Long-term results of combined preradiation chemotherapy and age-tailored radiotherapy doses for childhood medulloblastoma.

ABSTRACT

To reduce the sequelae of craniospinal irradiation (CSI) in children under 10 (≥3) years old and to improve the prognosis for high-risk medulloblastoma in adolescents, we adjusted postoperative chemotherapy and CSI doses to patients' stage and age. From 1986 to 1995, 73 patients entered the study. Children under 10 and adolescents with metastases, residual disease (RD) or stage >T3 received postoperative IV vincristine and high-dose (HD) ± intrathecal (IT) methotrexate, while standard-risk adolescents were given IV vincristine and IT methotrexate. Chemotherapy was followed by CSI (19.8 Gy for children <10; 36 Gy for adolescents), with a 54-Gy posterior fossa boost. Maintenance chemotherapy with lomustine and vincristine was administered for a year afterwards. A total of 39 children were under 10 of whom 20 had metastases. Response to chemotherapy was recorded in 70%, but 5-year EFS and OS were only 48 and 56%, respectively. Results were significantly worse for metastatic cases, patients under 10, those with RD, and those staged without MRI (unavailable early in the study). Efforts to preserve survivors' quality of life did not pay off, and most patients over 30 still depended on their parents' income and had severe cognitive/endocrine disabilities. In conclusion, despite a very high response rate with this preradiation HD methotrexate schedule, the outcome for high-risk medulloblastoma patients did not improve (especially when lower CSI doses were used) and patients still developed severe morbidities.