How does avascular necrosis of the femoral head affect definitive radiation to the prostate?

I asked the question and have no long-term follow-up to draw on to answer it. For what it is worth, I will summarize below what I learned from discussion with one experienced orthopedic surgeon, plus some reading. If others have insight/comments/opinions, please share!

1. AVN is irreversible. Risk factors include steroid use and alcohol (also increased risk with several underlying conditions).
2. Nonsurgical management should be tried for patients with tolerable pain, but it is often unsuccessful.
3. My surgeon consultant says he has never heard that prostate radiation could cause AVN and does not believe it is a significant risk, given the low dose the hip receives with modern IMRT. This is consistent with what we know about osteonecrosis in head...

Don't forget brachy, no entrance dose through hips, and falloff occurs rapidly as the square of distance from the HDR source.