PEDT-06 THERAPEUTIC STRATEGY FOR DISSEMINATED PILOCYTIC ASTROCYTOMAS

BACKGROUND: Pilocytic astrocytoma is one of the common tumors found during childhood. However, the clinical course of disseminated pilocytic astrocytoma is not clearly known. Here, we present two cases with disseminated pilocytic astrocytoma and discuss the treatment strategy. Patients We treated a 7-year-old female (case 1) and 9-year-old male (case 2) with hypothalamic pilocytic astrocytomas. The results of magnetic resonance imaging showed diffuse spinal dissemination at diagnosis. Chemotherapy with vincristine and carboplatin was administered as the firstline therapy. The tumors showed some shrinkage, and symptoms improved. During chemotherapy, the patients developed allergies to carboplatin. Therefore, we changed the chemotherapy treatment to vincristine. Other adverse events were not observed. In Case 1, we observed an intratumoral hemorrhage and hydrocephalus due to occlusion of the foramen Monro. Endoscopic surgery was performed, and no clinical deficit was observed. Case 2 underwent ventricular peritoneal shunt procedure for communicating hydrocephalus and a reoperation for shunt malfunction because of dense cerebrospinal fluid with elevated protein levels. The patients have not undergone radiotherapy until now. They had no severe clinical symptoms and went to school for 5 and 10 years, respectively, after the diagnoses. CONCLUSION: Chemotherapy for disseminated pilocytic astrocytoma is effective and may help in avoiding radiotherapy. Chemotherapy should be administered before radiotherapy, considering long-term complications.