Cerebral radiation necrosis (CRN) is a well-documented late complication of radiation therapy for cancers, and may have a devastating effect on the patient's quality of life (QOL). However,CRN was once regarded as a progressive and irreversible disease, no standard therapy has been suggested for CRN. In our clinical practice, we have used monosialotetrahexosylganglioside (GM1)to treat CRN, and found that GM1 can successfully reverse CRN. So we carried out this prospective study to test the efficacy of GM1 for CRN.