Everyone above has offered you excellent advice.
If I might make a suggestion, your father may well benefit from attending a meeting of the local UsToo Prostate Cancer Support Group
in your area. This is a totally volunteer organization.
Here he will have the opportunity to personally share experiences with other Prostate Cancer Survivors.
Should your father be interested, you can go to www.ustoo.org to find a chapter near you.
I have been attending meetings for the last 8 years and it has been a source of great comfort and information for me.
Hope this is helpful.
I wish your dad the best of luck.
Bob