1. From the Department of Pediatrics, Division of Pediatric Surgery, University of Padova; Departments of Pediatric Hematology-Oncology and Surgery, and Service of Diagnostic Radiology, Giannina Gaslini Children's Hospital, Genova, Italy; Department of Pediatric Oncology, and Services of Statistics and Diagnostic Imaging, Institut Curie, and Department of Pediatric Surgery, Armand Trousseau Children's Hospital, Paris, France; Department of Surgery, The National Hospital, Rikshospitalet, Oslo, Norway;...