Unfortunately, there are really no known treatments once the case has gotten to this point. In some cases, people look for clinical trials that might match their situation.

Instead of having docetaxel You might ask to have cabazitaxel with the carboplatin. It is supposed to be a little bit easier with the side effects then docetaxel.

Xofigo Which was recommended by @brianjarvis Does work for people that have only bone mets, If there are any tissue, mets then you normally want to go the chemo direction.

Definitely talk to your doctor about these options.