[1] Univ Hosp Gasthuisberg, Dept Neurosurg, B-3000 Louvain, Belgium
[2] Univ Hosp Gasthuisberg, Expt Immunol Lab, B-3000 Louvain, Belgium
[3] Catholic Univ Louvain, Dept Psychol, B-3000 Louvain, Belgium
[4] Univ Childrens Hosp, Dept Paediat Oncol Haematol & Immunol, Halle, Germany
[5] Univ Med Ctr Hamburg Eppendorf, Dept Paediat Haematol & Oncol, Hamburg, Germany
[6] Univ Texas MD Anderson Canc Ctr, Dept Paediat Oncol, Houston, TX 77030 USA
[7] Univ Hosp Gasthuisberg, Dept Paediat, B-3000 Louvain, Belgium