[1] Univ Amsterdam, Acad Med Ctr, Dept Pediat Surg, Emma Childrens Hosp AMC, NL-1105 AZ Amsterdam, Netherlands
[2] Netherlands Canc Inst AVL, Amsterdam, Netherlands
[3] Leeds Teaching Hosp Trust, Leeds, W Yorkshire, England
[4] St Georges Healthcare NHS Trust, London, England
[5] Univ Hosp Padua, Padua, Italy
[6] Hop Trousseau, F-75571 Paris, France
[7] Univ Tubingen, Childrens Hosp, Tubingen, Germany
[8] Univ Munich, Dr von Hauner Childrens Hosp, Munich, Germany
[9] Univ Homburg Saar, Homburg, Germany
[10] Inst Hematooncol Pediat, Lyon, France
[11] Great Ormond St Hosp Sick Children, London, England
[12] Inst Child Hlth, London, England
[13] Sophia Childrens Univ Hosp, Erasmus MC, Rotterdam, Netherlands
[14] Astrid Lindgren Childrens Hosp, Karolinska Inst, Childhood Canc Res Unit, Stockholm, Sweden
[15] Univ Amsterdam, Acad Med Ctr, Emma Childrens Hosp AMC, NL-1105 AZ Amsterdam, Netherlands
[16] Marciniak Hosp, Wroclaw, Poland
[17] Med Univ, Wroclaw, Poland