Gleason nine is an aggressive cancer. While ADT may manage it for a while, it will not do it for long, The PSA will start to rise, even while on it.

Rather than just ADT, they will probably want to put you on ADT and an ARSI (Zytiga or a Lutamide like Enzalutamide etc.)

It is really essential to treat the prostate in order to stop the cancer from spreading again after treatment.

ADT does not kill the cancer in any way, it just stops it from growing and spreading for a while.

If you can’t do radiation then surgery works well. Your cancer will spread a lot if you don’t do something. If you want the best chance at a long life, you must do one or the other.