PET/MR Molecular Imaging of Cancer
October 16, 2024Yale Cancer Center Grand Rounds | September 17, 2024
Presented by: Georges El Fakhri, PhD, DABR
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- 12218
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- 00:00My name is Pam Coons.
- 00:02I'm one of the GI
- 00:02medical oncologists. It's my pleasure
- 00:05to introduce doctor George El
- 00:07Fakhry,
- 00:08for today's,
- 00:10YCC Grand Rounds speaker.
- 00:12He is the I'm gonna
- 00:13do a brief introduction. I
- 00:14promised him I wouldn't. He
- 00:15has so many publications and
- 00:17awards, but I won't read
- 00:17all of them. So doctor
- 00:19Elfackery is the Elizabeth Mears
- 00:21and House
- 00:22Jamieson professor of radiology and
- 00:25biomedical engineering and of biomedical
- 00:27informatics and data science at
- 00:28Yale School of Medicine. He
- 00:30has been here almost exactly
- 00:32one year. Last year, October
- 00:33first was his anniversary.
- 00:35He also serves as a
- 00:36vice chair for scientific research
- 00:38in radiology and the director
- 00:39of the Yale Pet Center.
- 00:42He has a PhD in
- 00:43medical physics,
- 00:44an MS in biomedical engineering
- 00:46from the Paris Sud University,
- 00:48and an MS in electrical
- 00:50and com computer engineering
- 00:52from the University of Texas
- 00:54at Austin and a master's
- 00:55of engineering from a close
- 00:57central in France, and I
- 00:59probably mispronounced that. But he
- 01:01is internationally recognized,
- 01:03in quantitative
- 01:05molecular imaging for in vivo
- 01:06assessment,
- 01:08of pathophysiology
- 01:09in brain, cardiac, and oncologic
- 01:11disease.
- 01:12His current areas of research
- 01:14include high resolution PET MR
- 01:16imaging in a range of
- 01:17diseases,
- 01:19including neurodegenerative
- 01:20disease, traumatic brain injury, cardiac
- 01:22disease, and oncology. Cology. It's
- 01:24really
- 01:26personally, really a pleasure to
- 01:27partner with him as we
- 01:27think about pet imaging and
- 01:27oncology, my area of expertise
- 01:29in neuroendocrine
- 01:30tumors and as we think
- 01:31about really bringing some of
- 01:32his expertise,
- 01:33to clinic. So,
- 01:38thank you so much for
- 01:39joining us today.
- 01:42Thank you very much, Pam,
- 01:43for the kind introduction.
- 01:45I I was reminded it's
- 01:46almost a year I've been
- 01:48using nine months as an
- 01:49excuse that I'm not
- 01:51ready yet, but I guess
- 01:52that's run out now.
- 01:54So it's a pleasure to
- 01:55be here and to share
- 01:56with you,
- 01:57some of what PET NMR
- 01:59can do for you.
- 02:01Part of my job coming
- 02:02in here was to, go
- 02:03below the neck because the
- 02:05Pet Center is world renowned
- 02:07in neuroscience. And,
- 02:09we hope that,
- 02:12I'll give you a taste
- 02:12of what you can be
- 02:14doing with Pet, and with
- 02:15MR,
- 02:18in a center near near
- 02:19you. So I'd like to
- 02:21acknowledge,
- 02:23our funding that comes mostly
- 02:24from the NIH. And I
- 02:25would like to give a
- 02:26shout out to,
- 02:28not only the PET center
- 02:29that you see in this
- 02:30slide, but also the, the
- 02:32imaging group, at Yale. That
- 02:34was from Friday,
- 02:36where we had our first
- 02:38mini retreat. And, they're a
- 02:40pet center. There's an MR
- 02:42center. There's an image processing
- 02:43group over two hundred faculty
- 02:44and postdocs,
- 02:46that do anything that has
- 02:47to do with PET, MR,
- 02:48or optical in all parts
- 02:49of the brain.
- 02:51If you are interested in
- 02:52any of the imaging,
- 02:54all what I'll be showing
- 02:54today is available today at
- 02:56ATL.
- 02:58Some of it may be
- 02:59about to start, because nine,
- 03:01I just keep saying nine,
- 03:02eleven month is a short
- 03:04time. But, from for the
- 03:05most part, it's, all available
- 03:07now, as a revenue neutral
- 03:10core. So,
- 03:11please give me a a
- 03:12line if you're interested in
- 03:14any of this.
- 03:15This is the core I'm
- 03:16referring to, so
- 03:17we do everything from mice
- 03:19to men,
- 03:20including,
- 03:22some animals you may not
- 03:23recognize.
- 03:25Many, many of you are
- 03:26users of the core. I'm
- 03:27not gonna go through all
- 03:28the animals, but there's a
- 03:29woodchuck there and a rabbit.
- 03:32The,
- 03:33some of you are, actually
- 03:34users of the core.
- 03:38There,
- 03:39you are in many, many
- 03:40departments, and we do everything
- 03:42from cell culture to phase
- 03:44one in the core.
- 03:46So I'd like to start
- 03:47with a quick slide about,
- 03:50maybe that's one of the
- 03:51very few about modalities,
- 03:53talking about PET NMR.
- 03:56To highlight that
- 03:57these two modalities are quite
- 03:59symbiotic in that
- 04:01PET is a very high
- 04:02sensitivity modality where we image
- 04:04picomolar concentrations. You'll hear me
- 04:05often during the talk today
- 04:07talk about,
- 04:09you know, measurements that are,
- 04:11at the cellular level.
- 04:13Something we cannot do with
- 04:14MR.
- 04:15We are nowhere near the
- 04:17picomolar or the nanomolar really,
- 04:20in MR.
- 04:21But in PET, we have
- 04:22a very poor resolution and
- 04:24everything is relative. I hope
- 04:25by the end of the
- 04:26talk, I would convince you
- 04:27that's not anymore the case
- 04:29because you'll see images with
- 04:30a one millimeter resolution in
- 04:32PET.
- 04:33But for all intents and
- 04:34purposes, our scanners today are
- 04:36in the four, five millimeter
- 04:37resolution whereas in MR,
- 04:39our resolution is exquisite.
- 04:42We can form many, many
- 04:44images in a very short
- 04:45time without any ionization.
- 04:47Quantitation is quantity is challenging
- 04:49in MR and that's what
- 04:50we do on a daily
- 04:51basis in PET. So you
- 04:53can see that the strength
- 04:54of PET and MR are
- 04:55really the weaknesses of the
- 04:57other modality. And what I'm
- 04:58gonna try to show you
- 04:59today is putting those together,
- 05:00there are a lot of
- 05:01things we can do in
- 05:02cancer
- 05:04that
- 05:05get us to the heart
- 05:06of many diseases.
- 05:07I tried to I will
- 05:09try to show this by
- 05:10body part
- 05:12in the spirit of a
- 05:13grand rounds. But you'll see
- 05:14that a lot of those,
- 05:15there's symbiosis between the two.
- 05:18Our efforts, are part of
- 05:20actually a center of excellence
- 05:22that is one of, twenty
- 05:23in the country. This is
- 05:24the one in Panama. It's
- 05:25the only one in Panama,
- 05:28in the nation. And there's
- 05:29several pieces we are
- 05:32supposed to be doing in
- 05:33this center. One of them
- 05:34is developing new targets, and
- 05:36I'll show you some of
- 05:37the radiochemistry for some of
- 05:38these targets,
- 05:39the ones that are in
- 05:40cancer.
- 05:42But they're also a whole
- 05:43component in terms of,
- 05:45image analysis and processing and
- 05:47in terms of dissemination.
- 05:49And I mentioned this because
- 05:51it is part of our
- 05:52job to,
- 05:54disseminate our work to as
- 05:56many users who are interested
- 05:57as possible,
- 05:58provided their NIH users per
- 06:00NIH rules. But, actually, we
- 06:02often break that rule and
- 06:03we work with everyone. So
- 06:04if you are interested in
- 06:05any of this, please do
- 06:07let me know and we
- 06:07can, discuss afterwards.
- 06:11So I thought I would
- 06:11start in the head because,
- 06:12well, it's,
- 06:14the highest up. And, as
- 06:15I mentioned, we do a
- 06:16lot of work's being done
- 06:17in the brain.
- 06:19And I would like to,
- 06:20I don't know if we're
- 06:21supposed to be monitoring the
- 06:22chat. Oh, this is for
- 06:24you guys. If you wanna
- 06:25have CME attendance, please text
- 06:26four six seven nine three.
- 06:29I think from here on
- 06:30out, we won't look at
- 06:30the chat until the end.
- 06:32So,
- 06:34I'd like to start with
- 06:35some work in MR spectroscopy
- 06:37actually.
