My husband has been treated with Cyberknife radiation as part of the Pace trial at The Royal Marsden (Fulham Road.)
He was initially diagnosed with Gleason 3+4, T2C, PSA around the 4.5 to 5.00 mark.
Cyberknife radiation is carried out over five days and if you are low to intermediate risk will not entail any hormone therapy.
Since the Cyberknife in August 2018 his PSA has gradually decreased and is now at 0.27.
The only side effect he had was bowel urgency which was more of a feeling than an event. This has now abated.
Why don't you ask your doctor to refer you to the Marsden to at least talk about the Pace trials. There is no real urgency with your current grading so it's worth looking at other options.
From the information you've given, I believe that you would qualify for the Pace trial (if you've commenced any hormone therapy in the interim, this would preclude you.)