Abstract

Radiation therapy (RT) plays an important role in multidisciplinary therapy combined with surgery and chemotherapy for pediatric cancer. First, I will make a presentation about main indication of radiation therapy for leukemia, lymphoma, brain tumor, and extracranial tumor. For leukemia, prophylactic cranial irradiation and cranial radiation therapy for CNS involvement and total body irradiation (TBI) followed by hematopoietic stem cell transplantation will be indicated. For malignant lymphoma, involved site radiation therapy (ISRT) and TBI will be indicated. For brain tumor, many cases receive radiation therapy, for example, local radiation therapy for anaplastic astrocytoma, cranio-spinal irradiation for medulloblastoma, or whole ventricle irradiation for intracranial germinoma. For extracranial tumor, loco-regional radiation therapy will be indicated for high risk neuroblastoma, Wilms tumor, and rabdomyosarcoma. Second, I will make a presentation about character of radiation therapy for pediatric cancer. Large radiation field are applied, for example, TBI for leukemia/lymphoma, cranio-spinal irradiation for medulloblastoma, whole abdominal irradiation for Wilms tumor, whole lung irradiation for Wilms tumor and Ewing sarcoma family tumor. Second character is low radiation dose because chemotherapy is effective, so reduced radiation dose is applied with combination with chemotherapy. However, late complications, especially second cancers, is important issue, so fraction size should be lower as possible, and proton beam therapy is expected to reduce radiation induced late complications, especially second cancers.