1. Cindy Kenis, Koen Milisen, Johan Flamaing, and Hans Wildiers, University Hospitals Leuven; Koen Milisen, Johan Flamaing, and Hans Wildiers, Katholieke Universiteit Leuven; Lore Decoster, Katrien Van Puyvelde, Jacques De Grève, and Godelieve Conings, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels; and Jean-Pierre Lobelle, Consultant in Statistics, Beernem, Belgium.