Simon Cherry, PhD: "A Matter of Time"

This episode features Simon Cherry, PhD, discussing his recent 2022 Annual Meeting Cassen Award Lecture and more in a wide-ranging conversation with SNMMI President, Munir Ghesani, MD.

In his lecture—A Matter of Time—at the SNMMI 2022 Annual Meeting, Cassen Award Winner Simon Cherry, PhD , explored time, and its role in nuclear medicine, from historical developments occurring over decades, to technologies that can detect photons with a precision of tens of picoseconds. Inspired by the groundbreaking ideas of Benedict Cassen and others, Dr. Cherry charted the journey from the past and into the future to create the ultimate imaging devices for studying the body and its many interacting systems

The Benedict Cassen Prize is awarded by the Education and Research Foundation (ERF) for Nuclear Medicine and Molecular Imaging in recognition of outstanding achievement and work leading to a major advance in nuclear medicine science.

Transcript

 | ANNOUNCER - V/O: RUNS: 17 SECONDS The Society of Nuclear Medicine and Molecular Imaging welcomes you to the SNMMI Podcast Series – focusing on deep dives into hot topics for nuclear medicine and molecular imaging professionals, and featuring findings and anecdotes from some of the preeminent thought leaders in the profession.

| DR. GHESANI 28:22 - 29:09 RUNS: 67 SECONDS Welcome to the latest episode of the SNMMI Podcast Series. I'm SNMMI. President Munir Ghesani. Today I'm honored to speak with Dr. Simon Cherry professor of biomedical engineering, and radiology at UC Davis.  At the recent SNMMI annual meeting, we welcomed Dr. Cherry as our Cassen lecture, where he gave an impassioned speech exploring time and its role in nuclear medicine. From the historical developments occurring over decades, to the acceleration of new technologies that can detect photons with a temporal resolution of tens of picoseconds. It was such an inspiring talk that we wanted to continue the conversation.  Dr. Cherry, welcome. And thanks for joining me.

| DR. CHERRY 1:19 - 1:22 RUNS: 4 SECONDS Munir is a great pleasure to be with you today.

| DR. GHESANI 1:24 - 1:33 RUNS: 9 SECONDS Could you expand on your theme about time which you had multiple meanings in your Cassen lecture and you referenced several times during that lecture?

| DR. CHERRY 1:33 - 3:47 RUNS: 134 SECONDS Yeah, so I've always been fascinated by time, you know, I was a physics undergraduate. And I always remember that perhaps the most exciting thing I learned during my undergraduate degree was about the theory of relativity and how time is not constant. And there's also the human perception of time, right? We all know that we don't experience time in a constant fashion. Any sports fan knows that if their team, is winning, with just a few seconds left, those seconds seem like an eternity.  So I've always been fascinated by time. But of course, it's very central to our field as well, because the image that we get after we inject a radiotracer depends absolutely on the time that take that image and the distribution of that radiotracer evolves in the in the body over time, and we perhaps don't take as much advantage of that always as we might. And then, of course, the final piece of time in our field is Time-of-Flight PET, where we're now talking about timescales on the order of tens, or hundreds of picoseconds. So incredibly, incredibly small timescales, where we measure the difference in arrival time of the of the two photons that we detect in PET, in order to better localize where the signals coming from, and my lab is very involved in trying to develop next generation technology that can push that timing resolution, closer and closer to the point where it will be good enough. If we can get down to 20, 30 picoseconds or so that we can actually directly generate an image without going through the image reconstruction step. And that's sort of the ultimate Holy Grail, I think, as a imaging physicist in our field is to get to that point where we create PET images. With no image reconstruction, we know exactly where the events are coming from. And that should lead to some pretty spectacular images with great spatial resolution, great temporal resolution, all kinds of interesting opportunities initially in research and hopefully in the end, developing new clinical applications as well.

| DR. GHESANI 3:47 - 4:28 RUNS: 41 SECONDS This is, quite enlightening. The question I have, which is, I'm sure in the minds of many in the audience. Listening to this is that this opens up the door in so many new areas and applications in neurology, oncology, cardiology and beyond. But in your own opinion, where do you think in the next five to 10 years, the maximum promise of this is going to be, which is an instant success. In your own mind? Where do you think these key advantages are going to be in the future?

