Tall Allen had much to say about
this. Seek him out elsewhere, or search this forum's archives. The general consensus after a lot of sturm and drang was that adding brachy generally improved cancer control, offset by an increased risk of side effects such as urinary strictures.
Vanderbilt's Cancer Center, back in 2013 when I was treated, also was not in favor of brachytherapy addition. They're a regional referral center for those suffering side effects from treatments elsewhere, hence quite aware of those outcomes. I pushed for brachy myself back then, and my RO made pretty much the same comments as the UW doc. My RO said that Vanderbilt does brachy, and if he thought it better for my case that he would do it; he didn't. He made the same argument, that the benefit doesn't justify the side effects.
Keep in mind, while "urinary stricture" sounds a little medical, a little sterile, living with that problem can be difficult indeed. But still, when making any treatment choice it's a personal decision whether to role those dice or not. If you pursue it, you can find a doctor or team of doctors to do what you want done.
This topic led to considerable disagreement on this forum, becoming a bit ugly. I wouldn't suggest we let that happen again.
55@Dx on 4/16/13. PSA 5.2, G9(5+4), PNI+, cT3a by MRI.
IGRT - 44 sessions (79.2 Gy, 50.4 Gy pelvic)
ADT2 - Lupron+Casodex (5/13-3/16)
8/13-5/16 <0.1 (ADT2)
5/16-3/17 recovering from ADT2
3/17-7/18 ~ 0.6 - 0.8 (no TX)
10/18 = 1.0, 12/18 = 0.9My Story