Management of pilocytic astrocytoma.

Pilocytic astrocytoma, when totally resected, has a favorable outcome compared to other astrocytomas. However, when residual tumor remains, the prognosis is less satisfactory. Our study addressed the issues of prognosis in cases of residual tumor and the effect of post-surgical radiation therapy on tumor recurrence. We analyzed 41 cases of pilocytic astrocytoma which were diagnosed by histologic examination. Twenty-six patients were 15 years old or younger, and 15 patients were 16 years old or older. An analysis of the relationship between age and tumor location revealed a cerebellar predominance in both age groups; however, there were more brain stem and basal ganglia tumors among adults. Overall prognosis was favorable, with a 2-year survival rate of 97.6%, 94.6% at 5 years, and 94.6% at 10 years. Children had a better prognosis than adults due to more favorable tumor location. Gross total resection resulted in the best prognosis, i.e., no recurrence during a 10-year follow-up period. Radiation treatment after surgery suppressed residual tumor. We concluded that the best treatment for pilocytic astrocytoma is: 1) total resection, if possible, followed by 2) irradiation of any residual tumor to suppress recurrence.