Sounds like you probably are going to be getting salvage radiation to treat the area that still has cancerous tissue. This is frequently done.

They may want to put you on ADT to prevent a recurrence, And possibly even a second drug abiraterone or one of the lutamides.

Those are pretty common things to be done, especially if you have a Gleason nine.

This is very treatable, Make sure you’re working with a center of excellence or a Genito urinary Oncologist for your future needs. That will give you the best chance of a long overall survival.