19 Q&A with the Faculty 3

Introduction to Q&A Session

We have about 15 minutes for questions.

It can be about the things that the panelists spoke about during this session.

If you don't have questions about that, feel free to ask anything. I'm a urologist.

And just for the record, we do have long needles and we can reach those lesions if we know where they're at.

Antibiotic Prophylaxis for Transrectal Biopsies

I was wondering for the in OR trans rectal biopsies, what antibiotic prophylaxis are you using?

So I do use two because I've had two patients who've had infections that I had to admit.

So in a large volume group of patients that I've done.

But two because of that, I use the Cipro and IV gentamycin.

Good. And what prep are you using?

The prep is the same as a trans biopsy. You could use a fleet.

The fleets, yeah. Okay, thanks.

Elastic Registration on UroNav

You have a question? Go ahead. Yeah, I have a question about the UroNav.

Now, this elastic type adjustment, is it available or is it which ones look like that is more sensitive because it's adjust?

Well, the question is, is the elastic registration available on the UroNav?

And I actually don't know the answer to that because we use a beta system.

But I think they're out there, so you can ask them yourself.

But there's we do, I just want to reiterate that elastic registration is great, but it's not critical for a lot of things.

The rigid registration works extremely well in most cases.

But you can ask them yourself.

My understanding is that it is planned for deployment.

False Negatives in MRI-Targeted Biopsies

How often do you see a finding on the MRI that your it's a four or a five, you're certain this is or pretty certain this is a high grade or cancer and the biopsy results, targeted biopsy results come back as normal tissue?

This happens all the time.

It's routine, actually.

I mean, it's at least 20% of the time.

And so we do have an approach to that.

If it is truly a PI-RADS five, that is a 1.5 centimeter lesion that comes back negative.

We do sort of make an appeal that maybe there were something went wrong during the biopsy in terms of the registration, and that we would encourage a re-biopsy of that lesion.

And oftentimes that happens and it turns out we get a positive.

So we that really is the value to me of PI-RADS five is that it conveys a sense of urgency to the urologist in the first place.

And if the biopsy is negative, then it conveys that really we need to try again.

I don't feel that strongly about fours, but they're in there and certainly not threes because we admit that we don't have that same kind of positive predictive value for those lesions.

But that's that is certainly the case. Claire, Daniel, I'd throw four into that and say, I would like to, if an if it comes back negative from a PI-RADS four or five, you should repeat it.

And that's kind of what we do.

I think that's one of the main utility of the PI-RADS assessment system.

It gives you a sense of whether or not your finding is concordant with pathology.

So we have about a 10% negative rate for our assessment category five lesions.

And I think it's 20 to 30 for fours, maybe even a little higher.

So for fours, I think it's definitely worth considering whether or not you would wanna do a repeat biopsy for fives.

I would actually advocate for Pete's algorithm where they should go to in-bore targeted biopsy.

I don't think I would receive a very warm reception at my institution, but I could get them to repeat the image fusion biopsy.

And I think one of the other things is it really does help, if you look at the ultrasound features, a lot of times this is due to misregistration, and especially if there's a little bit of motion with the anterior lesions or the apical lesions, it can be difficult to accurately hit the target.

Yeah, so I mean, we've had a whole bunch of these that are we're just certain that these are clinically significant cancers and when the biopsy comes back normal prostate tissue, I just can't buy it.

I could buy if it came back granulomatous tissue or something like that.

But frankly, not every pathologist will they report it either as cancer Gleason score or normal.

They don't always report inflammation granulomas disease fibrosis.

So that's a problem.

And this is one of the things that we're getting straightened out with our own pathologists.

But there's no question that lesions are being missed with these MR targeted biopsies, even some pretty juicy ones.

And that is definitely true, and I view it very much as catch and release.

So in the sense that if there's a negative biopsy, there's an elevated PSA, it's a PI-RADS four lesion, you can put 'em back in the screening pool, they're still getting PSAs.

They're still under the care of a urologist.

And so the chance that something crazy is going to happen in the year is very very small.

It's a it is after all a slow growing tumor.

So some moderation in how positive you have to be every time has to be considered.

Mechanisms for Reviewing Pathology of Targeted Lesions

Yes. Quick question.

So I'm just, at your various institutions, do you have formal mechanism to review the for reviewing the pathology of the lesions you target?

Or is it people just individually on collect the cases they have and at some point a couple weeks later, try to see who got which biopsies.

