[1] Great Ormond St Hosp Sick Children, Dept Paediat Oncol, London, England
[2] Hosp Univ Nino Jesus, Dept Paediat Haematol & Oncol, Madrid, Spain
[3] Catholic Univ Louvain, Clin Univ St Luc, Brussels, Belgium
[4] Ctr Oscar Lambret, Pediat & AYA Oncol Unit, Lille, France
[5] Royal Aberdeen Childrens Hosp, Dept Paediat Oncol, Aberdeen, Scotland
[6] Ist Giannina Gaslini, Oncol Unit, Genoa, Italy
[7] Univ Hosp Essen, Pediat Hematol Oncol, Pediat 3, Essen, Germany
[8] Hosp Univ La Paz, Pediat Hematooncol Dept, Madrid, Spain
[9] Jagiellonian Univ Med Coll, Inst Pediat, Pediat Oncol Hematol Dept, Krakow, Poland
[10] Princess Maxima Ctr Pediat Oncol, Dept Solid Tumors, Heidelberglaan 25, NL-3584 CS Utrecht, Netherlands
[11] Univ Med Ctr Utrecht, Div Canc & Imaging, Utrecht, Netherlands