| DR. CHERRY 4:28 - 6:13 RUNS: 105 SECONDS It's always hard to predict the future, right, the dangerous thing to do. But, I mean, obviously, nuclear medicine has been incredibly successful in oncology. And so the question is, how do we take that paradigm and repeat that in some other areas and what are the most promising areas so sure, now we have, PET scanners with these extended fields of view where we can image large fractions of the total body all at once, and we can do that with really good signal to noise. You know, I think the obvious here is you should think about your already mentioned cardiovascular applications. So we can see the entire cardiovascular system at once. And then I think the other obvious area, given what we've just been through in the world in the last three years, is in infectious disease. I think the, the intersection of these new imaging technologies with really good sensitivity and large coverage across the body, with new radio traces that can target specific aspects of the immune system. So I'm thinking of traces, for example, that combined the T cells, I think, gives us a huge opportunity in infectious disease. You initially practice more in the research area to really understand if we take COVID-19 as an example, you know, the evolution of the disease interventions, effects of vaccination and boosters, long COVID is an obvious area for us to study and to really be able to see what's happening with the immune system longitudinally in these patients. So I think there are many opportunities, and there are probably many, I'm not even thinking about right now that the other people listening in will be thinking about.

| DR. GHESANI 6:16 - 6:46 RUNS: 30 SECONDS Having discussed that part about the future promise and you're absolutely correct, the future is hard to predict. But knowing where the promises are going to be in the future, I clearly see the value as you mentioned, in addition to oncology and cardiovascular in the infection and immune system, if we were to accomplish all of those goals, where do you see the biggest barriers in achieving those goals in the near term?

| DR. CHERRY 6:46 - 9:47 RUNS: 181 SECONDS I think one of our biggest barriers is our workforce. I think we, have so many opportunities, but I think we'll, we're lacking enough people to really drive those opportunities forwards. And I'm thinking particularly about physician scientists, who are going to be key to developing applications and really asking the right questions initially in the research setting that ultimately could have clinical impact. So I just know, as I talk to colleagues across the world, really, that it's finding those people that work at the intersection of our field and medical specialties that will devote their lives to developing these applications and these approaches, and validating them. That I think is crucial. Andthere's good examples of people out there doing this, but there's relatively few of them. So I guess my biggest concern is how do we train the next generation of physicians and physician scientists and attract them to our field, get them really excited about the future, which I think for nuclear medicine is incredibly bright.  And we haven't touched on therapy yet. But obviously, that's a massive, massive growth area, in our field. So I think, you know, theranostics, combined with these really advanced imaging systems, gives us incredible opportunities. But we can only realize, though, is if we have a critical mass of people. And so I think that that's one of the biggest barriers. And then I think the other barrier is perhaps sometimes we think, a little bit too small in our field, we need to be ambitious, we need to push at all levels. We've been criticized a little bit for generating this very expensive total body imaging technology. And yes, it is expensive, but it opens up opportunities and possibilities that things you just couldn't do before. And there will be a trickle down effect, no doubt that there are things that we will discover that can be applied back to the conventional PET scanners as well. So I think you need to push in all directions at once. We need to push at the high end, continue to develop the technology and not be shy about doing that. Although that does come with cost implications. Hopefully that will improve over time, our regular technology and its applications as well. We need to push on the application side, we need to push on demanding more quantification. Yeah, we have a very quantitative tool, but we don't use it that way very often. And so I think we can do better in that regard as well. But most of all, we just need the next generation of enthusiastic young talent. And how we attract those people I think is something that all of us in the field are thinking about.

| DR. GHESANI 9:50 - 10:41 RUNS: 51 SECONDS You mentioned about the future workforce as you are probably aware that SNMMI has one of the target areas of workforce pipeline that it is addressing on three different levels. One is for the physicians, the other one is for the technologists, and the third one is for the scientists. Now these are traditional domains based on what you just mentioned about the future and diseases who will be taking the field to the next level and based on the promises of very fine temporal resolution and other things that are coming out of the developments. Are there any other areas besides these three traditional buckets that we think about where you will see future needs of workforce pipeline that need to be met to move the field forward?

