Setting a Global Standard: Unveiling the New PSMA PET/CT Procedure Guideline - Wolfgang Fendler & Ken Herrmann

June 12, 2023

Philip Koo discusses the newly updated PSMA PET/CT: Joint EANM, SNMMI procedure guideline, version 2.0, with its first and senior authors, Wolfgang Fendler and Ken Herrmann from Germany. The updated guideline, considered a landmark paper, integrates new ligands and types of imaging, consolidating information on PSMA imaging for different ligands and formalizing them as a class of ligands. It features standardized reporting and assessment of response to treatment, a significant step towards broader clinical implementation. As PSMA PET is now the standard imaging for many stages of prostate cancer, Fendler and Herrmann talk about their future aim to enhance PSMA PET's role as a predictive biomarker. They also hope to achieve standardization in PSMA PET reporting globally in the next few years.


Wolfgang Fendler, MD, Department of Nuclear Medicine, University of Duisburg-Essen and German Cancer Consortium (DKTK), University Hospital Essen, Essen, Germany

Ken Herrmann, MD, MBA, Professor and Chair of the Department of Nuclear Medicine, Universitätsklinikum Essen, Essen, Germany

Phillip J. Koo, MD, Division Chief of Diagnostic Imaging at the Banner MD Anderson Cancer Center in Arizona.

Read the Full Video Transcript

Phillip Koo: Hi, my name is Philip Koo, and welcome to UroToday. Today, we have a very special segment, where we're going to discuss the new PSMA PET/CT:Joint EANM, SNMMI procedure guideline for PSMA, and it's version 2.0. And to discuss this, we have the first and senior authors of this paper, who make up the SN team from Germany, Dr. Wolfgang Fendler and Dr. Ken Herrmann, who are both very familiar to us. So thank you guys for joining us today.

Wolfgang Fender: Thank you for having us.

Ken Herrmann: It's a pleasure to be here.

Phillip Koo: Great. So it's a landmark paper. I think it's a great way to sort of kick off the New Year. Can you tell us a little bit about what makes this manuscript so special?

Ken Herrmann: Maybe I start off by saying that, a couple of years ago, when I was already part of the EANM Oncology Committee and we decided to use actually PSMA imaging quite a bit in Europe, we figured we get a lot of questions how to do it, when to do it. We decided probably it's way too early to come up with the clinical guideline, but maybe it's a way that we put together as many people from different centers as possible to agree on a framework on how to use PSMA PET. And this was, and please correct me, I think, 2017, 2018, when this was published.

And we decided now that, obviously PSMA has progressed, PSMA PET has progressed, as part of clinical guidelines, we now have a couple of approved PSMA PET tracers, not only guidelines 68 but also through 18, that it is time actually to combine them. And this is when, again, me, as a chair of the EANM Oncology Committee, I needed someone to do the hard work and actually put this work together. And I was lucky enough to have the opportunity to reach out to Wolfgang. And maybe Wolfgang, you tell us a little bit, what was a big change of bringing now actually a class of imaging guidelines?

Wolfgang Fender: Yeah, I totally agree. I also see the specialty, or what is special about the guideline is the broad data and the broad background that we currently have, but which is also a challenge in a way to form these guidelines. So we have so much data on imaging on PSMA imaging for different ligands that we had to implement and combine. And the way we try to approach this challenge is to find a way that we formalize them as a common class of ligands. So we propose them to be kind of equivalent or equal, in terms of their diagnostic properties, with some specialties in their pitfalls and interpretations.

It's like different juices have different taste, but in the end, they kind of all work for imaging. And I think the second challenge is, of course, is it was a joint work of two societies of many authors to bring everyone together and to find common statements, to agree on common statements. In the end, I think it worked out very well to have common recommendations of two societies and 27 authors on those ligands. And I think the authors and the teams did a great job to approach this guideline.

Phillip Koo: That's a monumental task when you talk about 27 authors and two of the sort of long-standing societies with nuclear medicine. It's pretty amazing, and it takes great leadership. So thank you guys. So Wolfgang, maybe you could sort of talk to us about some of the differences in this version 2.0 versus the original paper, a few years ago.

Wolfgang Fender: So there was a huge need, practical need for us to make an update. And this came from new ligands and new types of imaging that were available. Those were the F18 ligands. So they are more practical. They have been used especially in Europe, but also more often in the US now. And we had to implement them in the new guideline. They have not been part of the first one, but we had to implement them and make recommendations. And this was really one of the major updates that we increased from few ligands from few gallium imaging to five candidate imaging ligands, including F18, and to make recommendations that kind of work for all of these ligands together.

And this includes, of course, recommendations to how to apply the imaging, how to perform the imaging, how to make interpretations and understand different pitfalls, different varieties on how to look on these images, but also, to report on background information, like dissymmetry for these different ligands. And I think that one of our key concepts really was to term these to summarize these as a class of imaging, so to say PSMA PET is a class of imaging that stands for itself as a high quality and a highly accurate PET imaging for prostate cancer. And then, there are different nuances and different subvariants that we need to talk about in this guideline.