Okay, so that's a great question.

Let me repeat that and we'll go down the line.

Maybe starting over here.

Do we have a at your institution, is there a formal mechanism for reviewing the targeted biopsies with radiology, with pathology, with urology?

Yes. So we have twice a month we sit down and look at all the biopsies that were done.

So every two weeks, we just have a planned meeting.

Do you look at all of them or just the ones that are sort of the misses or the interesting ones?

We look at all of them. So we just go to that's a lot of work.

But the normal, the ones that were positive, they just explain it's the urologists like, and it's a multidisciplinary conference, so it's nice to show, and it's actually a PR effort to show that MR works so well when it's shows up.

So we do two things.

One is a weekly multidisciplinary conference with urology radiation oncology and medical oncology in which four to five cases are reviewed, and all the pathology is carefully reviewed with a pathologist.

The other thing I do is I usually have a medical student do this, but every case is on a PowerPoint and all the lesions are demarcated on each slide.

And in the little notes section of PowerPoint, they put the results of the biopsy for that lesion, because again, we use the same annotation and we can build that up.

We don't review the pathology with the pathologist in those cases.

We accept the report, but we record that.

And then periodically, usually once a month, we go over those PowerPoints and see how we're doing.

Claire, Well, I've been doing this a long time, and to be honest, we don't have a standard format for review, which is really a big mistake.

I think we need to start doing that.

We do have a monthly multidisciplinary conference with the urologist, which is really generic to most urology cases.

It's not specific to the biopsy programs.

But I think what you're asking too is really, are we going to get to where breast biopsies are continually reviewed?

And I think that's where we do need to get to.

And certainly we're starting to do that and we're planning it, but we have not been doing it formally.

We do have a prospective IRB that we enroll every patient that's biopsied.

So they're in a database, and we have many of our researchers analyzing that data, and we're looking at the results, but we're not sitting down with the urologists and the pathologists, which I think really we must be doing like others.

So our urologists have basically sat us down with the pathologist to go over the whole mount cases to show us all the times we're wrong, but for our own humility.

But for the biopsies, actually, our bioengineers have a automatic database where they collect all this information.

It works so well that actually, I don't sit down with the urologist.

And I think, just like with what Claire was saying, that's probably an error on my part.

We're trying to set up an automated way to pull in the target.

We have a screen save of all the targets that goes to PACS to record what we were thinking and to collect that with the pathology data so that we could quickly go through the cases.

I think that can be tremendously useful to figure out what is it that makes a good positive target?

Yeah. So I think this is a really really important issue that we haven't focused on enough.

When we started out doing these fusion biopsies, I dunno, about a year and a half or so ago, with Daniel's help by the way, because the chairman of urology at our place came from his place and loved the service that Daniel was providing.

So we tried to duplicate it in some ways.

We got together with pathology and with the primary urologist and with the radiologists involved in this every couple of months.

And we weren't doing a lot of cases to review the ones, particularly the ones we were missing or the ones that were like really good.

Big wins for MRI, it's hard to find the time to do it.

And we were doing it at after five and people are not real anxious to stick around and it's time consuming to sit there and review the path results, look at the pathology, look at the radiology, look at the MRI review it with the urologist, figure out what went wrong.

And so we decided though we were doing more and more of these, and we needed to get other urologists knowledgeable about this, other radiologists knowledgeable about this.

So we decided to have a prostate tumor board meeting every other week that's in the middle of the day on Mondays following GU tumor board, which occurs every week.

And this hasn't worked real well either.

We can't get enough people there.

So we're now starting in January, we're gonna have, we're finding a time where we're gonna meet every other week with urology and pathology and go over every single case.

The problem is, the volume has gotten to the point where that gets, frankly, very difficult.

So hopefully, some of them will be real easy, but honestly, you cannot learn this stuff without sitting there as a team pathology, radiology, and urology, and carefully going over these cases.

You just will not learn it.

And I don't think it's sustainable if you don't continue to do that. It's my own opinion.

You know, what you say, Jeff, is totally true.

In our weekly conference, we report what our suspicion level was, and the pathologist gives their report, and we notice periodically that our results are not as good.

We're not finding the tumors or the routine TRUS is picking up the lesions, and that's when things go we look back at what we're doing in the biopsy suite and tweak things and check things, and sure enough, the following week things start looking better again.

So I think it's a continuous process.

