I had radical robotic prostatectomy in Aug 2018. All pathology reports were great; however my psa did not go to 0 and gradually increased over the next year. Numerous tests, MRI, and a biopsy of a small lump in the prostate bed were all negative. I went to the Mayo Clinic in Aug 2019 and had a special test with radioactive isotope. Mayo Clinic was sure that the small lump was prostate cancer. They recommended radiation and 2 years of hormone treatment. I ultimately had 1 yr of hormone treatment coupled with radiation. The hormone treatment takes away testosterone which is the fuel for prostate cancer. The radiation kills the cancer cells. I have some side effects from the hormone treatment and from the radiation - which are expected. Mine have been mostly minor, but everyone is different. My psa has been 0 for the past 6 months. Much info is available online, but use reliable online sources like John Hopkins, Mayo Clinic, etc. So do your research and talk to different Drs. And ask God to guide you. Wishing you the best.