It has a bad crease in it, so I'm going to say replace.
I noticed in a thread that's in the 96-04 GT forum, titled "Mach 1 build" that the body shop that was working on that car just cut out the damaged section and welded in a new piece, leaving the rest of the quarter panel in place. Perhaps your car is a candidate for that type of repair.
Sorry that happened to you.
Was the truck badly damaged?
I love old F-series...