only treat in those instances. So I would caution about this because a patient has globus and then have a thoracic inlet patch, and then you're doing an RFA in the proximal esophagus and the patient has much more pain than any globus. Something to handle with, like say when we do the ablation for high-grade dysplasia or so, low-grade dysplasia, the patients bear with that pain and they do not complain about it usually. Even when you do for non-dysplastic patients, they do complain of pain. When they're doing an ablation for high-grade dysplasia, they're thinking about it as an alternative for esophagectomy, so they'll go away with more. But for a patient with globus or so, I would be very hesitant. I know I'm aware of that study, but very hesitant about that. Absolutely. But is a thoracic inlet patch related to the dysplasia? Unless there is a stricture there, I would not suspect that to be a cause of dysplasia. Completely agree. Completely agree. So I think we have the questions addressed in the question and answer as well as the chat box too. So shall we break for lunch and meet again at 1230? Yeah, I think that sounds good to me. Another question, any factors that would influence biopsying the inlet patch? Yeah, I don't routinely biopsy an inlet patch, but if you see a visible abnormality, if you see nodularity, if you see luminal narrowing, in my 15 years, I've seen one cancer that has arisen from an inlet patch. So it's very rare, only in those instances, but I don't routinely biopsy that. Agree. I have seen only one patient with definitely a nodularity there, which showed high-grade dysplasia. So we removed it by an EMR and afterwards did like an ablation to get rid of the rest of the patch. Correct. Correct. One more question here, because at times they seem to be elevated than the surrounding mucosa. Agree. If you see a visible abnormality, definitely it should be removed. You should do an EMR if it is a flat surface. Another thing which can help is using a narrow band imaging to see if there are any visible abnormalities. Using a cap would also help you sort of look at that area, because in the upper esophagus, it's hard to stabilize the scope sometimes. And I will sometimes use a cap to, again, it goes back to our first talk, as you're pulling out, do take a look, particularly if the patient has upper esophageal symptoms.

non-invasive techniques

Cytosponge

IsoCheck

sensitivity

upper esophagus