[1] Sophia Childrens Univ Hosp, Erasmus MC, Rotterdam, Netherlands
[2] Hop Robert Debre, F-75019 Paris, France
[3] Charles Univ Prague, Sch Med 2, Prague, Czech Republic
[4] Hannover Med Sch, Hannover, Germany
[5] Dutch Childhood Oncol Grp, The Hague, Netherlands
[6] Royal Hosp Sick Children, Glasgow G3 8SJ, Lanark, Scotland
[7] Princess Maxima Ctr Pediat Oncol, Utrecht, Netherlands
[8] Erasmus MC, Rotterdam, Netherlands