Just had Psma-pet scan... Confused

[GSDF]

My initial Axium pet scan nearly 2 years ago showed "innumerable" mets throughout musculoskeletal system, from head to knees... Understandably, my PSA at the time was 480. After 1 year on ADT and 8 months of Xtandi another Axium showed mets in calvarial region (skull), neck and clavicle no longer present... PSA plummeted down to current and holding at around 2.

My new oncologist at Kellogg Cancer Center sent me for psma-pet scan last week. Results reveal "Musculoskeletal: Innumerable radiotracer positive osseous lesions are present"

I don't see M. O. til Tuesday so I just wanted to present my question here for anyone who may know. How can I have so many mets that are obviously psma expressive, yet have such a low PSA reading?... I should add that other than ADT side effects, I remain totally asymptomatic.

[Tall_Allen]

They are probably smaller than the Axium metastases.

[GSDF in reply to Tall_Allen]

Thanks Tall...Oh I see....does this mean that an Axium at this same time would have detected less mets?

[Tall_Allen in reply to GSDF]

PSMA PET scans detect more metastases than Axium PET scans:

prostatecancer.news/2016/12...

[GSDF in reply to Tall_Allen]

Thank you brother... A most comprehensive link...🙂

[Gabby643 in reply to Tall_Allen]

thanks T A!

[cesces in reply to Tall_Allen]

Interesting. I was wondering what your analysis would be.

Any thoughts on why the low psa levels?

[Benkaymel in reply to cesces]

I've been on Xtandi for 9 months and although my PSA has dropped to 0.05, the mets have not reduced. In fact, some lymph nodes are increasing. I'm wondering if the cancer is changing due to the Xtandi to a type expressing low PSA?

[cesces in reply to Benkaymel]

That sounds logical to me.

You should get ta's opinion.