MANAGING BIOCHEMICAL FAILURE AFTER RADIATION THERAPY — The Importance of Considering Both PSA and PSA Doubling Time

[zeitgeistxx]

Reposted from the Inspire PC site. What do you think?

grandroundsinurology.com/pc...

[Justfor_]

It is two to three years now that whenever I saw a post asserting that at a low PSA level PSMA PET scan doesn't stand a chance of detecting any lesions, I repeatedly stated that PSADT is equally if not more an important factor. After I became tired of posting the same over and over again, I posted the "Contradicting silly doctors' parrots". Present paper does it justice.

[treedown in reply to Justfor_]

It's not just the Drs. In my case my insurance company would not ok the PET/CT until I hit 2.0+nadir and had clear CT and bone scans. My Dr started pushing for the Pylarify first when I was at .5 I wanna say. That said my doubling time was under 2 months by then so pretty sure I was able to get the PET within a month of the original appointment. Everything else got done pretty quick after the insurance finally denied the PET the first time.

[Justfor_ in reply to treedown]

According to the nomogram appended in the above mentioned paper, your PSA of 0.5 contributes 29 points*, while the 2 months of PSADT 74 points, with the more collective points corellating to a higher detection probability. Consequenly, your PSADT at the time was 2.6 times more important than your PSA. When initially I was posting this, I wasn't making it out of my head. I had studied a Heidelberg paper providing the relevent probability coefficients. But, at that time PSMA was still in the "experimental" stage in the USA (before FDA approval) and docs were down playing its capabilities in order not to loose face against other countries in Europe, Australia, etc. And of course there are docs' parrots here that repeat, without thinking, any silly assertion docs may devise for any reason. One such example is: "there is NO PSADT for PSA less than 0.1" that later received a facelift in the form of: "PSADT for less than 0.1 is not validated". Unlimited silliness IMO.

(*) PSA of 2.0 contributes 52 points only

[treedown]

Yeah I had 3 consecutive rises by the time I hit .5 which was the previous point of BCR I believe. The desire to have 1 definition to fit all will always be the driving force I suspect. I don't feel it was too far off though in my case but I was keeping an eye on it myself and others should do so as well. No doubt PET/CT has changed the game in a very short ti.e, withing my dx, and the existing bureaucracy will take time and proof to catch up.

[j-o-h-n]

Anyone got a cracker?

Good Luck, Good Health and Good Humor.

j-o-h-n Saturday 05/13/2023 6:17 PM DST

[RMontana]

Yes, this was a good post that I had put up as well...here are my notes on the same podcast.

healthunlocked.com/active-s...

Also, not mentioned in the above podcast is that you cant use PSA values if TET is moving...you need stable TET levels or else the PSA value is not useful to calculate PSADT...check out Min 15:45 in this podcast.

healthunlocked.com/active-s...

Hope this helps...Rick