Neuroblastoma is a malignant tumor of the nervous system in young children. Unlike brain tumors, neuroblastomas occur in the peripheral (non-brain, non-spinal cord) nervous system, often arising in the deep abdomen or chest, though other sites are possible. Although neuroblastomas can be treated with proton therapy, the radiation doses used in this disease are relatively low, and most patients can be treated with conventional radiation techniques without high risks. However, patients with tumors adjacent to the kidney, eye, lung or heart, may benefit from proton therapy.