Dave, that's interesting.
If you get the opportunity to ask when you go back, it would be interesting to hear if they are thinking of (or even heard of) using C11 Carbon Acetate PET scans in the future, which is supposed to be significantly better than PSMA, particularly at PSA levels < 2. I haven't seen it mentioned anywhere in the UK.
Given Carbon Acetate is more "prostate specific" than PSMA (it hooks onto a fatty acid in prostate cells), it would seem to me to be a better agent for carrying Lutetium 177, if they can be chemically combined, possibly avoiding the salivary gland issues. It might make the use of Actinium 255 more viable too (Actinium 255 is better than Lutetium 177 for killing prostate cells, but when carried by PSMA, it's also better at completely destroying salivary glands).