@Jade_NL has already answered correctly: there is no plugin support. But then again, most people will agree that the out-of-the-box denoise algorithm of RT and its negative conversion (available in the current development version) are pretty damn good. So the question here might be: do you really need the plugins?
I started using Topaz recently and find for my taste it does a much better job than Adobe Camera Raw, and with very minimal values on the sliders, usually I use zero sharpening and less than 3 on the Noise slider, often only 1! My main goal is to denoise the background of empty space without significantly impacting the subject. I went ahead and bought it and use it both from the standalone app and PS plugin.