- must be enrolled in a national or European protocol for treatment of Wilms Tumours, Neuroblastoma, Soft tissue sarcoma, Ewing Sarcoma or Acute lymphoblastic leukaemia and must be treated with doxorubicin according to that protocol Or Patients < 3 years enrolled or listed in any national or European study protocol for any paediatric malignancy. Treatment with doxorubicin has to be according to that protocol.