Preheat oven to 350°.
Place bread in a food processor; pulse 5 times or until coarse crumbs measure 1/2 cup. Place crumbs on a baking sheet. Bake at 350° for 7 minutes or until golden. Set aside.
Cook pasta according to package directions, omitting salt and fat. Drain, reserving 1/2 cup pasta water.
Heat oil in a large Dutch oven over medium-high heat. Add radicchio, red pepper, and garlic; sauté 1 minute. Add spinach, olives, and oregano; toss 2 minutes or until spinach wilts. Add pasta and reserved pasta water; cook 1 minute. Remove from heat; stir in cheese, salt, and black pepper. Sprinkle each serving with 2 tablespoons breadcrumbs. Serve with lemon wedges.