- 06:38And this is a nice
- 06:39success story because there's been
- 06:40a lot of work going
- 06:41in my lab in this
- 06:42area led by Chang Ma.
- 06:44And there's a lot of
- 06:44work happening here at Yale
- 06:46in spectroscopy that I will
- 06:48feature some of, and you'll
- 06:49see how the two come
- 06:50together in terms of imaging.
- 06:52The basic idea is that
- 06:55for a long time, what
- 06:56we have done in spectroscopy
- 06:57is looking at a voxel.
- 06:58So if you if you
- 06:59knew where to look, you'll
- 07:01get a good answer. And
- 07:02what you'd hear often is
- 07:03spectroscopy has good potential, but
- 07:05it was never something that
- 07:06is done
- 07:08routinely in the clinic.
- 07:09I hope today I'll I'll
- 07:10convince you that now there's
- 07:11quite a bit that you
- 07:12can do in the clinic
- 07:13without a major burden for
- 07:15your,
- 07:16for your workflow.
- 07:19This is just to show
- 07:20you that the trick and
- 07:21what I'll be showing you
- 07:22in terms of imaging
- 07:23is not to image the
- 07:25whole space,
- 07:26but to only image what
- 07:28we're interested in in terms
- 07:29of metabolites,
- 07:31because that allows us then
- 07:33in our reconstruction of the
- 07:34image to go much faster.
- 07:36And instead of, having, you
- 07:38know, a one scan or
- 07:39one voxel,
- 07:40to have a quantitative t
- 07:42one, t two, and, myelin
- 07:44water fraction and everything else
- 07:45you're interested in,
- 07:47in a time that is
- 07:48very reasonable,
- 07:50for MR, about eight minutes,
- 07:51but with a resolution that
- 07:53is very good. We're talking
- 07:54about, you know, one by
- 07:55one by two millimeters
- 07:57or two by two by
- 07:58three millimeters.
- 07:59And from that, we can
- 08:00estimate then the,
- 08:02all of the,
- 08:03different metabolites we can add.
- 08:05We're showing you here choline,
- 08:07creatidine,
- 08:08CAI, glutamate,
- 08:09glutamine.
- 08:12I will have very few
- 08:13images in normal subjects only
- 08:15just to make a case.
- 08:16I know this is a
- 08:16cancer round, but this is
- 08:17one of them.
- 08:19And now we look at
- 08:20a brain tumor, and you
- 08:21can see that,
- 08:23now the value of having
- 08:24a whole image of spectroscopy
- 08:26as opposed to a whole,
- 08:28voxel spectroscopy,
- 08:30is that now we can
- 08:31assess in the entire brain,
- 08:33the different signatures of the
- 08:35tumor, the tumor rim, the
- 08:37necrosis necrotic component, and the
- 08:39edema, which have different signatures.
- 08:42We can push this, further
- 08:45and look
- 08:46at,
- 08:47actually, this is a little
- 08:48longer now. It's, it's twelve
- 08:50minutes, but, you can see
- 08:52here that,
- 08:54the signature on the different,
- 08:56metabolic components,
- 08:57for example, the lactate and
- 08:59the choline are very different
- 09:00for the same tumor.
- 09:02And that allows you to
- 09:03start having some insight into,
- 09:06you know, what is the
- 09:07hypoxic component, what is the
- 09:08two HD or the IDH
- 09:10mutation,
- 09:11for that
- 09:12for that glioma in this
- 09:13case.
- 09:15And then this is in
- 09:16the Maersh spectroscopy side.
- 09:18We can also add the
- 09:19PET. Just one more slide
- 09:21to show you that this
- 09:22is not just a pretty
- 09:24image.
- 09:24What I'm showing you here
- 09:26is the,
- 09:27on top is the the
- 09:28clinical t one weighted and
- 09:30FLAIR t two.
- 09:31And in the middle row
- 09:32is the quantitative t one
- 09:34t two maps.
- 09:36And,
- 09:37in the bottom are the,
- 09:39NAA choline lactate.
- 09:41It's not just a pretty
- 09:42image. You can see that
- 09:44the discrimination we have and
- 09:46this is the manual annotation
- 09:48by the,
- 09:49neuroradiologist.
- 09:50You see the discrimination between
- 09:52the,
- 09:53edema and the tumor
- 09:55is done much better
- 09:56when you have access,
- 09:59to your, metabolic images from
- 10:01MRSI
- 10:02than it is when you
- 10:03have access only to your
- 10:05clinical MR. It is not
- 10:07as different when you're looking
- 10:08at the lesion versus normal.
- 10:10There, it's pretty clear.
- 10:12I want you to look
- 10:12at the green
- 10:14curve and the blue curve.
- 10:15These are the receiving operating
- 10:17characteristics. So the ROC curves
- 10:19for,
- 10:20what is true.
- 10:21And you can see that
- 10:22we do a lot better
- 10:23when we have
- 10:25the MR,
- 10:26s information compared to when
- 10:28we have only the MR
- 10:29information.
- 10:31And next, we're gonna look
- 10:32also at, we can add
- 10:34the PET.
- 10:36And we can see that
- 10:37in this case,
- 10:38we're looking at an amino
- 10:40acid, the, fluoroethyl,
- 10:41tyrosine
- 10:42in addition to tyrosine in
- 10:44addition to the MRSI.
- 10:46And and I hope you
- 10:47can see where I'm going
- 10:48with this. The idea is
- 10:49that now
- 10:51we can see on the
- 10:52t two flare, well, the
- 10:53entire tumor plus edema.
- 10:55You can see on spectroscopy
- 10:56the areas that are, this
- 10:58is a low grade glioma.
- 10:59You can see the areas
- 11:00that are, there are more
- 11:02involved in terms of
- 11:04metabolism.
- 11:06And then you can see
- 11:07from,
- 11:07the FET, the subset of
- 11:10that tumor,
- 11:11there is the more aggressive
- 11:12component.
- 11:14And that, you know, can
- 11:15be one way to look
- 11:16at image guided
- 11:18radiotherapy
- 11:19based on the biology as
- 11:20opposed to, a hunch.
- 11:23And you can see on
- 11:24the on the right side
- 11:25the the signature of these,
- 11:26which are, on the MRSI,
- 11:28which are different.
- 11:29This is all done with,
- 11:31this is work done by
- 11:32Chao Mang, and a grant
- 11:33he just started, with, Proton.
- 11:37And now we can do
- 11:38also,
- 11:39deuteron. This is the work
- 11:40of, Hank Fader and, Robin
- 11:42de Graaf here at Yale.
- 11:43We're, now we're looking at
- 11:45the deuterium metabolic imaging. So
- 11:47we're not looking at the
- 11:48h one now. We're looking
- 11:49at the h two here.
- 11:51Just that number changes, but
- 11:52a lot of things go
- 11:53with that. And we can
- 11:54look now at a three
- 11:55d map of the glucose
- 11:57deuterium metabolic imaging, the glutamate,
- 11:59glutamine,
- 12:01all of those in
- 12:03in a human four t
- 12:04scanner.
- 12:05This is again,
- 12:07a this is now a
- 12:08little larger
- 12:09voxel. Now we're talking about
- 12:11a two centimeter isotropic,
- 12:13in a thirty minute. But
- 12:14remember, this is now
- 12:16a deuterium that we're imaging,
- 12:17not pro, proton
- 12:21water.
- 12:22So signal is definitely less.
- 12:24The the way we do
- 12:25this is no different than
- 12:26what you're used to with,
- 12:27glucose,
- 12:28FPG. You would,
- 12:30you know, instead of having
- 12:31an IV injection, you would
- 12:32drink some,
- 12:34drink some glucose,
- 12:35wait for seventy five minutes,
- 12:37and then, your image for
- 12:38forty five minutes.
- 12:40Here's some of the typical
- 12:41image you'd see. You would
- 12:42see this is one of
- 12:43series of twenty three patients
- 12:45with brain tumors that have
- 12:46been,
- 12:47imaged now by,
- 12:49by Hank,
- 12:51where, you could interleave your
- 12:53MR with your, deuterium metabolic
- 12:56imaging. So you'd have both
- 12:57about the same time.
- 12:59It's a forty five minute
- 13:00protocol. So it's still a
- 13:02little long, but it's not,
- 13:04you know, impossible to do.
- 13:06And I'd like to draw
- 13:06your attention to the to
- 13:08the bottom where not only
- 13:09you can see the glutamine,
- 13:10glutamine, lactate, but the ratio
- 13:11of lactate to glutamine is
- 13:13actually an indicator of the
- 13:14Warburg effect,
- 13:16and that is indicative of
- 13:17the aggressiveness of the primary
- 13:19tumor. So we are getting
- 13:21now more of a window
- 13:22into the functionality of that
- 13:24tumor as opposed to only
- 13:25the appearance that we have
- 13:26from the t two.
