PSMA PET Scans...some interesting info

@brianjarvis Thank you, Brian, for the link to Dr Kwon’s presentation. I like his speaking style so much more than many of the other experts.
But here’s the one thing I don’t get - and probably it’s MY fault for not getting it - but he says we always want to treat earlier rather than later; great, I agree…
…but then he makes that statement about NOT treating anything until you can see it, since only about 30% of men have recurrence in the prostate bed…Huh?? He just said to treat it early, ideally < 0.2…
I went back and reviewed my own PSMA: clear with no sign of activity ANYWHERE - not even in the ‘focal bed’, yet my PSA of O.18 prompted treatment.
Don’t get me wrong, my PSA was rising - but slowly and inconsistently over a period of about 18 months; NOT on a pace where PSA velocity was even an issue. It was more like: only PCa would cause a consistent rise in PSA over time, not ‘normal’ tissue left behind from surgery…who really knows, right?
Anyway, I had 25 radiation treatments to the bed+ pelvic nodes and 6 months ADT and am now undetectable.
But isn’t Dr Kwon saying that I should not have done anything? I should have waited for bright lights on my PET since nothing was visible? Wouldn’t that be too late rather than too early IF I was one of those men in the 30% whose recurrence was still confined to the prostate bed?
@jeffmarc has mentioned Dr Kwon’s preference for SBRT on visible lesions (over SRT on invisible ones) many times - and Dr Kwon illustrates this treatment with a few actual cases he’s successfully treated using this approach.
But what I think would be more telling, is how many cases slipped thru the cracks and became widely metastatic during the interval where lesions were invisible and then when they lit up like a Christmas Tree…? Nobody bats 1,000 pct- not even Dr Kwon and unless I am interpreting what he is saying incorrectly, his approach sounds like a bit of Russian roulette to me…
I have no regrets whatsoever that I opted for SRT - even in light of a negative PSMA. My PSA could still be rising to levels portending an unfavorable outcome (>0.7) and my PSMA could STILL be negative…How can you wait?? Best,
Phil

@heavyphil I guess Dr Kwon's point — which clearly not every colleague agrees with — is to refrain from hitting the fire button until you have something to aim at. But once you know where the target is, react fast.

@brianjarvis Thank you, Brian, for the link to Dr Kwon’s presentation. I like his speaking style so much more than many of the other experts.
But here’s the one thing I don’t get - and probably it’s MY fault for not getting it - but he says we always want to treat earlier rather than later; great, I agree…
…but then he makes that statement about NOT treating anything until you can see it, since only about 30% of men have recurrence in the prostate bed…Huh?? He just said to treat it early, ideally < 0.2…
I went back and reviewed my own PSMA: clear with no sign of activity ANYWHERE - not even in the ‘focal bed’, yet my PSA of O.18 prompted treatment.
Don’t get me wrong, my PSA was rising - but slowly and inconsistently over a period of about 18 months; NOT on a pace where PSA velocity was even an issue. It was more like: only PCa would cause a consistent rise in PSA over time, not ‘normal’ tissue left behind from surgery…who really knows, right?
Anyway, I had 25 radiation treatments to the bed+ pelvic nodes and 6 months ADT and am now undetectable.
But isn’t Dr Kwon saying that I should not have done anything? I should have waited for bright lights on my PET since nothing was visible? Wouldn’t that be too late rather than too early IF I was one of those men in the 30% whose recurrence was still confined to the prostate bed?
@jeffmarc has mentioned Dr Kwon’s preference for SBRT on visible lesions (over SRT on invisible ones) many times - and Dr Kwon illustrates this treatment with a few actual cases he’s successfully treated using this approach.
But what I think would be more telling, is how many cases slipped thru the cracks and became widely metastatic during the interval where lesions were invisible and then when they lit up like a Christmas Tree…? Nobody bats 1,000 pct- not even Dr Kwon and unless I am interpreting what he is saying incorrectly, his approach sounds like a bit of Russian roulette to me…
I have no regrets whatsoever that I opted for SRT - even in light of a negative PSMA. My PSA could still be rising to levels portending an unfavorable outcome (>0.7) and my PSMA could STILL be negative…How can you wait?? Best,
Phil

@northoftheborder Well, North, I certainly had no target but it’s like the old saying: ‘where there’s smoke, there’s fire’
Phil

@heavyphil It's probably on a similar trajectory to PSA testing, following the Gartner hype curve. First they find a new diagnostic tool and get very excited. Then they over-apply it. Then a reaction kicks in and they stop using it as much as they should. Then finally they figure out how to fit it in with the rest of the ecosystem and make it genuinely useful.

PSA testing fell into the Trough of Disillusionment 10-15 years ago, because doctors were making too aggressive treatment choices (especially for older patients) based on only mildly-elevated PSA readings. As a result, health authorities stopped recommending routine PSA screening in most countries, and the number of de-novo *advanced* prostate cancer cases shot up through the roof (because they starting missing the more-serious cases). Now they're cautiously moving back towards routine screening, but without an overreaction to a mildly-elevated PSA, with new options like active surveillance.

I'd say that PSMA-PET scans are currently teetering at the top of the Peak of Inflated Expectations, and there will be a strong reaction to over-treatment (like radiating every little spot that lights up "just in case"), but eventually it will find its place.

@northoftheborder my urologist explain it this way! ( in my words)
new innovated medicines ,technologies was like “finding a needle in a hay stack” Until a year or so ago ,they found the needle and the medical advancements are being introduce daily instead of every few years.
Great news for us in need of solutions for survival

@heavyphil In one of Dr. Kwon’s other videos, he says “If you can find it, you can fight it!” That’s probably key in “treating it earlier rather than later.”

I typically see references to doctors waiting until PSA hits 0.4 ng/mL before following up with a PSMA PET scan; at least then there’s a 50/50 chance of seeing a lesion. The risk with going in early (& blindly) is that radiation damages healthy tissue; the risk with going in late is that the cancer might be aggressive (which is why frequent PSA testing would be necessary if waiting.)

Earlier is better, but a false negative with a very expensive test is problematic. (That may also be why Mayo Clinic is said to follow a negative PSMA PET scan with a Choline C11 PET scan, which isn’t dependent on PSMA.)

I suspect that there wouldn’t be much difference in “lighting up like a Christmas tree” when comparing PSAs of 0.2 ng/ml to one of 0.4 ng/ml.

(If I should have a recurrence, the technical definition of biochemical recurrence following initial radiation - a PSA rise of 2.0 ng/mL above nadir (called the Phoenix Criteria) - was established in 2005 (20 years ago!) when modern imaging techniques (like PSMA-PET scans) that can detect recurrence at lower PSA levels were not available. It’s now known that BCR can occur following initial radiation well before that “2 points over nadir” threshold is reached. The Phoenix Criteria served its purpose well - to differentiate true cancer recurrence from PSA fluctuations in order to prevent overtreatment, but is now likely outdated, with today’s earlier and more effective diagnostic techniques.)

@heavyphil Very true, and I even if I were a doctor, I wouldn't try to second-guess your medical team. I think the question Dr Kwon is asking is "where's the fire?"

@pcfightclub Exactly. 5 years ago, before PSMA-PET, they couldn't find the needle in the haystack. Now they find the needle, but also lots of straw slivers that just look like needles.

The next step is learning the tell the needles and the needle-shaped straw slivers apart.

@northoftheborder Haha! If only life was that cut and dried, right? But we’ve all heard stories of firemen causing more damage - axing open walls and ceilings for a suspected fire that wasn’t really there. SRT probably has some of that, I’m sure…Best
Phil