Current treatment for medulloblastoma, which includes postoperative radiotherapy and 1 year of chemotherapy, does not cure many children with high-risk disease. We aimed to investigate the effectiveness of risk-adapted radiotherapy followed by a shortened period of dose-intense chemotherapy in children with medulloblastoma.

After resection, patients were classified as having average-risk medulloblastoma (≤1·5 cm² residual tumour and no metastatic disease) or high-risk medulloblastoma (>1·5 cm² residual disease or metastatic disease localised to neuraxis) medulloblastoma. All patients received risk-adapted craniospinal radiotherapy (23·4 Gy for average-risk disease and 36·0–39·6 Gy for high-risk disease) followed by four cycles of cyclophosphamide-based, dose-intensive chemotherapy. Patients were assessed regularly for disease status and treatment side-effects. The primary endpoint was 5-year event-free survival; we also measured overall survival. This study is registered with ClinicalTrials.gov, number NCT00003211.

Of 134 children with medulloblastoma who underwent treatment (86 average-risk, 48 high-risk), 119 (89%) completed the planned protocol. No treatment-related deaths occurred. 5-year overall survival was 85% (95% CI 75–94) in patients in the average-risk group and 70% (54–84) in those in the high-risk group (p=0·04); 5-year event-free survival was 83% (73–93) and 70% (55–85), respectively (p=0·046). For the 116 patients whose histology was reviewed centrally, histological subtype correlated with 5-year event-free survival (p=0·04): 84% (74–95) for classic histology, 77% (49–100) for desmoplastic tumours, and 57% (33–80) for large-cell anaplastic tumours.

Risk-adapted radiotherapy followed by a shortened schedule of dose-intensive chemotherapy can be used to improve the outcome of patients with high-risk medulloblastoma.