- 13:28Last slide on MRSI is
- 13:30to show you that we
- 13:31can also look at the,
- 13:32choline metabolism in these brain
- 13:34tumors.
- 13:35As you know, choline is
- 13:37a precursor to acetylcholine
- 13:38neurotransmitter in the brain, but
- 13:40it's also a key component
- 13:41of the bio membrane.
- 13:43And, the choline transport is
- 13:46and the metabolism is regulated.
- 13:48It's upregulated in many cancers,
- 13:49so,
- 13:50especially brain tumors.
- 13:52So the idea here is,
- 13:54that by, you know, you
- 13:56can have it,
- 13:58either IV or, you can
- 13:59drink it. And in both
- 14:01cases,
- 14:02you can see that,
- 14:05seventy five minutes later, you
- 14:06you have a signal
- 14:08that is now,
- 14:10the area of,
- 14:11choline metabolism in in the
- 14:13brain. So, and this is
- 14:15now without an amino acid
- 14:17PET injection. So you see
- 14:18that there's there's a lot
- 14:19of, duality here in what
- 14:21we're doing, and doing one
- 14:22or the other allows you
- 14:23to see more.
- 14:25Now I hope you've noticed
- 14:26that the images I've shown
- 14:27you of the brain were
- 14:28very poor quality. If you
- 14:30didn't, you're very polite. But
- 14:32but these are the kind
- 14:33of images that we're all
- 14:35used to seeing in PET.
- 14:37Those are images at a
- 14:38resolution of about, four millimeters,
- 14:40five millimeters. So for a
- 14:42volume, that would be a
- 14:43hundred and twenty five millimeter
- 14:45cubed.
- 14:46What I'm gonna show you
- 14:47next are images now at
- 14:49two millimeters or one point
- 14:50five millimeters. So,
- 14:52you know, something around six
- 14:54millimeter cubed. So about
- 14:56twenty five times a better
- 14:57spatial resolution.
- 14:58This is,
- 15:00a new brain system, a
- 15:01neuro explorer that has just
- 15:02been installed at Yale,
- 15:04funded by a u o
- 15:05one led by Rich Carson
- 15:07at Yale and United Imaging,
- 15:10health in Houston.
- 15:12And the idea here is
- 15:13to go with a very
- 15:14small crystal
- 15:16with a very large,
- 15:18coverage of the brain,
- 15:20very unusual to what we
- 15:21do today. This is about
- 15:22fifty centimeters of axial coverage.
- 15:25And the reason is
- 15:27we would like to get
- 15:28the highest sensitivity possible,
- 15:30and I'll show you some
- 15:31clinical implications or benefits of
- 15:33that.
- 15:35You can think of that
- 15:36both in terms of, well,
- 15:36you could inject a lot
- 15:38less,
- 15:38but also in terms of
- 15:40you can see signal in
- 15:41the marginal lesion detectability, what
- 15:43we call marginal lesion detectability.
- 15:45Those tumors, they are the
- 15:46the hardest to see because
- 15:47the contrast to background is
- 15:48the the lowest.
- 15:50And now you can start
- 15:51seeing things we're we're not
- 15:52used to seeing. And I'll
- 15:53show you some examples of
- 15:54both.
- 15:54So I'm gonna start with,
- 15:56like, maybe the second slide
- 15:57of a normal,
- 15:59no cancer,
- 16:00but to drive the message
- 16:02of what high resolution and
- 16:04sensitivity buys you.
- 16:06So for those who are,
- 16:07fans of astronomy, think of
- 16:09the HRT, which has been
- 16:10the best system we've had
- 16:12as the Hubble Telescope.
- 16:13And that is still much
- 16:14better than a regular, brain
- 16:16scanner. Those images actually are
- 16:17better than the ones you
- 16:18see in the clinic.
- 16:19And this is the neuro
- 16:20explorer, which think of it
- 16:21as maybe the Webb telescope.
- 16:23And, here you have a
- 16:24twenty five
- 16:26fold better image resolution and,
- 16:29twenty fold,
- 16:30sensitivity.
- 16:31So now we're starting to
- 16:32see cortical ribbon. We're starting
- 16:33to see central,
- 16:35brain structures. We're seeing the
- 16:36horn of the chordate nucleus,
- 16:37the basal ganglia, things that
- 16:39until now we we know
- 16:40about in neuroanatomy, but in
- 16:41PET, we don't usually see.
- 16:43So what does that do
- 16:44to us in oncology? So
- 16:46here's an example of,
- 16:49another brain tumor that,
- 16:51is again
- 16:53well well characterized on FLAIR.
- 16:55But what I would like
- 16:56to show you is the
- 16:57FDG scan of that patient,
- 16:59both on a clinical
- 17:01scanner
- 17:02and on the neuro explorer.
- 17:03And I do hope
- 17:05yes. I can see it.
- 17:06I hope you see it
- 17:07over there. Can you see
- 17:09my cursor when I'm moving
- 17:10over there? You can. Oh,
- 17:11good. Because usually by the
- 17:13end of the talk is
- 17:13when the speaker asks, can
- 17:14you see my cursor? So
- 17:16at least at least I
- 17:17asked only twenty one slides
- 17:19into my seven hundred slides.
- 17:21So I hope you can
- 17:22see the lesion here.
- 17:24And unless you're,
- 17:27really really good, I don't
- 17:28think you can see it
- 17:28here.
- 17:30That's a good example of
- 17:31what a gain in sensitivity
- 17:33buys you,
- 17:34when, imaging with PET.
- 17:38Alright.
- 17:39So we're gonna move to
- 17:40sarcomas.
- 17:41And,
- 17:42here I'm gonna try to
- 17:44show you some examples,
- 17:46of what PET and a
- 17:47Marsh Petrosky can do together.
- 17:49You Starting to see a
- 17:50theme. This started with, a
- 17:52grant we were in our
- 17:53own, we're working on where,
- 17:55basically, we had asked a
- 17:56question for many of the
- 17:57sarcomas,
- 17:59who,
- 17:59for many of the patients
- 18:00who refuse to have surgery.
- 18:02We we do have about
- 18:04thirty percent of patients who
- 18:05say, no. I wanna forego
- 18:06surgery because I wanna go
- 18:07back to work,
- 18:08less than a year later.
- 18:10There is a risk of
- 18:11recurrence. And so there are
- 18:12two questions. The first one,
- 18:14well,
- 18:15can we tell if we've
- 18:16treated everything or not? And
- 18:17two, if there is recurrence,
- 18:19are you able to tell,
- 18:21early enough?
- 18:22And the answer to two
- 18:23of the those two is
- 18:25yes. I hope to I
- 18:26hope I'll be able to
- 18:26convince you of that.
- 18:28Just know that from the
- 18:29radiation oncology side, and there's
- 18:31no critique by no
- 18:33mean, the current consensus is
- 18:35quite crude. Basically, it's, you
- 18:36know, you take a three
- 18:37and a half centimeter
- 18:38longitudinal, one and a half
- 18:39centimeter radial, blast that, and
- 18:41you're good.
- 18:43And the question is, well,
- 18:44is that really necessary?
- 18:46And again, this is not
- 18:47at all we we work
- 18:48very, very closely with many
- 18:50of our radiation oncologists. This
- 18:51is not at all by
- 18:51any mean, a criticism, but
- 18:53these are, what we call
- 18:55gross target volume. So that's
- 18:56what we've decided is the
- 18:58tumor,
- 18:59that was delineated by multiple,
- 19:01radiation oncologists and okay. And
- 19:03maybe a couple of residents.
- 19:04And the message we're trying
- 19:06to convey here is that,
- 19:09depending on who's doing
- 19:12what at what time of
- 19:12the day, your contour will
- 19:14vary.
- 19:16So don't hope for a
- 19:17very reproducible
- 19:19treatment that you'd have the
- 19:20same way if two physicians
- 19:22did the same.
- 19:23And the message from that
- 19:24is not, oh, you shouldn't
- 19:25do it. The message of
- 19:26that is, is there a
- 19:27way we could reduce that
- 19:28variability? And I'll show you,
- 19:30that yes. We can. Alright.
- 19:31So let's start with the
- 19:32first question. So here's one
- 19:33example.
- 19:34This is a six year
- 19:35old female with a soft
- 19:37tissue circum of the right
- 19:38leg.
- 19:40This is your t two,
- 19:42enhanced MR. So based on
- 19:43that, all of this would
- 19:44be treated because some of
- 19:45it is tumor, some of
- 19:46it is edema. We don't
- 19:47know what is what.
- 19:48This is your pet signature.
- 19:50We see that it's mainly
- 19:51this area that is actually,
- 19:53active and the rest is
- 19:54not.
- 19:57Oh, somebody's trying to do
- 19:58something else while listening.
