Hi Nig14,
Sorry that you find yourself in this situation. There are people on this site much better informed than I am, and hopefully some of them will see your post and offer their views.
I was diagnosed in May of 2022 and opted for Radical Prostatectomy, because I hoped that my prostate cancer would be completely excised and I would recover continence and erectile functioning in due course. I thought that radiotherapy was likely to lead to longer-term erectile problems which would not improve over time. And I was only offered radiotherapy with Hormone Therapy, which I definitely did not want. (They didn't offer me Brachytherapy). So, in short, I took what I hoped would be short-term pain for longer-term gain.
So far, ( 9 months later) I'm still incontinent and have no erectile functioning (apart from that provided by a vacuum pump or Alprostadil injections). I'm still hopeful that it might yet improve. Apparently, it can take up to 2 years to recover sexual functioning. The incontinence is slowly improving with lots of lower abdominal ('Kegel') exercises.
In my case, after they had removed the prostate, they were able to tell me that it had pushed through the prostate capsule, so I was upgraded from T2 to T3a. I have since been informed that there is a likelihood of recurrence in the 'prostate bed' at some future point, so even with a prostatectomy, there is no guarantee that they will be able to remove 'all' of the cancer cells, as you might be expecting. (However, my PSA is currently undetectable, so further treatment is not on the horizon yet).
The Kidney Transplant that you are facing seems more pressing, as any possible prostate cancer recurrence (if it happens at all) may be many years away. If the Kidney Specialist is happy for you to have any of the treatments offered, then in a sense, it's a more difficult decision for you because you're not being steered towards any particular treatment. Read as much as you can about all of the treatments on offer, but in the end it may come down to 'which of the side effects do I wish to avoid the most'?
Good luck to you.
JedSee.