I had radioactive seeds implanted in late 2002. The doctor who performed the procedure had told me when I asked him about sexual function afterward, and he stated "I'd be about the same". Not quite.
I had a PSA of 8 at my yearly physical in 2002, and my doctor referred me for a biopsy. A week later, my PSA was back down to 4, and it usually ran in the high 3's. And I received that short film put out by the company that makes the radioactive seeds, where 4 or so of the most prominent doctors in America discuss seeding and make it sound as though it's just a "small inconvenience".
Take care of your health, but to do that seek a second and third opinion if you're fortunate enough to not have an aggressive cancer, and talk with other men who have gone through different treatments. I seriously think I would have played the waiting game if I had to do again.
I guess I'm sick or something, and my heart does go out to all you men with really serious and possibly life-ending cancers, but I just loved women and sex, and that's one of the few things in life that I was really good at, so losing that ability has really made things a lot more difficult, and I have tried everything I know to try and do, and I am grateful for life itself and the ability to do so many other things, but still, it's like a huge part of me is missing. I think some men will understand this, and others will be really critical, and to each his own, I respect anyone else opinion.