Hi Sandyg34,
Welcome to the board!
If you haven't done so already, I can thoroughly recommend downloading (or requesting) the "toolkit" on this site. This is a collection of fact sheets that give plenty of information about the disease itself, the various treatment options (there are more than two, and many flavours, both of prostate removal and radiotherapy), the probable side effects and how long they are likely to last.
You'll find that picking the 'right' treatment will depend on how far the cancer has advanced, the general heath of your father and the potential side effects he is willing to put up with post treatment.
You mention the oncologist saying the cancer has started to breakout of the prostate. This could just be a "bowing" of the capsule. Has your father had an MRI scan? Also do you know the results of his latest PSA test, both of which can point the way to choosing the "right treatment".
If you have any specific questions you'll find there are plenty of people on this site who will be able help, both commenting on treatment options, the side effects and aftercare.
Flexi