Colwick Chris, could you sit down with the oncologist to talk about alternatives? The PSA progression is fairly slow; dad's consultant put his stats into a nomogram and calculated that if he did nothing it would kill him in about 20 years so he decided not to have salvage RT. You could perhaps go onto intermittent HT instead, along the lines of TopGun's strategy ... HT, knock it back, have a break, HT, knock it back, have a break? Plus I would want to know from the consultant "if I had already had salvage RT and it was rising again, at what point would you introduce permanent HT?" we know that this varies from specialist to specialist - Bri's consultant would wait until the PSA was 20 while others here report that it would be 5 or 10.
With your stricture problems, I would be reluctant for John to have RT - I would want him to have the best quality of life possible for as long as possible but might be tempted to play a bit of Russian roulette with hormone control instead?