Coincidentally, I had a conversation with a very knowledgeable man about
why JH, which has such excellent surgery and oncology departments, is so weak in radiation oncology. He attributes it to Walsh's bias."What competent RO would work there?" he said.
Actually, what he told you isn't technically wrong -- it's just "truthy." The reason the ED rates for BT and EBRT are about
the same as for surgery is because radiation guys have traditionally been much older. You can easily see the effect in the first table at the following link:Half of long-term erectile function (EF) loss after brachytherapy (BT) is due to aging
As you can see, in every age category, ED rates after surgery are worse than EBRT or BT. But the average is roughly the same because of the effect of age.
That's from the biggest study I know of. It looked at potency 2 or more years after treatment. It did not include HDR-BT or SBRT or combo therapy.