[1] Sophia Childrens Univ Hosp, Dept Pediat Oncol Hematol, Erasmus Med Ctr, NL-3015 GJ Rotterdam, Netherlands
[2] Leiden Univ, Med Ctr, Dept Pediat, Leiden, Netherlands
[3] UMCU Wilhelmina Childrens Hosp, Dept Pediat Hematol Oncol, Utrecht, Netherlands
[4] St Anna Childrens Hosp, Dept Pediat, A-1090 Vienna, Austria
[5] Charles Univ Prague, Univ Hosp Motol, Dept Pediat Hematol Oncol, Prague, Czech Republic
[6] Univ Freiburg, Dept Pediat, D-7800 Freiburg, Germany
[7] Univ Pavia, Fondaz IRCCS Policlin San Matteo, I-27100 Pavia, Italy