Next Generation Imaging for Prostate Cancer

Neeraj Agarwal, MD: So I’ll just take a final takeaway from each one of you, Dr. Tward, Jonathan, any final takeaway for our audience here regarding PSMA imaging?

Jonathan D. Tward, MD, PhD: I think there will be very rapid adoption of PSMA imaging across the entire disease spectrum of prostate cancer. It appears to have a role from staging all the way on as was mentioned by Dr. Tagawa to possibly, as predictive markers, disease response assessments. It’s very exciting to have this tool in our arsenal, and I think we’ll be able to make much more thoughtful treatment decisions as a result.

Dr. Agarwal: Thank you. Dr. Tagawa?

Scott T. Tagawa, MD, MS, FACP: So on a practical basis, as you already mentioned, there’s a number of different agents available, and more coming. What they all have in common is they’re more sensitive and specific from anything else, and the differences between them, I think, are small. So whatever’s available, that’s fine. I don’t think a patient needs to travel a lot to get one versus the other, at least at the beginning, they’re all better than anything else. And costs might actually dictate what some will have available, but at least having some available, I don’t think an individual patient or doctor needs to quibble about the other ones. A couple of small things… Actually a study that Jeremie published, the reader interpretations of those issues in terms of normal distribution, that’s not prostate cancer, that they’ll have to learn, but the signal of [inaudible 00:01:43] is so much better than, say fluciclovine, so it’s just going to be easier, I think for the nuclear medicine, or radiologist to interpret PSMA Pet compared to say fluciclovine.

Dr. Tagawa: And then clinically, two situations, or three situations that I just want to point out quickly. So one is they’ll come for a recurrent disease, following surgery, PSMA PET negative, that’s actually probably the best scenario, still can get salvage radiation. So, something to pull out there. The medical oncology setting, [inaudible 00:02:15]. Someone that’s going to get treatment for tumor directed treatment for all metastatic disease. In my mind, use the most sensitive agent. We know from the Oriole study of those that didn’t treat all the lesions, it was 44% were missed, if you look at the PSMA PET. They did worse, so use a sensitive agent prior to MET directed therapy. In the setting of metastatic disease, that’s only found on PSMA PET. Because we don’t know the true prognostic value in that setting, I’m personally going back and getting some bone scans, so I will have an idea about the volume per chart, et cetera, to get an idea of what drugs, how many drugs am I going to use with that individual patient.

Dr. Agarwal: That’s perfect. That’s what we were looking for, exact recommendations on, or your opinion on how to use PET scans in different situations we are seeing in the clinic. Different types of clinical conditions, in patients with prostate cancer. Dr. Calais, any final takeaways on PSMA PET imaging in prostate cancer?

Jeremie Calais, MD MSC: Yes, I think in continuity with what Scott just said, I think now we have access to these new techniques, the pro and cons, the weaknesses of the technique are start to be known as well, so we know what we have in hands. Now the next question is how to use at best this new information. For example, if you have a negative scan, like Dr. Tagawa was said, it doesn’t mean you should not treat.

Dr. Calais: In fact, when you start to harvest the data of all these patient who got the scan in the past five years, you start to have natural data of outcome, a couple of years after the scan, and you start to have this [inaudible 00:04:17], and you see how they’re doing. And of course, if you have a negative scan, you do better than if you have a positive scan, if you are treated. So it’s maybe a way to select patients. You have a negative scan, then you would benefit from the treatments. Things like this, I think in the next years, five, ten years even, depending on which stage we’re looking at, we will learn how to use at best the PSMA PET staging information for different treatment algorithms. And this, you can apply this for any stage. And I think that’s now where we are now, and that’s also very interesting to see where it will go.

Dr. Agarwal: Fantastic. Well, thank you very much to all the colleagues, Dr. Tagawa, Dr. Tward and Dr. Calais for sharing your views on how we are going to be using PSMA scan or PSMA PET-based scan for diagnosis and management of our patients with prostate cancer.