Combine the ground turkey breast, bread crumbs, chopped onion, parsley, Worcestershire sauce and hot sauce in a large bowl. Mix well. Divide turkey mixture into 4 equal portions and form into patties.
Prepare a hot fire in a charcoal grill or heat a gas grill or broiler. Away from the heat source, lightly coat the grill rack or broiler pan with cooking spray. Position the cooking rack 4 to 6 inches from the heat source.
Grill burgers until browned on both sides and heated through, about 7 minutes a side. Serve each burger on a bun topped with 1 tomato slice, 1 onion slice, 1/2 lettuce leaf and a dollop of fat-free mayonnaise.