Phillip Koo: Welcome back to the 13th International Uro-Oncology Conference here in São Paulo, Brazil. We have with us today, Dr. Icaro Carvalho, who's a radiation oncologist at Albert Einstein, who's giving a couple lectures on the role of radiotherapy. One question I wanted to start with was, what are your thoughts on adjuvant or salvage radiotherapy in patients with prostate cancer, recurrent disease?

Icaro Carvalho: Yeah. Nice question. I think more and more, we are using salvage radiation because of the RAVES and RADICALS results. But what we see in practice is that many urologists, they don't send the patient to the radiation oncologist when the PSA gets to 0.2. That would be the better situation. So, there are sometimes that we need to use avant radiation like N-positive patients or advanced Gleason score. What happens here in Latin America is that sometimes the urologists wait to get a higher PSA, and we know that for salvage, that's not very good, because the lower the PSA, the better the patient's chances to get cured.

Phillip Koo: Now that Brazil's had access to PSMA PET for a while now.

Icaro Carvalho: Yes.

Phillip Koo: And the fact that it can detect recurrent disease much sooner, I imagine that's had a big impact on your practice. Can you talk a little bit about that?

Icaro Carvalho: Yes. We have PET PSMA since 2017, and there are some papers showing that in recurrence cases, prostate cancer recurrence cases, we can see the place where it recurred, and in about 8% of the times, we've got to change the radiation fields. So it impacts a lot of our practice

Phillip Koo: Locally advanced disease is another hot topic here in Brazil with regards to the role of radiotherapy. How does radiotherapy fit in that space, especially here in Latin America?

Icaro Carvalho: Yeah. I think we have more level one evidence for the use of radiation and hormone therapy for that patients. But most urologists here in Brazil prefer to perform prostatectomy. We don't know why, because we know that most of these patients will need radiation after that, and maybe we are adding just some toxicity and not a good result for the patient. I don't know what happens. Maybe it's because we have a lack of linear accelerators in Latin America. We had to have double the number of LINACs that we have now, so not everybody gets access to that. So I think maybe that's why most of them go to surgery.

Phillip Koo: Access is a major issue, and I think that does definitely influence practice patterns and referral patterns, so I could understand that. A question I have for you is, in your practice with access to PSMA PET readily, are you routinely getting a PSMA PET in patients with high-intermediate or high-risk disease or very high-risk disease?

Icaro Carvalho: Yes. We have some evidence that it's a good tool for staging the patients. So for high-risk patients especially, we always ask for PET PSMA instead of scintigraphy and other exams. It's only one exam, it's better for the patients. It's easier.

Phillip Koo: Yeah, I agree. And in the US, at least, one of the landmark papers that came out from the NCCN was they did not require conventional imaging prior to getting a PSMA PET, just cause we know the PSMA is so much better.

Icaro Carvalho: Yes.

Phillip Koo: So shifting back into the biochemical recurrence space. In radiation oncology, we talk a lot about the Phoenix criteria, the Phoenix definition of biochemical recurrence. What are your thoughts on that? I imagine our approach might need to be a little different now that we have more sensitive imaging.

Icaro Carvalho: don't know if the Phoenix definition is good for prostate cancer recurrence after prostatectomy. I think it's a very good tool for patients that were irradiated.

Phillip Koo: Sure.

Icaro Carvalho: So, every time, more and more, we ask for PET PSMA with lower levels of PSA, 0.2, 0.3. We know that the lower the PSA is, the lower is the sensitivity of the tool. But if we find something, it will change the way we treat that patient.

Phillip Koo: So in a patient who has a low PSA and you get a PSMA PET and it's negative.

Icaro Carvalho: Okay.

Phillip Koo: Do you still proceed with salvage, or do you wait until you see something positive?

Icaro Carvalho: I don't know why waiting, because we know that the lower the PSA when we offer radiation, the better are the results. So we don't know if we can find the place where it recurred with a higher PSA if the results will be equal to radiation with lower PSA. So, I always offer radiation.

Phillip Koo: Yeah, and I would agree. I think there's a paper out Australia which confirms salvage locally, even with a negative PSMA, that has improved outcomes. Great. Thank you very much for joining us. We appreciate your time and your information.

Icaro Carvalho: Thank you very much. Thank you.