| DR. CHERRY 10:41 - 12:51 RUNS: 130 SECONDS Well, I think that that encompasses the key areas, but I think it's perhaps the intersection with other, you're particularly talking about the physicians intersection with other medical discipline.  If we take the example of, imaging the immune system, I mean, immunology is incredibly complicated. I, as a physicist, barely understand the first thing about it. But what I have come to appreciate as we've been doing studies and COVID-19, is just how incredibly complex it is. And so we need people that really understand this to be engaged. And at the same time, they've got to understand enough about imaging as well and nuclear medicine and what we can do to be able to ask the right questions thatwe can address with our technology and methods. So it's that sort of communication and how we build teams that bring together the different expertise. And as you rightly point out, those teams need to involve all three of those pillars.  You need the physicians who are going to ask the right questions, you're the technologists, a key to implementing high quality, robust, reliable imaging, and also really making the patient experience everything that it needs to be. And then on the scientific side, we need a range of different disciplines, obviously, where we're designing more and more specific radio traces, we still have great needs in that area. So radio chemists and chemists are really important. People that understand the fundamental biology are important to the team, as physicists, and engineers, who will hopefully make our techniques evermore quantitative and robust. And so we need to build these coalitions. And we need to have many centers that have these teams working together. And you see good examples of this already, but we need more of it. And we need it in some of the less traditional areas outside of oncology.

| DR. GHESANI 12:53 - 13:10 RUNS: 17 SECONDS It looks like we collectively as nuclear medicine physicians, the technologist as well as the scientists will have to start collaborating with multiple other specialties that stand to benefit the most with this promise of new technologies that are evolving.

| DR. CHERRY 13:10 - 14:09 RUNS: 59 SECONDS Yeah, that's the way I see it. And the key is identifying, you know, the people in these other areas that are willing to take the time to invest in us as well, it goes both ways, right, we need to invest them and they need to invest in us and, and how we get more of an awareness of what our field is capable of. But beyond what we do clinically, which is already great.  I think, getting people aware of what we can do at the high end of research to really contribute knowledge across different medical disciplines. We draw top people from different fields in to our field as well. I think that's what we have to do is we have to get out to the other societies, we have to get out to these other meetings. And we have to promote what we're capable of doing, which is quite astonishing. If you compare where we were, you know, 20, 30 years ago, it's incredible what we can do in nuclear medicine today. And again, not just on the imaging side, but increasingly on the therapeutic side as well.

| DR. GHESANI 14:09- 14:25 RUNS: 16 SECONDS Now these have been few crazy years living through the pandemic. How have you navigated the challenges both personally and professionally? And do you think the pandemic has slowed down or reduced the amount of research happening in our field?

| DR. CHERRY 14:25 - 17:11 RUNS: 166 SECONDS It's obviously been tougher for pretty much everybody and in different ways. You know, I think there are relatively few people for whom this has been a good thing, I would say. It's certainly slowed down research. I mean, many research institutions, were partially or completely shut down for a while, , including ours. So it certainly slowed things down. But I think the biggest cost in science has been the human interaction, you know, the lack of the ability to get together to exchange ideas, to go to conferences. And I think we will always knew that that was important. But I have a much, heightened appreciation for that now having been through this period of what I’ll  call isolation, and having just started to go back to conferences, getting I mean, having just been in Vancouver for the SNMMI annual meeting, it was just fantastic to see people again, and so many side conversations that just don't happen in a virtual conference that really, you know, lead to new collaborations, new ideas, and this is what it's all about.  And so I think, we've all suffered through the lack of interaction, and even locally with our own lab, the inability for the grad students and the postdocs and the residents and the physicians to be getting together every week and chatting, and having Journal Club and lab meetings. And, just doing it virtually is not a replacement. So. It's certainly been a struggle, but now that we're sort of beginning to emerge from it, I think everybody has a much greater appreciation for what we had before. And so maybe that's a good thing that we will cherish that even more.  And then I think we also have to address the whole work-life balance working from home, working from the office, working in the lab, how that's gonna look in the future. I think we've all seen that we can be effective in different ways. And for different people, it looks how that looks, we'll be different. You know, it's one thing to work from home, if you've got young kids at home, versus if you're alone in your home, you know, you can be perhaps pretty effective if nobody else is around, and it's nice and quiet. But, for many people with families, this was an exceptionally hard time to try and balance the family responsibilities, and the work responsibilities.  I think how we reimagine the workplace, to make it the best it can be for everybody to encourage the interactions, which is so important, as I just mentioned, but also give people the flexibility so that they can maximize their efficiency and productivity. I think that's another challenge that we're all thinking about.

