HG-107: RADIATION-INDUCED GLIOBLASTOMA MULTOFORME FOLLOWING THE TREATMENT FOR ALL AND MEDULLOBLASTOMA IN CHILDREN

There are limited reports of a secondary glioblastoma in survivors of childhood cancer. There were 4 boys and 4 girls in our group who previously had received radiation and chemotherapy for either acute lymphoblastic leukaemia (n = 6) or medulloblastoma (n = 2). Children developed glioblastoma 3–10 years thereafter (median 5 yrs). A median of a dose of a primary cranial irradiation was 18 Gy. A tumor was localized supratentorialy in 7 cases and was in cerebellum in one patient. Patients underwent a surgery resection (2 – total, 4 – subtotal, 2- partial) followed by a standard fractionated local radiation and chemotherapy. The dose of irradiation was 55-60 Gy (median 55 Gy). Two patients progressed after subtotal/partial resection and irradiation (2 - 3 mo after surgery). Five children received temozolomide (TMZ) as a single-agent 150-200 mg/m² administered on 5 consecutive days every 28 days (number of courses 2 - 8, median 3). One patient underwent only surgery and steroids as a palliative care. In 3 cases the chemotherapy was stopped because severe myelotoxicity after 2-4 courses. All patients have died or lost during 24 months of the follow up; the median of overall survival time was 9 months. Overall survival rate was 37,5± 17,1 % at 1 year after diagnosis with follow up 4 -24 months. The prognosis in secondary malignant gliomas in children is poor despite the therapy. The risk of a severe myelotoxicity is high. ALL and medulloblastoma survivors must undergo systematic, long-term surveillance for early detection of intracranial neoplasms.