- 20:01And,
- 20:02of course, on pathology that
- 20:04is confirmed, this is the
- 20:05area that is, the the
- 20:06tumor and on, on a
- 20:08pathology, it's, that's confirmed. Now
- 20:10don't take my word for
- 20:11it. If this was my
- 20:12my grandmother, I would say
- 20:13no treat the whole thing.
- 20:15But,
- 20:16but doing this enough times,
- 20:18now we've seen that, you
- 20:19know, every time every time
- 20:21what you see on FDG
- 20:22is what you see on
- 20:22pathology.
- 20:23So, yes, you could, you
- 20:25know, use PET to guide
- 20:26your treatment.
- 20:27And the second question was,
- 20:28well, after treatment now, can
- 20:30can pet help me with
- 20:31determining if determining if there
- 20:33is any remaining? And the
- 20:34answer is no.
- 20:35Because, yes, in this case,
- 20:37for example, you see there
- 20:38is signal here,
- 20:40but we don't know if
- 20:41this is tumor or if
- 20:43this is simply
- 20:45inflammation post treatment.
- 20:47MR spectroscopy, on the other
- 20:48hand, can help you. So
- 20:50here's, an example, that that
- 20:52same example where
- 20:54this is the healthy contralateral
- 20:56leg where you see the
- 20:57choline protein ratio is normal.
- 21:00This is the,
- 21:01tumor where you see that
- 21:02the choline protein ratio is
- 21:04overtly abnormal.
- 21:05And in that area, you
- 21:06didn't know what to do
- 21:07with PET. Well, the ratio
- 21:09is normal and sure enough,
- 21:10a month later that has
- 21:11resolved.
- 21:12So you see that using
- 21:14both, has a value because,
- 21:17the pet can guide you,
- 21:18but I can't tell you
- 21:19in this case whether it's
- 21:20a remaining tumor,
- 21:21or not, and, a Mars
- 21:23spectroscopy can.
- 21:24Now this was,
- 21:26easier said than done. What
- 21:27we actually did, this is
- 21:29the ugly part of it,
- 21:30is in order to map
- 21:32absolutely
- 21:33and be absolutely sure what
- 21:34is where,
- 21:35I showed you all look
- 21:36this the path and pathology
- 21:38agrees. What we did really
- 21:40was,
- 21:41we did an MR. We
- 21:42did a three d printing
- 21:43of the tumor
- 21:44and of its surrounding.
- 21:45When the tumor was excised,
- 21:48it was taken in
- 21:50and frozen in this mold,
- 21:52then it was sliced.
- 21:54We had to pay a
- 21:55lot of chocolate and champagne
- 21:57and drinks for the pathologist
- 21:59who agreed to do not
- 22:00two slides, but forty slides
- 22:02out of one slice.
- 22:04And now you have your
- 22:07pathology and your pet absolutely
- 22:09in the same reference.
- 22:11And and now you have
- 22:12a validation slide by slide.
- 22:14This is very important because
- 22:15if we're gonna do any
- 22:16deep learning, we need that.
- 22:18And I'll show you some
- 22:19of what we've done with
- 22:20this. It is very hard,
- 22:22very lengthy, but there is
- 22:23no shortcuts if you really
- 22:25wanna do this, the right
- 22:26way.
- 22:28Remember I showed you a
- 22:29slide of big variability in
- 22:30the GTV.
- 22:32We have been working on
- 22:33this
- 22:34not to replace the radiation
- 22:36oncologist,
- 22:37but to provide the radiation
- 22:38oncologist with a starting point
- 22:40so they save time.
- 22:41In the US, you know,
- 22:42we have radiation oncologist who
- 22:44are specialized in head and
- 22:45neck, in sarcomas, in
- 22:47CNS.
- 22:48In many parts of the
- 22:49world and,
- 22:50including Germany, France, China, many
- 22:52other countries,
- 22:53they do all parts, all
- 22:55body parts.
- 22:56So when you're starting, it's
- 22:57really nice to have something
- 22:58that can be a a
- 22:59place you can start from
- 23:00and adjust. It saves you
- 23:02time. It increases your
- 23:04productivity,
- 23:05and it's a good,
- 23:07training tool. So the idea
- 23:08here was,
- 23:10not to learn from what
- 23:11one radiation oncologist can draw
- 23:13in terms of gross target
- 23:14volume or clinical target volume,
- 23:16but to have many of
- 23:17them do the same thing
- 23:19and have the neural network
- 23:21learn from all of those
- 23:23as opposed to learning from
- 23:25one contour.
- 23:26This is a lot harder
- 23:27because now you don't have
- 23:28a truth. You have more
- 23:30of a level of confidence
- 23:31based on where they agree.
- 23:33It takes a lot longer
- 23:34to learn. You need more
- 23:35data. And you're not gonna
- 23:37be as accurate
- 23:38as if you had one
- 23:40traditional colleges because what you're
- 23:41learning is the variability.
- 23:44However,
- 23:45that will allow you to
- 23:45be a lot more robust.
- 23:47Meaning,
- 23:48if you go to a
- 23:49different hospital,
- 23:50if you go to a
- 23:51different setting, you'll still be
- 23:52fine because what you've learned
- 23:54is a confidence level as
- 23:55opposed to a black and
- 23:56white. So instead of having
- 23:57one contour, what you will
- 23:58have at the end, what
- 23:59I'm showing you here is
- 24:00a confidence level. So let
- 24:02me show you some results
- 24:03of how well we do
- 24:04with this.
- 24:05These are
- 24:07patients that were never presented
- 24:08to the network until validation
- 24:10where you can see,
- 24:11that there's a very good
- 24:13agreement between what the consensus
- 24:16between,
- 24:16the radiation oncologist is, or
- 24:19I should say therapeutic radiologist,
- 24:21at Yale. And, what the
- 24:23level of confidence you have
- 24:25from the network. The hotter
- 24:26the yellower, the hotter. And,
- 24:29and the orangier,
- 24:30the less. I should have
- 24:31picked different colors, I guess.
- 24:33And you see that the,
- 24:34accuracy is not, you know,
- 24:35very good. It's in the
- 24:36eighty six percent, which is
- 24:37where we expected. It's not
- 24:39ninety nine percent. And, frankly,
- 24:40I don't believe in network
- 24:41that does ninety nine percent
- 24:42because you take it to
- 24:43a different location, it won't
- 24:45do as well. However,
- 24:47we are capturing very well
- 24:48the inter observer variability
- 24:50and, from the CT, the
- 24:51clinical target volume, we're doing
- 24:53also very well,
- 24:54with the compared to what
- 24:55was predicted.
- 24:57This is an example showing
- 24:58you now that if you
- 24:59did that instead of doing
- 25:00it only on CT, if
- 25:01you did with PET,
- 25:02you reduce your variability, you
- 25:04increase your reproducibility, which is
- 25:06what you would expect.
- 25:07And this is showing you
- 25:09that,
- 25:09you know, we can do
- 25:10this now in a more
- 25:12sophisticated way with diffusion networks,
- 25:15but the resolution,
- 25:16is about the same. We're
- 25:17still in the eighty eight
- 25:18percent. It's just that we're
- 25:19now more resilient to, to
- 25:21noise.
- 25:23Alright. This has shown you
- 25:24that we can do this
- 25:25also for the clinical target
- 25:26volume, not just for the
- 25:27gross target volume.
- 25:29I'd like to move now
- 25:30to head and neck. We're
- 25:31excited that we're starting a
- 25:33new, project now looking at
- 25:35this in head and neck
- 25:36as opposed to sarcomas,
- 25:38where we're looking again, how
- 25:39is the contribution from PETCT
- 25:41or taken together, and how
- 25:43well can we do?
- 25:45I hope you can see
- 25:46here that we can delineate
- 25:47very accurately the, the tumor.
- 25:50And, more importantly, I wanna
- 25:52show you what you can
- 25:53do now if you have
- 25:55a much better sensitivity with
- 25:56your PET scan, again, compared
- 25:58to what we're used to.
- 26:00So those are the same,
- 26:01Webb Telescope images.
- 26:03Now this is the work
- 26:04of, the creator Inaga in
- 26:06our group who is looking
- 26:07at,
- 26:08head and neck cancer within
- 26:09our explorer. So much higher
- 26:11sensitivity,
- 26:12much higher resolution,
- 26:14same patients scanned on our
- 26:16clinical
- 26:17vision
- 26:18and our,
- 26:20research for now, NeuroExplorer, which
- 26:22is FDA approved by the
- 26:23way. Some of those are
- 26:24very obvious. You see the
- 26:26lesion very well in both.
- 26:27What I would like you
- 26:28to notice is, one, that
- 26:30the lesion delineation is clearer
- 26:33and the contrast is higher.
- 26:34That is not a higher,
- 26:36glycolytic rate of the tumor.
- 26:38It's exactly the same tumor.