| DR. GHESANI 17:11 - 18:22 RUNS: 71 SECONDS Yeah, that brings up an interesting concept of the work life balance and what do you compromise by giving more flexibility by working at home. And I know a couple of companies recently have put out a mandate that you have to spend all 40 hours in person. There are others. For example, my son's company has a very creative concept that you work from home on Mondays and Fridays, but you need to be at work Tuesdays and Thursdays so you can collaborate, come network come up with the new ideas as a team.  I suppose these are some of the concepts that will come through for a radiologist to read the scans at home, it doesn't make much of a difference. But for a lab that's always thinking of innovative ideas. Doing so at home can clearly compromise as you stated very well. So you think that in the future for labs, this will be potentially a balance where there'll be some flexibility for working from home but there will be some minimum required time for people to collaborate on site at work right?

| DR. CHERRY 18:22 - 19:50 RUNS: 88 SECONDS It's hard to think what the optimal solution is. And I think the problem is that it very much depends on the job responsibilities, as you just pointed out, and on the individual's circumstances. So I think that the challenge is,if you want to be prescriptive, and have a certain set of rules, they're probably not going to work well for everybody, if you can be more flexible. And trust that people will do the best they can, then you may get more more out of people that way, and they may be more effective and efficient.  So I'm trying within our environment to listen to what everybody's needs are and to think about how we achieve two things, which is one foster community, because it's so important. And at the same time, allow people some flexibility, so that they can work in the manner which they think is most efficient. And perhaps in research, we're a little lucky we've always had that flexibility to a certain extent. I mean, I've always had people in the lab that are late night people, for example. So they won't show up particularly early in the morning, but you know, they'll be there 10, 11, 12 o'clock at night. And then we have other people that are morning people in love to get in early before it gets busy. And then they have access to everything in the lab before other people get there. And so we've always had that sort of flexibility. So why can't we extend that a bit more?

| DR. GHESANI 19:54 - 20:02 RUNS: 8 SECONDS You are a role model to so many of us in our profession. Can you tell me a little bit about Who influenced you along your way?

| DR. CHERRY 20:02 - 22:41 RUNS: 159 SECONDS My gosh, that's a difficult question. Because there's so many. I mean, I think one of the great things about the career I've had is all the wonderful people I've been able to interact with over the years and, and essentially you learn something from every interaction with somebody.  So you know, I can easily list hundreds of people that have influenced me, of course, to go back to your key mentors, right, your PhD mentors who were Bob Huddart and Maggie Flower, and in my case at the Royal Marsden Hospital in London. And then my postdoc advisor, Ed Hoffman, at UCLA were very key figures, because they spent a lot of time helping me and teaching me. So that was, those were key figures. But there's many more besides that, you know, I've had the opportunity to interact with so many great people in our field over the years.  And I've always been impressed by the generosity, the time that people take, almost without exception, we've had some wonderful people, leaders in our field over the years, you know, think of Henry Wagner, of course, you know, I enjoyed many conversations with him. And he always had time, even though he’s an incredibly busy man. And so been one of the joys of working in our field that I truly believe it's been very collaborative, very supportive. I've always felt supported by people in the field. And I've always learned, and I continue to learn, I still learn, it's not just the senior people, I learn a lot from my students. And I enjoy that very much. And so I think that, again, coming back to what we were just talking about, these connections are so important. That's how you learn. That's how you progress, you bounce ideas off people, you hear people presenting their work, and that gives you ideas. This is so important. And I think the important thing I want to say is that we're so much better as I feel when we collaborate than when we compete. And so I think that's what I've always learned, that the more that we collaborate with people, the more we open up and work together, the more we can achieve.  And the Explorer project, developing the total body scanner was a good example of that we had to work with a lot of people to make that happen. And we had key contributions from so many people, both in academia and in industry, and of course, eventually from the funding agencies as well. So it takes a team to do these things and collaboration is key.

