Hi Claire,
Hormone therapy (injections ) can be vey successful in bringing down the psa and holding the cancer at bay. My OH was diagnosed at 13000 with advanced disease and had dropped to 15, we have had a recent rise but he is doing very well 16mths on.
Have you applied for the tool kit on this site, it can be very helpful in explaining all of the different treatments. You can download it or have it posted to you.
It is quite normal for men with advanced disease not to have the prostate removed with surgery.
I am glad that you have found this site there are many people on here that will offer advice and support, so although it sounds weird to say welcome and keep posting. Let us know the outcome of your Dad's scans. Will keep fingers crossed for him.
BFN
Julie X