- 26:39It's just that we have
- 26:40less partial volume effect. That's
- 26:42all.
- 26:43These are lymph nodes in
- 26:44the left neck where you
- 26:45see,
- 26:46same story.
- 26:48And in the base of
- 26:49the tongue, same story again,
- 26:50where you have a much
- 26:51better deniation of the anatomy
- 26:53and of the tumor.
- 26:56This is a lymph node
- 26:57in the left neck, and
- 26:58I think I have one.
- 26:59Yeah. This one I like.
- 27:00And this is, again,
- 27:02lymph node left neck, but
- 27:04what I draw what I
- 27:04would draw your attention is
- 27:06to this component of the
- 27:07tumor, which is barely visible
- 27:09and clearly visible on,
- 27:12on the nurse core.
- 27:15Okay.
- 27:16I think you've seen enough
- 27:17good pictures. Let's move to
- 27:18the next, some basic science.
- 27:20Now we're gonna move to,
- 27:22more basic science in terms
- 27:24of,
- 27:26a new radio
- 27:27a a new a new
- 27:29target.
- 27:29What we're looking here at
- 27:31is measuring the membrane potential.
- 27:33And you can think of
- 27:34the membrane potential as the
- 27:35battery,
- 27:36of life for the cell
- 27:37because that's the that's what
- 27:38the mitochondria uses,
- 27:41in its role as an
- 27:42energy plant,
- 27:43so as a power plant.
- 27:45So that's what we use
- 27:46to convert our, ADP to
- 27:48ATP,
- 27:49and
- 27:50this is the canary in
- 27:51the mine. It is affected
- 27:53very early on,
- 27:55anytime there is a change
- 27:57in the reactive oxygen species.
- 27:59So you'll see this affected
- 28:01long before
- 28:02other more,
- 28:04anatomical
- 28:05or functional. I'll show you
- 28:06some examples.
- 28:09Parameters we measure usually are
- 28:11are affected.
- 28:12Okay. So
- 28:14let let's, let's dig into
- 28:15this. This has been known
- 28:17for for a long time,
- 28:18as something you can measure
- 28:20with treated compounds
- 28:22in dead in
- 28:24in in cells but in
- 28:24dead people.
- 28:25The idea here was to
- 28:26do this in vivo in
- 28:28living humans. So
- 28:29we labeled,
- 28:31the tryphalan phosphonium with f
- 28:32eighteen, and then,
- 28:34we set out to measure
- 28:36that membrane potential, which would
- 28:37be basically if you had
- 28:38a
- 28:39nano electrode inside the cell
- 28:41and one outside the cell,
- 28:42that would be the voltage
- 28:43difference you would see.
- 28:45That's what we're trying to
- 28:46measure.
- 28:47I'll spare you the kinetic
- 28:49modeling, which is what a
- 28:50lot of us spend our
- 28:51time doing.
- 28:52But I wanna I wanna
- 28:53just point out that what
- 28:54you're measuring here is the,
- 28:57voltage in millivolts,
- 28:59not arbitrary units.
- 29:02That was published in twenty
- 29:03twenty, and here's some of
- 29:04the applications. The one I'll
- 29:05show you obviously is the
- 29:07one that has to do
- 29:07with cancer.
- 29:09So,
- 29:09what we look at is
- 29:11cardiotoxicity,
- 29:12but before we go there,
- 29:13I would like to show
- 29:14you this graph to show
- 29:15you that
- 29:16the membrane potential measurement is
- 29:18incredibly
- 29:19well preserved in humans.
- 29:21And rightfully so because it's,
- 29:23as I told you, the
- 29:23canary in the mind. So
- 29:25this is very valuable because
- 29:26that means that when we're
- 29:27gonna set out to imaging
- 29:29that in patients versus healthy
- 29:31controls,
- 29:32the difference will be due
- 29:33to the disease, not to
- 29:34variability in the patients. Because
- 29:36this is many, many patients
- 29:37that were scanned, and you
- 29:38can see that they're plotted
- 29:39here and they're all about
- 29:41the same.
- 29:43Alright. So cardiotoxicity,
- 29:44why are we doing this?
- 29:46As you know,
- 29:47patients who receive doxorubicin
- 29:49in breast cancer, for example,
- 29:52they,
- 29:52they have serious side effects
- 29:54that not all not always
- 29:56manifest immediately. Sometimes it's
- 30:00months and years later. And
- 30:02these can be very healthy
- 30:03otherwise patients. So there's
- 30:05very little in terms of
- 30:06predictive,
- 30:08prediction of who's gonna
- 30:10go for,
- 30:12cell death and heart failure
- 30:13other doctor Rubinstein versus who's
- 30:14not going to.
- 30:16One of the measurements we
- 30:17do is the left ventricle
- 30:18ejection fraction,
- 30:20but that's a little bit
- 30:22late. By the time you
- 30:24see the ejection fraction changing,
- 30:26a lot of the harm
- 30:27has been done. And I'll
- 30:28show you in the experimental
- 30:29model that
- 30:30that's the case. So the
- 30:32idea here is, is there
- 30:34a way we could predict
- 30:36long before ejection fraction has,
- 30:39started to telling us there's
- 30:40something wrong,
- 30:41that, you know,
- 30:43it's too late?
- 30:44Alright. And that's where
- 30:45we would like to,
- 30:47intervene with,
- 30:49membrane potential PET imaging.
- 30:51Alright.
- 30:53Let's see. First, I'm gonna
- 30:54show you some acute,
- 30:55examples because,
- 30:57in physiology, you always have
- 30:59to show
- 31:00effect in in real time
- 31:01before we go to more,
- 31:03more long term, and I'll
- 31:04then I'll show you the,
- 31:06chronic care model. So in
- 31:07the acute model,
- 31:08these are pigs that are,
- 31:10I'm showing here results in
- 31:11eight pigs. They're you know,
- 31:12we have an intervention. We
- 31:13go into the LAD. We
- 31:14inject,
- 31:16acutely
- 31:17docservicin in the LAD, and
- 31:18we expect to see
- 31:20a drop in the membrane
- 31:21potential transiently
- 31:24in the anterolateral wall, you
- 31:25know, insert in the anterior
- 31:26wall and septal wall, but
- 31:28not in the inferior wall
- 31:29because we didn't inject anything
- 31:31in the right circumflex. So
- 31:32the right circumflex serves as
- 31:34the,
- 31:35control in each in each
- 31:36animal and you should see
- 31:38in this area a drop
- 31:39the membrane potential in millivolts
- 31:41and this area no drop
- 31:42and that's exactly what you
- 31:44see. Alright. That's the chronic
- 31:46model. And when we form
- 31:47the images of these, again,
- 31:49these units here are in
- 31:50millivolts. You see minus one
- 31:51twenty millivolts and in the
- 31:53anterior and septal, there is
- 31:54a drop, but in the
- 31:55inferior wall, there's none.
- 31:57Then we move to the
- 31:58chronic setting. That's the more
- 31:59complicated study. Now we're treating
- 32:01pigs as, patients who have
- 32:03a breast cancer,
- 32:05over, several months.
- 32:07And
- 32:08the figure I would like
- 32:09you to leave, if there's
- 32:10one figure to leave for
- 32:11doc cardiotoxicity with is this.
- 32:13This is the membrane potential
- 32:16of those pigs over time,
- 32:17and you can see that
- 32:18this was before treatment.
- 32:20You see how it drops
- 32:23very quickly?
- 32:24Whereas the left ventricle ejection
- 32:26fraction stays on for a
- 32:27while
- 32:28before it drops.
- 32:30What is interesting is that
- 32:31when we start treatment,
- 32:34you know, the
- 32:36the ventricle ejection fraction drug
- 32:37goes up again very quickly.
- 32:39Whereas with the,
- 32:41sorry, the membrane pressure goes
- 32:43up quickly whereas the ejection
- 32:44fraction doesn't. So this is
- 32:46a canary in the mind
- 32:47that allows you, in this
- 32:49case, after six cycles, to
- 32:50determine where you are in
- 32:51terms of,
- 32:53in terms of,
- 32:55viability of the tissue. And
- 32:57this is a study that
- 32:58we will be starting here
- 32:59at Yale,
- 33:00next month.
- 33:02Alright. Last part of my
- 33:03talk, I would like to
- 33:04cover some of the,
- 33:06again, more exploratory in, imaging
- 33:08immune response with PET. And
- 33:10we're gonna start with Feraheme,
- 33:11which is an MR contrast
- 33:12agent. That's fermoxetil. It's an
- 33:14iron particle that is actually
- 33:15FDA approved for, anemia.
