Hello EL2016 and welcome to the site.
Nidge is right in suggesting you seek help via counselling while you are away from home or from the nurse on this site but hopefully a member will be along who has investigated the cyberknife technique and may be able to help you.
Prostate cancer treatments are evolving all the time with trials being undertaken on the best way of dealing with this disease so please don't despair.
You don't say whether you're male or female, not that it makes a difference to how you feel about your dad of course but it might help us to help you if we knew whether you were a young female or a young man.
We pride ourselves on being supportive of each other and helping where we can with advice so you don't have to feel that you are alone any longer because now that you've found us we can give you a shoulder to lean on. It might not seem much when you are feeling so desperate about your dad's future but talking about it all does help, so remember, here we are.
When you get the details of the next step for him, or you need any other answers please ask
Sandra