Another option would be to have a sedative. You won't remember the procedure afterwards, and it doesn't come with all the additional baggage of a GA (theatre time, anethestist, etc), but you will need someone with you to take you home.
At the time I had my procedures, SpaceOAR was mainly inserted under GA. That's becoming less the case now, but there probably are places that would still do that. (I couldn't have SpaceOAR, but it was considered a couple of times.)
If is was just gold marker insertion, treatment can be done without that, but then you need a CT scan (or more strictly, a CBCT scan) at the start of each treatment, which takes 5 mins longer (increasing treatment cost), and the CBCT scans themselves slightly raise the X-ray dose to OaR (Organs at Risk - nearby organs which you are trying to avoid treating such as bladder and bowel).