Prostrate Cancer is now in my Bladder neck

After 30 months of office visits and visit to outpatient surgery center to investigate further all my tests came up Benign. But my PSA continued to climb to 17.+ without explanation. Pushing and insisting that my doctor find resolve, he finally scheduled MRI at UCLA. They located cancer in area that was not reachable thru any previous testing. At 62 years old I agreed to have my prostrate removed this past January 2019.
After the surgery I was told it was unusually aggressive and had already grown out of my prostrate and into the neck of my bladder. There was 3 small pieces of cancer they could not or did not remove. They have checked my PSA at 6 weeks after surgery, March and June. I was told last week my PSA had increased, I'm having PSA test done every 3 weeks to confirm. If confirmed my Doctor has recommended to have Radiation treatments.

I'm currently scheduling appointment to have second opinion, most people I speak have had their prostrate removed without any further trouble or have horror story's of what happened to their dad, brother or friend. I'm just looking for opinions on steps and possible tests to request. My doctor is actually the department head at large hospital, I do not doubt his credentials but know second opinions are the smart steps. Your thoughts.