- 33:18Because, over, over time the,
- 33:21the bioavailable iron, the nano
- 33:24particle core dissolves and the
- 33:25bioavailable iron becomes exposed and
- 33:27that's a treatment for anemia
- 33:28that is approved. But it
- 33:29started as an MR contrast,
- 33:31and there have been several
- 33:32clinical trials done in that
- 33:34space because,
- 33:35you know, it it will
- 33:36track lymph nodes and you
- 33:37can see lymph node involvement.
- 33:39The only problem is because
- 33:41it's an MR contrast, you
- 33:42have a few minutes to
- 33:43see it. And after ten,
- 33:44fifteen minutes, the signal is
- 33:45gone. So the idea was,
- 33:46well, if we label this,
- 33:47and in this case, I'll
- 33:48spare you the radiochemistry, but
- 33:49it's basically a chelation where
- 33:51you heat,
- 33:52the core and then, the
- 33:53the zirconium
- 33:55eighty nine goes into the
- 33:56core
- 33:57of the, fermoxetal
- 33:58and stays there forever.
- 34:00If we label that, we
- 34:01could follow then for a
- 34:02long time,
- 34:04that,
- 34:05that, compound as it,
- 34:08distributes in the body.
- 34:10And, this is where we
- 34:11were very very surprised.
- 34:13This is an example in
- 34:14an animal that had,
- 34:16a skin lesion.
- 34:18This is a nonhuman primate
- 34:19where, now you see the
- 34:21time is two hundred hours.
- 34:22We're following for a long
- 34:23time because zirconium eighty nine
- 34:24allows you, to follow the
- 34:26enemy.
- 34:27You can see that the
- 34:28uptake in the ipsilateral lymph
- 34:30nodes was going up over
- 34:31time,
- 34:32but there is no circulating
- 34:34activity anymore. You know, the
- 34:35activity after a few minutes
- 34:37has distributed, and that's it.
- 34:39So this is not circulating
- 34:40activity. This is
- 34:42active trafficking of monocytes.
- 34:45And that was our first,
- 34:46discovery in this, the totally
- 34:48scientifically because we we didn't
- 34:49expect to see that over
- 34:50time.
- 34:52So I'll show you now
- 34:53another example of,
- 34:55what we can do with
- 34:56this.
- 34:57Those of you old enough
- 34:58to know white blood cell
- 34:59imaging, Indian white blood cell,
- 35:01remember how we draw bloods
- 35:02and then he labeled Indian
- 35:03and,
- 35:04well, this is a spin
- 35:05on that. No pun intended.
- 35:07But now we're,
- 35:09we draw the blood and
- 35:10then we isolate by, you
- 35:12know, by facts the t
- 35:13cells and the b cells.
- 35:14And we can isolate the
- 35:16monocytes also,
- 35:17by buffy coat extraction.
- 35:19And then you label those
- 35:21b cells or t cells
- 35:22with the zirconium for a
- 35:23hem, then you reinject them.
- 35:25And now what you see
- 35:26is, this is an EAE
- 35:27model, where we're labeling the
- 35:29b cells. And you can
- 35:30see that,
- 35:31when, you have EAE induction,
- 35:33you do see,
- 35:34uptake in the, area of
- 35:36lesion. Whereas when, you don't
- 35:38have,
- 35:40the EAE model, when you
- 35:42when you have a sham
- 35:43induction without labeling of the
- 35:44b cells, you don't see,
- 35:46uptake in that area. And
- 35:47the same with the immunomodulator
- 35:49with the t cells. You
- 35:50see that, with the immunomodulator,
- 35:52you have a drop when
- 35:54you're doing the t cells.
- 35:55Whereas when you're doing the
- 35:56sham or n p injection,
- 35:58you don't see that drop.
- 35:59So this is to peak
- 36:01your curiosity about what you
- 36:03could do now,
- 36:04imaging t cells and b
- 36:05cells in the body,
- 36:07as opposed to and you
- 36:08can see if they're going
- 36:09to the spleen, well, nothing's
- 36:10happening or they're going to
- 36:11the tumor. Well, that's a
- 36:12real, immune
- 36:15recruitment.
- 36:16This is a compound that
- 36:17we hope to bring to
- 36:18man here at Yale.
- 36:20It is part of,
- 36:21a large study where we've
- 36:23done now the dosimetry. It
- 36:24is, all very promising.
- 36:26Really chemistry,
- 36:28purity is also very good.
- 36:30And we're hoping that, you
- 36:31know, within a year from
- 36:32now, this will be in
- 36:33humans here, with an IND.
- 36:36Alright. I'd like to close.
- 36:37I have still a few
- 36:38minutes. I'd like to close
- 36:39with,
- 36:40the piece de resistance, which
- 36:42is
- 36:43the rhinostics and the role
- 36:44of pet inspect in there.
- 36:46So for those of you
- 36:47who,
- 36:48you know, don't know the
- 36:49rhinostics,
- 36:51the idea is
- 36:52that said in words, you
- 36:54could see what you treat
- 36:55and you could treat what
- 36:56you see.
- 36:57It is something that we
- 36:58don't often have the luxury
- 37:00of with chemotherapy
- 37:02where
- 37:03you don't see what you're
- 37:04treating. You you treat and
- 37:05then you're treating blind. So
- 37:06the idea basically is that
- 37:09we would use a PET
- 37:10agent, and we'll talk in
- 37:11a minute about agents, but
- 37:13that is going specifically to
- 37:14a tumor to see if
- 37:15you have enough signal
- 37:16to justify treatment,
- 37:18through a radiopharmaceutical
- 37:19treatment.
- 37:20If you do, then you
- 37:21have your radiopharmaceutical
- 37:22treatment, and Pam is doing
- 37:24a lot of this in
- 37:25NET.
- 37:26And then, at the end,
- 37:27you could even image and
- 37:28see how well have you
- 37:29done.
- 37:30That's the general idea.
- 37:32What we're interested in doing,
- 37:33and we're very excited, that's
- 37:34another project that we'll be
- 37:36starting,
- 37:37is that what you could
- 37:38do is not just
- 37:40do your
- 37:41pretreatment,
- 37:42in this case, Lutetium,
- 37:44and then Pam told me
- 37:45we've just done our first
- 37:46alpha last week.
- 37:48But for both of them,
- 37:49it's the same idea. You
- 37:50don't do your
- 37:52pretreatment imaging. You say, yes.
- 37:53There's enough uptake. Well
- 37:55and then we do our
- 37:56post treatment.
- 37:57We've done well. What we
- 37:59would like to do is
- 38:00after every treatment,
- 38:02image the patient to define
- 38:05how our targets are responding,
- 38:07what is our pharmacokinetics,
- 38:09and what is our effective
- 38:10dose. Because
- 38:11there are some patients where
- 38:12we will need to treat
- 38:13more. And there are some
- 38:15patients where
- 38:16we don't need at all
- 38:17the dose we're doing. We
- 38:18can go a lot lower
- 38:19and we still have the
- 38:20same effect.
- 38:21We have an opportunity to
- 38:22do what we've done always
- 38:23in iodine, for example, month
- 38:24thirty one, to do a
- 38:26a dosimetry
- 38:27on the fly as the
- 38:28patients are being,
- 38:30given their two hundred milli
- 38:32curiae of Lutetium.
- 38:33And there's no cost to
- 38:34it other than the imaging
- 38:35piece because they are having
- 38:37their Lutetium anyway. So that's
- 38:39the idea with, NET with
- 38:41the neuroendocrine tumors. You can
- 38:42do the same, and and
- 38:44you can define the refine
- 38:45this at every treatment. So
- 38:46So you can see cycle
- 38:47one, cycle two, and then
- 38:49you decide, well, you know,
- 38:50we we can stop now.
- 38:52Or, no, we're gonna have
- 38:52to go one more cycle
- 38:54as opposed to six cycles
- 38:55of two hundred manicures.
- 38:57You can do the same
- 38:58in, prostate with the prostate
- 39:00specific membrane antigen that we
- 39:01can image. We can do
- 39:03a gallium pre, and then
- 39:04we can look at those
- 39:06targets. What's the effective dose?
- 39:08Do we need to go
- 39:08up or down? And do
- 39:10that one, two cycles and
- 39:11then,
- 39:13and then stop.
- 39:14We can even go further.
- 39:17What we can do, actually,
- 39:18and this is the project
- 39:19that I said we're excited
- 39:20we're starting,
- 39:21is we could do pre
- 39:22imaging therapy
- 39:24and only have one or
- 39:25two of those scans, and
- 39:26that is enough to predict,
- 39:29you know,
- 39:30whether you should act,
- 39:34increase or decrease your dose
- 39:36and and predict your outcome
- 39:37from very few of those
- 39:39studies. You don't need the
- 39:40whole
- 39:41study to predict that. So
- 39:42the idea is gonna be
- 39:43to looking at the very
- 39:44early frames to very early
- 39:46treatments to predict that because
- 39:48more often than not, it
- 39:49it is something you can
- 39:50predict. It is challenging. It's
- 39:52not simple, but I think
- 39:52it's very valuable because,
- 39:55you know, when we talk
- 39:56about personalized medicine,
- 39:58this is
- 39:59personalized medicine by excellence. This
- 40:01is like, you know, you
- 40:01can't go more personalized than
- 40:02that. It is your scan
- 40:04that is defining your dose.
