I am sorry to see this, spaull. Not sure that I agree with Heenan that 2.2 is not to be concerned about - the PSA doubling time is worrying, which is why they have added the Bicalutimide. Hopefully, Neil will see a drop at the next test.
It may be that 2.2 is too low for a scan to be worthwhile though - wherever the remaining cells are, they would have to make a pretty significant tumour to show up. You could ask whether a choline PET scan is available in your area, or enquire whether Neil could get on the trial of a new tracer which is more sensitive than choline.