A radiation oncologist in my case, in consultation with a medical oncologist, both at the Cancer Centre.

My memory's a bit hazy because I was in critical care recovering from 10+ hours of emergency spinal surgery with paralysis and a range of serious post-op complications (including an inability to eat), but I suspect they didn't want to wait two weeks or to introduce another drug— they needed to get my T down immediately, and in their experience, Firmagon was the best bet in my specific case. I suspect they were right: in the event, it reduced my PSA dramatically in a few weeks (from 67 at diagnosis), and brought it to undetectable in a couple of months.

And after that, with Firmagon+Apalutamide controlling my cancer so well, it wouldn't have made sense to risk switching until Orgovyx — another GnRH receptor antagonist, like Firmagon — became available here.

In any case, the outcome has been good. I just passed my 3rd anniversary yesterday, with no detectable recurrence.