- 40:06I would like to leave
- 40:07you with two last slides
- 40:08on something that is a
- 40:09lot more, you know, also
- 40:11coming, down. This is work
- 40:13from Jason Kai who's looking
- 40:15at a similar approach for,
- 40:18prognostics
- 40:19but for gliomas. And this
- 40:20is looking at PARP.
- 40:23Those of you who work
- 40:23in PARP, you probably know
- 40:24that PARP one inhibitors
- 40:26are approved as treatment drugs
- 40:28in many cancers, breast, pancreatic,
- 40:30but also in brain. And
- 40:31the idea here is to
- 40:32label the PARP
- 40:33and
- 40:34see,
- 40:36and see if we can
- 40:37then use it for treatment.
- 40:39What Jason has done is
- 40:40the very first PARP
- 40:42brain penetrant tracer. There has
- 40:43been some that were not
- 40:44brain penetrant.
- 40:46Why that is important? Because
- 40:47if it's not brain penetrant,
- 40:48then you can't cross the
- 40:49blood brain barrier and the
- 40:50only time you see the
- 40:51tumor is when there's breakage.
- 40:52In this case, he has
- 40:53shown that in the intact
- 40:54brain barrier, you can image
- 40:56that,
- 40:57and see the tumor. And
- 40:58the idea, of course, is
- 40:59now well, he's done that
- 41:01first with c eleven because
- 41:02that's the easiest. Now we're
- 41:03doing it with f eighteen,
- 41:04and his plan is to
- 41:05do that with,
- 41:06acetylene,
- 41:07because then you can, do
- 41:09the same story. We we
- 41:10talked about with neuroendocrine
- 41:12and with
- 41:15prostate. Now you can do
- 41:16that in in the brain.
- 41:17So that would be
- 41:19a first.
- 41:20And, it's, optimistic, but he's
- 41:22hoping that in a year
- 41:24or two from now, his
- 41:24ID will be up and
- 41:25running.
- 41:26Alright. So,
- 41:27I was asked to finish
- 41:29with enough time for questions.
- 41:30I hope this gave you
- 41:32a good sense of what
- 41:33can PedamR do PedamR do
- 41:35for you.
- 41:37I do hope, you know,
- 41:38it gives you
- 41:40some appetite for for some
- 41:41of the imaging. I do
- 41:43believe that imaging is not
- 41:44meant to be just, you
- 41:45know, show and tell, but
- 41:46it has to guide the
- 41:47treatment. If imaging doesn't guide
- 41:49treatment,
- 41:50for me, it's, you know,
- 41:52a very,
- 41:53you know, frustrating.
- 41:55It's a nice exercise, but,
- 41:57when we can guide treatment,
- 41:58that's when we have a
- 41:59role, that is meaningful. So
- 42:00with that, I'd like to
- 42:01thank you for the kind
- 42:02invite to be here. And,
- 42:03if you have any questions,
- 42:04happy to take them.
- 42:13Questions from the room. And
- 42:15yes. Go ahead.
- 42:17Yeah. That's a thought. You
- 42:19talked about a lot of
- 42:19things. I was curious. What
- 42:22of of the things you
- 42:23talked about, where do you
- 42:24think you kinda where's the
- 42:25lowest hanging fruit? What do
- 42:26you think of this as
- 42:27the kind of most immediate
- 42:28potential to impact cancer care?
- 42:31When it comes back. What
- 42:32are you most excited about?
- 42:33I hate this question because
- 42:35each of those is one
- 42:35of my kids, and whichever
- 42:37I'm gonna say, a lot
- 42:38of others are gonna be
- 42:39upset. But,
- 42:43I do think that in
- 42:44the diagnostic space, there's a
- 42:46lot of room.
- 42:49I don't wanna sound pessimistic.
- 42:51We are behind
- 42:52we are behind the eyeball
- 42:53here.
- 42:55Most sites have already now,
- 42:58very active diagnostic sites,
- 43:00centers that are treating regularly
- 43:03hundreds of patients. That's one
- 43:04area of there's clear opportunity.
- 43:07I understand some of the
- 43:08caution of, well, you know,
- 43:09a lot of these patients
- 43:10recur, and that's right.
- 43:12But it is the
- 43:16you saw that example where,
- 43:17you know, we learned by
- 43:18by doing something, we realized,
- 43:20oh my god. There's monocytes
- 43:21being trafficked.
- 43:23You're not gonna do the
- 43:24alpha
- 43:25treatments. You're not gonna do
- 43:26the second generation
- 43:27if you don't have a
- 43:28site where you're doing a
- 43:29lot of those patients.
- 43:30So,
- 43:32it is one area clearly
- 43:33where there is
- 43:34a huge impact,
- 43:35for our patients. I understand
- 43:37for now it's only two
- 43:38cancers, not every cancer. But,
- 43:40again, if you don't have
- 43:41it for two, you're not
- 43:42gonna have it for ten.
- 43:43The other area I would
- 43:44say is the spectroscopy part
- 43:46because that is now very,
- 43:48mature.
- 43:49And, for the longest time,
- 43:50we didn't do it because
- 43:51it was too prohibitive in
- 43:52terms of imaging. If you
- 43:53need, you know, thirty minutes
- 43:54to scan in addition to
- 43:55everything you're doing in MR,
- 43:57nobody's gonna agree to it
- 43:58because spots are what they
- 44:00are. But eight minutes is
- 44:01feasible, and I think there's
- 44:02there's a role there.
- 44:04And I would say guiding
- 44:05the treatment is something that
- 44:07is very important because,
- 44:10you know, it it in
- 44:11in in no way it
- 44:12is meant to be, oh,
- 44:13well, no. You got it
- 44:15wrong. It is that a
- 44:16lot of times we don't
- 44:16see on the on the
- 44:17images
- 44:18as much as we should
- 44:19be. So I think the
- 44:21treatment guidance is one area
- 44:22that is promising.
- 44:40Good.
- 45:15That's right. So
- 45:16we do know that they
- 45:17are affected, actually,
- 45:19because, you know, if it's,
- 45:22if it's if if it's
- 45:23Farheem,
- 45:24you know,
- 45:25once it breaks down, it
- 45:27will be taken out in
- 45:28in anemia.
- 45:29But,
- 45:31but that core is not
- 45:33in the case of Fahraheem,
- 45:34that core is not broken
- 45:36for,
- 45:37over four hundred hours.
- 45:39So
- 45:41as long as we're imaging
- 45:42within the area,
- 45:44the time that we have
- 45:45validated our radio tracer,
- 45:47we are safe.
- 45:49What you can't assume and
- 45:50and to be clear, what
- 45:52you're injecting is picomolar.
- 45:54So from a physiological point
- 45:55of view, you're not gonna
- 45:56see any effect. It's just
- 45:57that your image after a
- 45:59while will not represent,
- 46:01the membrane potential or the,
- 46:04or the monocyte trafficking. It's
- 46:05just taken up,
- 46:07wherever there's iron,
- 46:08iron need. It's just over
- 46:10two hundred and fifty hours
- 46:11later. So you're that's where
- 46:13we would worry about it,
- 46:15but not in the not
- 46:16within the imaging time.
- 46:27Right. So we have there
- 46:29what we have done. And
- 46:30and for the member potential
- 46:31compound, I think I showed
- 46:32you some human studies. We
- 46:33have an IND. We've done
- 46:34first in human. We've done
- 46:35over thirty of them now.
- 46:36We have done
- 46:38the test retest in multiple
- 46:40patients on different days.
- 46:42And that's the curve I
- 46:44showed you, and I
- 46:45thank you, Harriet, for pointing
- 46:47this out. That's the curve
- 46:48I showed you where I
- 46:49said it's very constant.
- 46:52This was surprising for us
- 46:53because, you know, there is
- 46:54big variability when we do
- 46:55humans on different days.
- 46:57It is just that this
- 46:58is such a
- 46:59tightly regulated,
- 47:02physiological parameter that there was
- 47:04very little change. So we've
- 47:05we've tested that in but
- 47:07I mean, it's indirectly, obviously,
- 47:08but we've done that in
- 47:09test retest. And even when
- 47:10we did patients
- 47:12well, for now, the chronic
- 47:14is in pigs. When we
- 47:15did pigs over time, I
- 47:16showed you eight of those
- 47:17that have gone for six
- 47:18month,
- 47:19the areas that were not,
- 47:24when we did when we
- 47:25first did the
- 47:27the acute, the errors that
- 47:28were not affected on multiple
- 47:29times, that was the same.
