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.

Inclusion Criteria:

The necrotic mass shown on MRI must be measured in two dimensions. No local or regional recurrence, no distant metastasis. Karnofsky performance status of at least 70 and were supposed to live more than 6 months.

Exclusion Criteria:

• CRN combined with local or regional relapse, or with distant metastasis. ② CRN combined with other cerebrovascular disease. ③CRN combined with the second primary malignancy. ④ CRN without neurologic symptoms or signs. ⑤ CRN combined with diabetes. ⑥CRN patients that were supposed to live less than 6 months.

Patients must have undergone definitive RT for histologically confirmed NPC years before. They were required to have at least two consecutive magnetic resonance imaging (MRI) study supporting the diagnosis of CRN with an interval of 3-4 months, with the second MRI showing progressive disease compared with the first MRI. The necrotic mass shown on MRI must be measured in two dimensions in order to define the response to treatment. Other radiologic studies were also required to support the non-existence of local or regional recurrence, distant metastasis. Patients must have undergone mental status examinations and had progressive neurologic symptoms or signs. In addition, they were required to have a Karnofsky performance status of at least 70 and were supposed to live more than 6 months.