PSA, MRI, Biopsy why doesn't PSMA Pet Scan

@dribbles
Doctors at the conferences I’ve attended to have said that the choline PET scan is not worth doing. Mayo is the only one that uses this scan, After all the years they’ve been using it, you would think they would at least have it at your places, but they don’t because it is not as effective as a PSMA pet scan.

Here is a slide From one of the conferences that shows the different PET scan results. The choline scan does not show the spots in the spine and over does the spots in the pelvic area When compared to a PSMA pet scan.

@jeffmarc
Thanks Jeff. I had the PSMA scan this am at Mayo. I was told they use the Choline Pet if nothing shows with PSMA in case the cancer does not emit PSMA.
I got my results back and everything is contained , single tumor in the prostate with no spread anywhere. My tumor is 4+4=8 . I meet with the surgeon in one week and Radiation in 18 days.
My prostate is enlarged and at 84 ml. Wondering if that would need shrinkage before radiation. I would appreciate any thoughts or ideas for questions. I really appreciate everyone on this site, it's very comforting to have this resource.

@dribbles Sometimes one is put on hormone therapy before radiation.
I was 2 years + ago. See my profile for my condition.

How dangerous is having repeat Pet & CT scans? I see the risk is generally considered low and outweighed by the diagnostic benefits for serious conditions like cancer. Is it true a CT scan alone is equal to 500 regular xrays? Shouldn't one limit how many Pet & CT scans are done, "if possible" ?Especially if they are not 100% effective in diagnostic results.

@dribbles
Frequently they do ADT before Radiation to try to reduce the size of the tumors and also the prostate. Two months Before I had Salvage radiation they gave me ADT. That was when my PSA hit .2 3 1/2 years after surgery.

They usually prefer to do that, For a Gleason eight would be pretty normal.

Funny thing is I never noticed the six month shot doing anything to me. When I went on the proud a few years later, I immediately got terrible hot flashes, but never had them when they gave me that shot before radiation.

The radiation should give you a good chance of remission since the cancer is isolated.

Anywhere else, but Mayo they give you an FDG pet scan if you have no PSMA being produced.

@dribbles Yes, Choline C-11 was one of the 3 PET scans used prior to the use of PSMA. (The other 2 were the Axumin and the F18-FDG PET scans.)

No one makes the case that the Choline C-11 or the Axumin or F18-FDG PET scans are even on par with PSMA PET scans..,,,unless the prostate cancers are PSMA-negative (as you indicated), in which case they fall back to one of those 3 pre-PSMA PET scans; Mayo is the only one that uses Choline C-11.

Since your prostate cancer was PSMA avid, they would’ve assigned a SUVMax score to it (indicating its aggressiveness). What was the SUVMax score they assigned to it?

With a Gleason 8, hormone therapy is recommended in the NCCN guidelines. (See attached NCCN Guidelines for high-risk prostate cancer.). The hormone therapy will shrink the prostate.

@brianjarvis
Thanks Brian, 8.9 score

@dribbles (You might already know all this……)

“SUV” stands for “standard uptake value” and is a measure of radiotracer uptake that indicates how high grade the cancer is. The higher the SUVmax, the more advanced the cancer.

The PSMA PET scan report should also reference the SUVmax scores of your:
> lacrimal (tear) or parotid (salivary) glands
> liver (hepatic)
> blood

As it turns out, PSMA (prostate specific membrane antigen) is not really “prostate specific.” There are other organs, tissues, and fluids that naturally express PSMA (without being cancerous) and will show up as physiologic tracer uptake on a PSMA PET scan - particularly in the lacrimal (tear) and parotid (salivary) glands, blood, liver, spleen, pancreas, ganglia, and more, as well as the kidneys, ureters and the bladder (as the body tries to quickly excrete the radioligand that was injected).

So, they use for comparison the PSMA SUVmax values of your blood (as the lowest level), liver (as the medium level), and parotid or lacrimal glands (as the highest level) of SUVmax expression.

If a suspicious area (lesion) is expressing PSMA, and it has:
> a PSMA SUV score less than blood, then it’s not likely cancer, but instead just normal, background PSMA cellular expression;

> a PSMA SUV score greater than blood, but lower than liver, then it’s likely low-grade prostate cancer;

> a PSMA SUV score greater than liver, but lower than the lacrimal/parotid glands, then it’s likely moderate-grade prostate cancer;

> a PSMA SUV score greater than the parotid/lacrimal glands, then it’s likely high-grade prostate cancer;

Where does your 8.9 SUVmax fall on that blood-liver-parotid(or lacrimal) SUVmax range?

As always, discuss all this with your doctor.

Thanks again, those scores were not in the report unless there is something
in the 1900 photos

They should be explicitly stated in the PET scan report. It could’ve been either overlooked or omitted. Often they’ll tell you only what they think you need to know rather than all that you’d want to know.

Without anything to compare to, there’s no way to know what “8.9” means. (Sort of like them telling you your PSA, or PIRADS, or Gleason, but not telling you what the ranges were. It would just be a number with no meaning.)

You should ask them: SUVmax scores for your blood, liver, and parotid (or salivary) glands.