[1] Karolinska Inst, Dept Womens & Childrens Hlth, Childhood Canc Res Unit, Tomtebodavagen 18A, S-17177 Stockholm, Sweden
[2] Karolinska Univ Hosp, Dept Pediat Oncol, Stockholm, Sweden
[3] Marie Cederschiold Univ, Palliat Res Ctr, Dept Hlth Care Sci, Stockholm, Sweden
[4] UCL, Great Ormond St Inst Child Hlth, Louis Dundas Ctr Childrens Palliat Care, London, England
[5] Aarhus Univ Hosp, Dept Pediat & Adolescent Med, Aarhus, Denmark
[6] Aarhus Univ, Fac Hlth, Dept Clin Med, Aarhus, Denmark
[7] Univ Turku, Turku Univ Hosp, Turku, Finland
[8] FICAN West, Turku, Finland
[9] Karolinska Inst, Swedish Childhood Canc Registry, Stockholm, Sweden
[10] Uppsala Univ, Dept Womens & Childrens Hlth, Uppsala, Sweden
[11] Uppsala Univ Hosp, Pediat Oncol, Uppsala, Sweden