There's no, yeah, there's no, like, you do it for X amount of time and you're done. Yeah, I mean, I feel so strongly about this based on my own experience with it that I would suggest you shouldn't even get into this business unless you're willing to invest the time as a group in getting together and reviewing these things together.

'cause it's just gonna get you into trouble if you don't. Yeah.

What we do is we have a planned meeting every Tuesday at five.

So we usually meet once a month.

25%. Yep. Okay.

Post-Placement Scan and Reimbursement

There's a written question here.

The question is, do all panelists perform post-placement scan with needle in place?

Do third party payer and Medicare re and it's a question about third party payer and Medicare reimbursing for MRI guided biopsy?

That's a good question. Yes.

The first question, I don't no longer, I do not no longer take the verification scan, but I did for a long time.

But it's nice if you're starting out that you know you're in the lesion, but now I don't, I just do three cores centrally within the lesion and one on each side, and that's all I do.

And it does the Medicare does pay for it.

We take a verification scan on all our target biopsies and Medicare does pay.

I'm gonna pretend that we do, I think it's about a 90% rate, but technically, yes.

Lower Size Limit for Biopsies

I have a question. Do you guys have a lower limit on the size that you'll biopsy?

Is it five millimeter?

Is it I mean, I saw the numbers are all talking about one centimeter greater than one and a half centimeter.

Is it a lower limit and you see something you

I'm seeing heads shaking? No, it's two or three millimeters. If it's PI-RADS three or four or five, we should repeat.

You should be able to get it. I mean, it sort of depends on which technique maybe you're using.

If you see something, we don't have a lower limit something you shoot something.

Yeah.

I mean, if you see something, say three millimeter, what you go for it, if there is a margin of error where you're doing a biopsy of two to three millimeters, as you said in your slides, so you are pretty much at the edge whether you'll get it or not.

Yep. You know, when the and is it clinically significant biopsy?

That's the question. It's not just one biopsy.

So the whole area is biopsied and depending upon the size of it, it's a small lesion.

There's a chance in all likelihood they'll get a whole bunch of biopsies in that area.

Because we know that the precision is it's not perfect or might be off a couple of millimeters.

So if you biopsy around the area, you're gonna hit it.

Also, we know that the MR tends to underestimate the true size of the lesion.

So you have that going for you.

Yeah, I mean, if the lesion is well-defined three millimeter lesion, it's certainly a good candidate for biopsy.

But if it comes back negative again, it's catch and release, they go back into the screening pool and we'll if their PSA continues to rise, then we may have another shot at that.

Hesitant Lesions Based on Location

Are there like lesions in the prostate gland that you're still like hesitant to biopsy like certain locations or you're all you know,

Okay, so are there lesions, are there cancer lesions that you see on MR that you're hesitant to biopsy based on location?

Based on location? So are you getting at that hard to reach or near some vital organ?

Is that vital? Okay.

Yeah, it's pretty close to some, it depends on your perspective, but it's usually close to something that at least half the audience considers vital. Yeah.

So in my experience, I have not hesitated a biopsy.

If I see a discrete lesion with targeted biopsies are so precise, I mean, so you go right into it.

We have about a 20% rate of hemorrhage at the time of the biopsy where we can see it on the MRI.

So we biopsying very close to the vessels on the edge.

'cause as you know, a lot of the lesions are peripheral and posterior, but there's no area that you can't biopsy as best I know.

Biopsying Post-Prostatectomy Recurrences

In recurrence cases because UroNav doesn't work. Correct. How do you biopsy them?

Like they did a prostatectomy. Oh, Oh, postoperative cases.

Yeah, so the question is how do you biopsy post prostatectomy cases?

So we've actually gotten into that quite a bit.

And the usually the recurrences are in the perianastomotic region, very close to the urethra.

And frankly, you cannot get good fusion between the ultrasound and the MRI.

So it really is a cognitive biopsy at that point.

That is to say the MR is in the room, the ultrasound is in the room, but there's a lot of estimation about where the lesion is.

Some of the recurrences are off the axis.

So for instance, seminal vesicle or even lymph node not very far into the iliacs, but off to the side.

And those can actually be we've had some luck with doing sort of pick point registration between the ultrasound and the MR.

It the fusions are not excellent, but you can, there's an option to pick specific points that you see on the ultrasound and the MR and use those as reference markers for the fusion.

And we've had some success with that.

But the perianastomotic recurrence is very difficult to do fusion on. In our experience.

We would do those in-bore.

