I recommend considering these inputs. They help to explain potential next steps, when, and why. At your level of PSA, the challenge is knowing where to radiate.
"What to ask when PSA is rising after the initial treatment:"
PCF - https://www.pcf.org/about-prostate-cancer/diagnosis-staging-prostate-cancer/psa-rising/what-to-ask-when-your-psa-is-rising-after-initial-treatment/
"Rising PSA after initial treatment. PCRI" - https://www.youtube.com/watch