Major advances in pediatric oncology have been made since surgery, radiation therapy, and chemotherapy have been integrated in the management of children with cancer. Combined chemo-radiotherapy can be used successfully to control minimal residual disease after resections. However, particularly with certain drugs, radiation reactions can be augmented severely so as to produce crippling if not lethal damage. The skill and expertise of an experienced team is needed if the benefits of combined care are to be maximized, and the risks minimized.