SANCTUARY,
My husbands PSA was never undectable following RP as you can see by his stats below.
His PSA was rising post RP (and the doubling time) as it is considered, so quickly that it was assumed his tumor had already escaped and is now in his spine, so we deceided not to do RT and just did HT so far sucessfully.
Wait for your next PSA test to determine if it will be undectable with HT.
Every man's journey is different so you can't compare to anyone else's journey, I am just sharing with you our case.
Good Luck,
BOOGEE