Hi Joe, yes, you can ask anything.
I went in originally, naively saying I wanted it taken out. They recorded that as my preference (I didn't know that until much later, when I got a copy of my medical records). Each time I saw a consultant (I ended up with many appointments over a long diagnosis), they always updated me on prostatectomy, but also told me about radiotherapy. I asked about nerve sparing, and was told unlikely given it was quite widespread in the prostate. They also thought there was a significant chance I'd need radiotherapy afterwards, incurring both sets of side effects, so why not just have radiotherapy in the first place? I had actually already decided on radiotherapy, but I didn't think to say I'd changed my preference.
When I was passed over to oncology, we talked about HDR Boost, and joining the PIVITOLboost trial. My oncologist thought, as a high risk patient, it was important I did one particular arm of the trial which is not something you get to choose on the trial (it's a random choice), so they treated me according to that trial arm (which was one of their standard protocols anyway). The specific part I went for was including pelvic lymph nodes in the external beam treatment at a reduced dose, supposedly to mop up any micromets (mets too small to show up on scans), given that's where they expected the cancer to go next in my case. They said it was rare to get any long term side effects from doing this. Also, it was thought erectile dysfunction might be less with this route than with doing it all as external beam (and that's already less than with prostatectomy). I did make it quite clear that sexual function was quite important to me, and I've been lucky in that respect - everything still works fine, and rather unusually, it mostly did all through the treatment too except for loss of libido and more difficult to orgasm.
I do actually have a long term side effect, rectal bleeding from the radiotherapy. In my case it's minor, painless, and causes no incontinence, so no impact on quality of life. I'd still make the same choice again.