Long-Term Results of Combined Surgery and Radiotherapy of Pilocytic Astrocytomas in the Middle Cranial Fossa

The incidence of pilocytic astrocytomas (WHO astrocytoma grade I) among brain tumors amounts to 6.5% [1, 2, 11]. In children this type of tumor is the most frequent orbital neoplasm [10, 12]. Radical extirpation is not possible because of extension into the optic system and infiltration of the neighboring brain substance, especially the hypothalamus. According to the literature, 25% of optic gliomas involve one optic nerve, 50% are located in the optic chiasm, and in 25% of cases there is infiltration of the hypothalamus [4, 6]. Where subtotal extirpation has been carried out, postoperative radiotherapy can prevent tumor progression [1, 5, 9].