- 47:31So that was that was
- 47:32reliable.
- 47:33The obviously, when we did
- 47:34the chronic, then the whole
- 47:35the whole heart, then myocardium
- 47:37was affected because this is
- 47:38somatic IV injection.
- 48:10Yes.
- 48:17I would say yes. So
- 48:19thank you. That's not good.
- 48:20Another nice plug in. So
- 48:22we have a Panama coming
- 48:23in.
- 48:26Let me I did mine.
- 48:28We have a Panama coming
- 48:30in
- 48:31in
- 48:33q three
- 48:34twenty twenty six
- 48:36on the so
- 48:38I know it sounds long
- 48:39from now, but I'm told,
- 48:41you know, in the old
- 48:41timelines, that's very fast.
- 48:44I've been here eleven months,
- 48:45so I've I've learned enough
- 48:47now. It's
- 48:48so this is a research
- 48:50scanner
- 48:51that we are working hard
- 48:53on
- 48:54making one day available
- 48:56for clinical work.
- 48:58The same way we have
- 48:59a seven Tesla coming in.
- 49:00We're there. We have now
- 49:02the agreement that two days
- 49:03a week will be available
- 49:04for
- 49:05clinical. I'm very keen on
- 49:07on sharing these because
- 49:10the seven Tesla would be
- 49:11two days for clinical.
- 49:13So I hope we'll be
- 49:15able to do the same
- 49:16on the Panama side
- 49:18because I'm I'm putting my
- 49:19money where my mouth is.
- 49:20I mean, what's the point
- 49:21of doing all this if
- 49:22you can't see it? The
- 49:23idea being that, you know,
- 49:24if we do one day
- 49:25a week and we see
- 49:26a huge value, like you're
- 49:27saying, well, then that would
- 49:28justify that would give us
- 49:29the argument for having more
- 49:31of those installed clinically.
- 49:33That's how we've done at
- 49:34Pest General before. We we
- 49:35started with a research one,
- 49:36and then at one point,
- 49:38surgeons refused to go in
- 49:39unless they had the PET
- 49:40and the MR. And it
- 49:41was like, okay. Well, now
- 49:42we're gonna have one clinical.
- 49:43Can I ask the question?
- 49:45Of course.
- 49:47So a a question as
- 49:48it relates to quantitative imaging
- 49:50for clinical trials.
- 49:51So I think as we're
- 49:53getting better and better resolution,
- 49:54especially with the sort of
- 49:56PET MR, we're really stuck
- 49:58as it relates to quantitative
- 50:00imaging, especially as it relates
- 50:01to even our new diagnostic
- 50:02trials where we're we have
- 50:04to use RECIST, which is
- 50:05based just on
- 50:07cross sectional imaging. Do you
- 50:08have any thoughts on sort
- 50:10of the evolution of that
- 50:11field and where we should
- 50:12be going?
- 50:14Yes. I think resist is
- 50:15a heresy in the age
- 50:17of the diagnostics because
- 50:19what you're measuring is
- 50:21if you think ejection fraction
- 50:24is too late compared to
- 50:25membrane potential for the canary
- 50:26in the mine,
- 50:28This is you know, that
- 50:29that tumor is not gonna
- 50:31shrink for months before I
- 50:32mean, this is not at
- 50:33all useful.
- 50:35What I showed in the
- 50:36case of the,
- 50:38NET and and prostate
- 50:40is a full model, a
- 50:41full dosimetry. We can do
- 50:43that now.
- 50:44The challenge is that currently,
- 50:46if we were to do
- 50:46this I mean, Larry would
- 50:48love to do this every
- 50:49day. But on his spec
- 50:50scanning, it would take him
- 50:51an hour and a half,
- 50:52an hour to do that
- 50:54full survey.
- 50:56But there are scanners available
- 50:57today that are
- 50:59full ring spec systems where
- 51:00you can do in ten
- 51:01minutes what you do in
- 51:02an hour and a half.
- 51:04And,
- 51:05we also are planning on
- 51:06installing one, and we're hoping
- 51:07that will be one also
- 51:08on the clinical side. And
- 51:10there, what you do is
- 51:11just a simple survey,
- 51:12a ten, twenty minute, but
- 51:14every time.
- 51:15And as you do that,
- 51:16then you can see your
- 51:17residency time of your tracer.
- 51:19You can quantify your effective
- 51:21dose, which is a lot
- 51:22more I mean, that's what
- 51:24people have been doing for
- 51:25ages in in I one
- 51:26thirty one when they needed
- 51:27to quantify,
- 51:29how much can you give
- 51:30somebody who's coming back after
- 51:32recurrence.
- 51:32This is
- 51:34there's nothing there. I wish
- 51:35I could say, oh, this
- 51:36is groundbreaking and very novel.
- 51:38This is standard,
- 51:40and we can do it
- 51:40tomorrow if we had,
- 51:43We just need a clinical
- 51:44trial to catch up. Correct.
- 51:45Oh, absolutely. So this is
- 51:45available well well, you know,
- 51:46well I mean, it's
- 51:49there's
- 51:50nothing
- 51:51there that is
- 51:55very novel. It is just
- 51:57that for most trials, we
- 51:58we just cut corners and
- 51:59say, yeah. Let's look at
- 52:00resist, but it's there. It's
- 52:01available. And we can do
- 52:02it. And in the past
- 52:03center, we can do that
- 52:04for any of those trials.
- 52:06Question about AI, which you
- 52:08talked a little bit about.
- 52:10In lung cancer, for example,
- 52:11there's a civil, which is
- 52:13a way of using AI
- 52:14to look at,
- 52:16low dose screening, and and
- 52:18sometimes it's more effective than
- 52:20than, our current methods. So
- 52:22and you talked a little
- 52:23bit about, you know, standardizing
- 52:25and the the inter
- 52:27you know, different
- 52:29Inter observer availability. Yes.
- 52:33I think it's gonna go.
- 52:34Is this something where AI
- 52:36is gonna help
- 52:37be more accurate, be more
- 52:38better? Is it gonna actually
- 52:41be able to replace some
- 52:42of those radiologists
- 52:44so that you can get
- 52:45to,
- 52:46you know, different places in
- 52:47rural communities?
- 52:48Where do you think AI
- 52:49is is, is gonna
- 52:52I was recently at a
- 52:53talk in surgery. Don't ask
- 52:54why, but it's surgery talk
- 52:56for a surgeon who only
- 52:58does surgery in the middle
- 52:59of this the toxic and
- 53:00here's my slide for AI
- 53:01because you have to have
- 53:02one. And I was like,
- 53:04wow.
- 53:04If surgery is now in,
- 53:06then we're good.
- 53:07I think it's not a
- 53:08question of if. It's a
- 53:09question of when. It's happening.
- 53:11It is AI is taking
- 53:12over a lot of what
- 53:13we're doing.
- 53:14The reason why you notice
- 53:15I'm very careful in what
- 53:16I'm showing
- 53:18is because we are doing
- 53:19a lot of deep learning,
- 53:20and there are
- 53:21what we call case of
- 53:22hallucination where
- 53:24every now and then you
- 53:25get a case that doesn't
- 53:26make any sense.
- 53:28And our biggest worry is
- 53:29that and this is why
- 53:31I was very careful saying
- 53:33this is an aid
- 53:34as somebody's starting to use.
- 53:37The big worry from many
- 53:39of the ethicists right now
- 53:40is that as the physician
- 53:42relies more and more on
- 53:43the on the tool, they
- 53:45become more and more different
- 53:47to the tool. And when
- 53:48sometimes they feel like, oh,
- 53:49I'm not sure, but, oh,
- 53:50but think that I'm it
- 53:52must be true. And and
- 53:54you're still liable.
- 53:55You're still responsible. So I
- 53:57would have a word of
- 53:58caution that,
- 53:59yes, it is happening, but
- 54:00I I don't see it
- 54:03as the the panacea because
- 54:06until we have such volumes
- 54:08of data, which we don't
- 54:09have today,
- 54:10that any case we're gonna
- 54:12see has been seen before.
- 54:17I'm I'm sorry. I'm not
- 54:18as enthusiastic as I was
- 54:20about everything else I talked
- 54:21about, but that's because we
- 54:22do a lot of deep
- 54:23learning in our we do
- 54:24a lot of it, and
- 54:26we see limitations.
- 54:27So because of the limited
- 54:28data we have, we don't
- 54:30have
- 54:31the data that Facebook has.
- 54:32We don't have a billion
- 54:34paths.
- 54:35I mean, we don't have
- 54:36a billion CTs, let alone
- 54:37a billion paths.
- 54:40We we probably need to
- 54:41end if others have questions,
- 54:43maybe come up afterwards, but
- 54:44we're at time that