Pre-irradiation chemotherapy in high risk medulloblastoma.

Rationale: The present study evaluates the effect of pre-irradiation chemotherapy in pediatric patients with high risk medulloblastoma. Twenty-four (24) pediatric patients attended the pediatric unit of Kasr-El-Aini Center of Radiation Oncology and Nuclear Medicine (NEMROCK) from January 2000 to January 2003.

Patients And Methods: Our patients were 13 boys and 11 girls aged 3-12 years with a median of 6.5 years. According to Chang staging system 6 cases had T2, 14 cases had T3 A and 4 cases had T3 B, 20 cases were M0, 3 cases were M1 and 1 case was M2. All patients were treated by initial surgery, 2 cycles of pre-irradiation chemotherapy followed by craniospinal radiation then by 4 cycles of post-radiation chemotherapy.

Results: Fifteen out of the 20 patients with M0 had objective response (10CR + 5PR) and no one had disease progression after pre-irradiation chemotherapy. Among 4 patients with M0 disease, 2 patients had PR and 2 had S.D. There was no disease progression among patients who received pre-irradiation chemotherapy. The 3-year overall survival and 3-year progression-free survival; (PFS) were 50% and 51%, respectively, Myelosuppression was the main toxic effect observed during pre-irradiation chemotherapy; however, there was no delay or interruption of craniospinal irradiation.

Conclusion: Pre-irradiation chemotherapy is effective in high risk medulloblastoma and is associated with acceptable side effects. The delay in craniospinal irradiation (CSI) for about 5 weeks to receive 2 courses of chemotherapy will not significantly increase disease progression. Multiple cycles of post-irradiation chemotherapy can be given safely after CSI. A larger number of patients and longer follow-up is needed to confirm the results.