How in tarnation would they do that? To inject traffic into the network, the attacker would have to compromise the access network. The RADIUS attack is not going to accomplish that.
I mean, I know nothing about your network. If your network access servers are within a datacenter under your exclusive physical control, perhaps it's not an issue since it requires a man-in-the-middle position. Something like a neighborhood cabinet DSLAM could be open to abuse?