I'm no doc, but I did stay at a ....no I didn't
I say this because I would suggest that you ensure that it's the same exact test read the same exact way as the one you had for PC... Your doc(s) should be able to tell you that.

But with that in mind.

Ultimately what it seems to mean to me is that there is slightly less uptake of the marker / dye / radioactive tracer in the areas that were noticed before which would mean slightly less metabolic activity...or slightly less cancer cells or cancer cell activity.

I would take the "mildly decreased" to mean that it isn't a large change, which is still good in two ways, the progression may have been stopped for now and of course, it's a little less than last time.

Best of Luck to you!