Wolves seem to be having something of a moment. In January there was ''Clash: Encounters of Bears and Wolves'' on PBS's ''Nature,'' which looked at how the reintroduction of wolves into Yellowstone National Park has given the grizzlies there competition. Last month came the movie ''The Wolfman,'' with Benicio Del Toro as the man-beast. And on Sunday the Smithsonian Channel offers ''Running With Wolves,'' a film about Gudrun Pflueger, who has been researching wolves in British Columbia and Alberta, Canada, for years. But this isn't really a nature documentary. It's a cancer-survivor documentary. Ms. Pflueger is recovering from a brain tumor, and the program is, at heart, about her efforts to try to do the rigorous wilderness observations she once did. [ABSTRACT FROM PUBLISHER]