I think the original question was about launching Topaz from legacy versions of PS and LR, and I don't know the answer to that.
With the CC versions of PS and LRC, when you install Topaz apps, it also installs extensions (is that what they're called?) that allow you export a copy, open it in Topaz, work on it there, then return everything to Adobe when Topaz finishes. Very handy. It's pretty much the only way I work in Topaz.
But that's not the only way. You can, indeed, open Topaz and work on any image without getting Adobe involved at all. You'd have to do your exports and imports manually from/to Adobe, but you can just do the Topaz piece by itself. The import back into LR or PS is the most burdensome piece of that method. Whether that's too burdensome would be an individual opinion.