I had RT/HT treatment and used a saddle like the Selle model you mention for a period while I was having RT. I can certainly recommend it for comfort over distance. I've since returned to using my original Fizik Arione [with a groove] mainly because I'd ridden on it so much, it felt odd sitting on something else. As I understand it, it's more important for immediate post prostatectomy people to use a friendly saddle and not of huge significance to RT people.
Unfortunately for me I was recently knocked off my bike at speed by a hit and run driver ... cracked rib, cracked coccyx, lots of bruising and a couple of months recovery time, but I'm still alive when it could have been a whole lot worse. I think I might steer clear of the road in future. Traffic has grown massively in recent years and along with that, impatience and outright aggression.
Jules