[1] Alder Hey Childrens NHS Fdn Trust, Dept Paediat Haematol & Oncol, Liverpool, Merseyside, England
[2] Great North Childrens Hosp, Dept Paediat Haematol & Oncol, Newcastle Upon Tyne, Tyne & Wear, England
[3] Cambridge Univ Hosp NHS Fdn Trust, Dept Paediat Haematol & Oncol, Cambridge CB2 0QQ, England
[4] SickKids, Paediat Brain Tumour Program, Dept Paediat Haematol & Oncol, Toronto, ON, Canada
[5] Cambridge Univ Hosp NHS Fdn Trust, Dept Radiat Oncol, Cambridge, England
[6] Cambridge Univ Hosp NHS Fdn Trust, Dept Paediat Neuroophthalmol, Cambridge, England
[7] Royal Manchester Childrens Hosp, CBTRN, Manchester, Lancs, England
[8] Univ Manchester, Fac Biol Med & Hlth, Manchester, Lancs, England
[9] Univ Hosp Bonn, Dept Paediat Haematol & Oncol, Bonn, Germany
[10] Cambridge Univ Hosp NHS Fdn Trust, Paediat Oncol, Cambridge, England