Don't get too worried about the other scans results yet. They are if nothing else very thorough in checking everything and getting the full picture.
The bone scan may not show cancer at all. It is to assess your bone strength and density see what arthritis areas they need to be aware of. This test is a setting test as a comparison for later on down the track when you are into hormone therapy as some of those drugs can be hard on your bones depending on your age.
The CT scan for me picked up fibroids in my uterus and I was having all sorts of kittens about it especially when I was sent then for an ultrasound inside and out on it. As it turned out, they just want to keep an eye on it in months and years to come and it doesn't have anything to do with breast cancer just at the present time so that's some good news.
They take into consideration your quality of life now and your expected quality of life after full treatment and your age. Some treatments are a bit rough for the really elderly but they still have treatments available for them which will not make them so sick so there is something for most everyone.
So glad my merry-go-round of tests is over now. It was full on at the start and I didn't know if I was Arthur or Martha lol.