| DR. GHESANI 22:41 - 23:26 RUNS: 45 SECONDS I fully agree with you and then you as you touched upon the collaboration, our earlier conversations about reaching out of our traditional domains and reaching out to infectious disease specialists, going out to the immunologists to maximize our understanding of these complex systems is going to be the key to move our field forward in the future.  And now, you are getting involved more and more into multiple projects and it must be keeping you so busy. So what do you do to do get some kind of stress relief? What are some of your downtime activities? Not that you have so much downtime.

| DR. CHERRY 23:26 - 25:04 RUNS: 98 SECONDS No, actually, I try really hard on the work life balance, because I think it's so important. And usually I can do my best work if I'm not stressed. And if I have a good work life balance. So that's always been important to me during my career.  Of course, family is key, I have four kids, I adore them. And so, you know, spending time with family is very important to me. I have other interests as well. So I'm a piano player, not a very good piano player, but I love to play. And being British, I love to garden as well. So we're just enjoying hundreds of peaches off our peach tree right now. And so those are some of the ways that I relax.  And, I encourage all of our team members to make sure they take time away from work because that changing environment and different stimulation, I think is what allows ideas to come and the energy then to pursue those ideas. So I think, you know, it's very important that we find ways to balance, the long hours and the stress at work that is almost inevitable in our profession with a healthy amount of downtime, other opportunities to pursue interests, vacations. I was lucky my parents always insisted on a vacation every summer where the whole family would go and that's a tradition I've tried to carry on in our family too. I think that's really key. So yes, absolutely work life balance really important.

| DR. GHESANI 25:04 - 25:26 RUNS: 22 SECONDS Well said Simon.  And that importance is going to be even more critical in the future until we find more workforce pipeline solutions where individually we all will have to contribute more to continue to move the field forward. So the work life balance is going to be more and more critical in the coming years.

| DR. CHERRY 25:26 - 26:25 RUNS: 59 SECONDS I think, you know, one of the things we have to focus on is not working more, but working more efficiently, I think we have to ask ourselves the question, the things that we do during the day, how many of those are really important and really helping move things forward. And some of the things we do are very important. Obviously, things around patient care, things around teaching and mentoring are really important. And then any of us that are in an academic institution with lots of committees, noses, a lot of other things that really are not great value for time. And so, we should put our effort proportionately into the things that are most important. And that's one thing I've always tried to do, rather than extend the working day, to very long hours is just try to spend my time during the day on the important things and give much less time to things that  you know are not all that important

| DR. GHESANI 26:25 - 26:35 RUNS: 10 SECONDS And with that regard, I guess some of the repetitive tasks that we do, we can look forward to AI providing more solutions so that we can focus on more constructive activities.

| DR. CHERRY 26:35 - 27:26 RUNS: 51 SECONDS It's gonna be fascinating to see where, where this, this takes us, right? I mean, there’s so much excitement about AI right now, and rightly so because the opportunities are incredible. But of course, we're sort of in the honeymoon phase, right, where people think AI is gonna solve everything and it won't, and it will not replace many of the things that we need to do but it will assist and I think that's exactly the point you were making, but it will assist us, it will take away some of the easy redundant tasks that I think can be well tackled through AI approaches, and allow us to focus on the things where we really need our expertise and so that will hopefully improve the quality of our jobs and that’s a good thing.

| DR. GHESANI 27:26 - 27:47 RUNS: 21 SECONDS Yeah, absolutely. We all look forward to those solutions.  So, that's the wrap up for today's podcast. I would like to thank again, our special guest, Dr. Simon Cherry. For a truly engaging conversation. I can't wait to hear what's next. And thank you for turning into the SNMMI Podcast Series. I'm Munir Ghesani. Have a great day everyone. Thank you

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 | ANNOUNCER - V/O: RUNS: 11 SECONDS This has been SNMMI Podcast Series. Keep an eye out for future episodes where we’ll continue to tackle hot-button issues in the Nuclear Medicine and Molecular Imaging profession. Thanks for listening.