PCa found in GA-68 can no longer be found?!

What should I do when earlier PSMA scan finds cancer but it's gone (?) before we can radiate it? Background follows:
• PSA increased this Spring from undetectable to 0.90 (radical prostatectomy, salvage radiation and hormone therapy done in 2014-2015 after gleason 9).
• Gallium 68 scan in July found one prostate cancer node in my stomach area.
• Hormone therapy initiated in September (Firmagon/Lupron and Xtandi).
• Plan was to do cyberknife radiation of single prostate cancer node after "weakening it" through a couple months of hormone therapy.
• Now that the time for Cyberknife is here, doctor can't find the prostate cancer node (using PET CT, MRI and Axumin scans) as part of the planning process for the Cyberknife radiation.

Should I just be happy that the recent scans can't find any prostate cancer? Or are my recent scans just not picking up the cancer and I should do another Gallium-68 PSMA scan sooner or later?

I think your hormone therapy has shrunken the node or reduced the level of cancer which then makes it harder to spot. Axumin generally requires PSA greater than 1 or maybe even greater than 2, so it is not surprising your cancerous node cannot be located. Just my thoughts.

Every scan of every type, including the latest and greatest, has a size below which it cannot detect.

If treatment shrinks the abnormality, it can "disappear" from subsequent imaging.

Whether or not the abnormality is completely eradicated is unknown.

yup, that's a good plan.

Get 'er done.

Andrew