Children with high risk medulloblastoma and non-cerebellar PNET’s were treated on a phase II study of pre-radiotherapy chemotherapy (CHT) followed by high dose, hyperfractionated craniospinal radiotherapy (CSRT). The protocol objectives were to verify feasibility and monitor progression-free (PFS) and overall survival (OS).
Methods and Materials
Eligibility criteria included age >3 years at diagnosis, medulloblastoma with either high M stage and/or >1.5 cm2 post-op residual disease and all patients with non-cerebellar PNET. Treatment was initiated with 5 alternating monthly cycles of CHT [A (cisplatin, cyclophosphamide, etoposide and vincristine, B (carboplatin and etoposide), A, B and A] followed by hyperfractionated CSRT (40 Gy) with a boost to the primary tumor (72 Gy) given in twice daily 1 Gy fractions.
The valid study group consisted of 124 patients whose median age at diagnosis was 7.8 years. Eighty-four (68%) patients completed the entire protocol within the study guidelines of 9 months and the median time to complete CSRT was 1.6 months. Major reasons for failure to complete CHT included progressive disease (17%) and toxic death (2.4%). The 5-year PFS and OS were 43 ± 5% and 52 ± 5%. No significant differences were detected in subset analysis related to response to CHT, site of primary tumor, post-op residual disease or M-stage.
The feasibility of this intensive multi-modality protocol was confirmed and response to pre-RT CHT did not impact on survival. Survival data from this protocol can not be compared to other studies, given the protocol design.