Manager Sam Maydew says the 73-year-old actor and artist is being treated through a "special program" at the University of Southern California.

Asked about Hopper's prognosis, Maydew said, "We're hoping for the best."

Hopper was forced to cancel his appearance at an exhibition at the Australian Centre for the Moving Image in Melbourne called "Dennis Hopper and the New Hollywood," a collection of artwork and photography by the actor.

Hopper recently finished shooting the second season of TV's "Crash" and has several film projects in the works.