And then sometimes I would say that you can also sometimes do these things under CT guidance if you correlate backwards towards from an MRI to a CT depending on the location.

Yeah, we generally provide the refer with the location and whether or not we think it's amenable to either MR or CT guided biopsy.

And then if it's urologist that wants to try cognitive fusion, he or she might do that.

Otherwise, if again, if it's perianastomotic usually, in-bore targeted biopsy, otherwise CT actually works great.

Dynamic Contrast Scans and Parametric Maps

Okay. Let me ask the unrelated question then.

This has to do with with dynamic contrast hand scans.

So we've in the PI-RADS document we have, it's either positive or negative, and it's based on enhancement, early enhancement, either contemporaneous with surrounding tissues or earlier than surrounding tissues, yet everybody showed parametric maps and I and you know,

and so in the past, our parametric maps, depending upon how you set it up, showed wash in and wash out and we talked about a temporal resolution.

Peter, you were pretty firm about a temporal resolution of five to seven seconds.

I think in the document we have 10 seconds.

I heard somebody else say 15 seconds for temporal resolution, but other people say, well, gee, if you're not using washout, why not?

What's the rush? You know, couldn't you just, do you do you really need to scan for four or five minutes?

Why not just scan for get the scans every 20 seconds for three minutes and do you really need a map for that when in fact you can just toggle between the images and look at them and you know, without getting that, the colors are really nice, we like colors, they make it look really fancy, but are we using those parametric maps anymore?

Do we really need them?

Thanks Jeff for that question.

Yeah, so the goal of PI-RADS I think was to make something standards that were available to everybody regardless of whether they had not insist that they needed to buy specific software to do to do this.

And I think that's a reasonable approach.

Certainly the software is helpful.

I mean, it automatically displays very colorful images that you can point to and say rather than display the data as a movie, you can show it as a single image.

But does it really add information over the raw images?

I don't think there's any evidence to say that that's definitively true.

Now the your other question is really important.

There's a couple questions embedded in there.

One is if you're not gonna do this pharmacokinetic analysis, why do you need to go on for five minutes?

And I agree completely with you.

If you're not gonna do that, then you're really only talking about a minute or so of monitoring things.

I will still maintain though that a good temporal resolution below 10 seconds is important because otherwise it's very it can be difficult to detect early enhancement compared to the rest of the gland.

The rest of the gland's starting to catch up by 15 seconds.

And so you the clarity with which you can pick up focal enhancement starts to decrease.

Whereas with faster resolution, you can see that difference easier.

Most modern machines can easily handle that temporal resolution.

There's just I mean, we have a standard machine, it's not turbocharged and it can do it.

So I think that's a reasonable approach in this.

But I agree with you that you can probably shave a few minutes off the total scan by just truncating the five minute thing.

Anybody else wanna comment on that?

Or has anybody done that?

Because I tell you, we we just stopped scanning out to five minutes and we just scanned for like a I don't know, it's like three minutes or something now.

Probably doesn't save a lot of time, but it's less data to look at.

Actually, that's a great point. 'cause I used to use parametric maps all the time and I've stopped using them.

So something I should consider as well, but I haven't,

We still do the longer scan and I mean, I think there's an educational value we're in teaching hospitals, so certainly for the residents and trainees to understand what contrast enhancement is all about because as you know, we all come, some of us are older than others, but the old days of just, is it enhancing or is it not?

I mean, clearly we've come a long way since then, so I still like to look at them.

I personally, if I'm reading the case with myself, I don't use the PK maps at all.

But we still process the data and it's useful occasionally, but, and we should shorten our scans.

I agree with you. We're probably gonna do that very soon.

So I've got a bevy of physicists that need data for their grant proposals.

Yeah, that's the other part.

I also get a lot of outside reviews.

A lot of people live in Southern California and send their patients to us to re-review their MRs and I have no idea what sort of protocol they're using.

So I use simple subtraction maps and I look for the early enhancement and it works about as well as anything else.

So could you just do 90 seconds?

Probably, could you do a temporal resolution of 30 seconds?

Probably not because of what Pete was saying, that you you wanna be able to catch that time point where there's early enhancement and you need a temporal resolution of 15 seconds or better.

And I would advocate for 10 or five and just go down on your spatial resolution.

Again, this is a functional, not an anatomic evaluation, so you don't need high spatial resolution.

And by going down on your spatial resolution, you bump up your SNR, so you get a little gain on that too.

Closing

Okay. If there's no other questions, I think we've come to the end of the line here.