If I may add a different opinion on item 2 above:
2. No prostate radiation, not even seeds, as the prostate is sitting right on the pouch. The risk of pouch irradiation and failure is too great a risk.
My husband has had two rounds of Radiation; first round of Stereotactic RT in 2016. Cancer came back in 2021. Second round (called salvage RT) was done through Brachytherapy (Sept. 2022). Yes, the pouch sits immediately next to the prostate, but they use a SpaceOAR; it is hydrogel that prevents the pouch from receiving radiation. Our latest PSA showed a drop, so we are hopeful it worked. We also had a full exam by his gastro who assessed the j-pouch to be in great health 5 years after the first Radiation Treatment.