I just finished ~50Gy salvage radiation to my pelvic lymph nodes and spot radiation to 3 metastatic pelvic lymph nodes. The prostate bed was clear on scans and I got about
70Gy to that area 8 years ago after surgery. I am on Eligard + Xtandi until Jan 1, 2022 then I am off those and getting regular blood tests to see what happens. If nothing else I have kicked the can further down the road. My RO says he always has at least 1 guy in my situation in for treatment and indicates 'significant' success in stopping the PCa progression.
If it didn't work, then I am up for whack-a-mole as the mets show up. The question appears to be whether my immune system can be arsed to produce more CD8+ 'killer' T cells when presented with blood-borne pieces of dead cancer cell proteins.
As always, thanks for the links, Djin.