Dear BoeingBoy,
I am not a physician so I am unprepared to give you professional medical advice. I have plenty of hospital experience, however, having worked as specialized technician at Crawford Long Hospital, the teaching facility of Emory University in Atlanta, Georgia, U.S.A. The oncology wing housed a number of Delta pilots who had undergone a full prostatic resection (some via TURP, others via abdominal incision), so I don't believe your exposure background radiation would preclude further targeted radiotherapy, pre- or post-surgically. As an aside, one wonders if your vocational dose levels may have been contributory to CA's development.
Funny that you mentioned "John Wayne Walking" and the human perineum. Should you need a laugh, check out my post to Fliegenmong in the thread called "A Delicate One". It's in this Forum.
I know I share the hopes of many other PPRuNers: we wish you a complete and painless cure and recovery!
- Ed