1 Department of Surgery, Division of Urology, The Surgical Oncology Program at Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, Colorado.
2 Department of Pediatrics, Section of Pediatric Oncology, University of Colorado School of Medicine, Aurora, Colorado.
3 Department of Urology, University of Kentucky College of Medicine, Lexington, Kentucky.
4 Department of Pediatrics, University of Kentucky College of Medicine, Lexington, Kentucky.