Phillip Koo: So Ken, maybe I'll start with you. When I think about this paper, I think of it as a landmark level setting type of paper, that'll really help us, whether it's in the diagnostic world or the therapeutic world, that obviously we're getting deep into. Your thoughts on how this sets us up, especially with the focus on therapy?

Ken Herrmann: So as you know, there are two different guidelines. We have the imaging procedure guideline, and we have the therapy procedure guideline. You won't be surprised to tell you that the therapy procedure guideline is pretty much written together, and we expect it to be published latest in Q2 this year. I think the important part of this guideline really is that, and you mentioned 27 authors for many different countries, and we try to establish common ground. Same as with the EU and the European Union. If you put 27 people together, it's never the best solution, when you put things together. It's really the solution which everyone was willing to agree on. And the reason I like this guideline so much is because it really helps people, who do not have as much experience, for example, as our colleagues in the US or in many parts of Europe do.

It helps them to understand how to do this, not to repeat the same mistakes we have done. We have a big chapter actually addressing pitfalls, which I think is very important too. And it sets the standard actually for the next step of what I like to call evolution. Because now that we have agreed on how to use the PSMA PET imaging, the class of PSMA PET imaging, we have now to agree on the future on how to report it, on how to report response to treatment, and how to standardize everything.

And I think this was a purpose, not the aim of the guideline, to combine all the different reporting mechanisms, but really come with a very small but very focused common denominator and say "this is now set in stone." And in the next step, we need to actually initiate a procedure, where we bring all together the different kind of reporting standards, like primary PSMA ARAMIS, PROMISE, E-PROMISE, E-PSMA, PCWG3, and put them all together and actually set a framework and agree on how to standard in the future if you not only perform PSMA everywhere the same, but also report PSMA PET everywhere, at least in a similar fashion.

Phillip Koo: That's great. Wolfgang, any other thoughts here? You touched upon some of the novel aspects of this paper, any other details you'd want to shed light on?

Wolfgang Fender: Yeah, I agree on the outreach of the guideline, on the connections. It really sets the stage in many important topics. For example, for treatment, of course, there will be an own guidelines on how to perform, when to perform treatment, but we already recommend and we already talk about how to apply imaging to make an indication for the PSMA therapy. So this is kind of a part of the guideline that makes a connection towards treatment. And the other larger topic that has now been introduced in the novel guideline is, as Ken already mentioned, is standardized reporting, but also standardized assessment of response to treatment. So this is touched by the guideline. It's making recommendations, it talks about different frameworks that can be used, and I think this can be a connection to more thorough recommendations and work on how to really implement this in clinical studies, for example. And so, this is kind of setting the stage for increasing the topics and also making connections to other broader topics for PSMA PET imaging.

Phillip Koo: Wonderful. So your team, at Essen, real powerhouses, made so many contributions globally to this PSMA space. What's next? Help shed some light on where we're headed to next, and then, maybe, Wolfgang, I'll start with you. And Ken, I'll turn it over to you after that.

Wolfgang Fender: So I really believe that one important topic now is to really catch most of the aspects of broad clinical implementation. So a couple of years back, when we wrote the first guideline, there was still PSMA PETs versus conventional imaging. But now, with all the new evidence and randomized trials like ProPSMA, it becomes more and more clear that PSMA PET is the standardized imaging at many stages of prostate cancer. And I think there are challenges to that, that we have to capture in our future work, is how to really implement it in a way that our PSMA PET report has more than just staging, but is really a biomarker and gives us prognostic or predictive information on the one hand.

And on the other hand, to really make recommendations that are sound, that are evidence based, on how to use PSMA PET longitudinally within a study or within a clinical setup, how to report response in a way that the information is really prognostic or predictive. I think this is one of the major challenges for us to implement PSMA PETs to a deeper benefit within clinical studies, but also the clinical routine, more than just imaging, but really a biomarker of outcome.

Phillip Koo: I love that. Ken?

Ken Herrmann: So PSMA may has been a huge success story for the field of nuclear medicine. And as much as I like that you mentioned Essen, Essen only contributed a very, very small part. It's very important never forget that we owe a lot to the Heidelberg group, that we owe a lot to the Australians. ProPSMA, Wolfgang just mentioned, we owe a lot to actually UCLA and UCSF, who actually pushed forward the Kinetic MD, and we also actually owe a lot to industry, who finally took a compound and really brought it over the finish line and to approval.

What I personally really want to do is bringing all these different parts of the world and all these different innovative researchers together with a different classification and hopefully again establish common ground that we, in probably two or three years from now, we really agree on a way on how to report PSMA PET pretty much the same way in Australia, in the US, in Europe, and in Asia. And this is something where we also have to bring in clinicians. So for example, I think EANM, also the SNMI, ENM, ANZAC, there are players who need to be part of this. And this is what I hope to accomplish in next two or three years.

Phillip Koo: That's great. So PSMA is a biomarker and standardization, and I agree, standardization has so many benefits across the whole spectrum of cancer care. So appreciate that. Really appreciate the time that you guys took to speak with us today, and we look forward to talking to you again soon.

Wolfgang Fender: Thank you very much.

Ken Herrmann: Thank you.