Adjuvant chemotherapy after reduced craniospinal irradiation dose in children with average-risk medulloblastoma: a 5-year follow-up study

This study was undertaken to determine the effect of adjuvant chemotherapy combined with reduced-dose craniospinal irradiation (CSI) on survival and neurocognitive sequelae of radiotherapy (RT) in patients with average- risk medulloblastoma above the age of 3 years. Thirty-three children between 3 and 10 years of age with average-risk medulloblastoma were treated with postoperative reduced-dose CSI (24.0 Gy) and 30.6 Gy of local RT (total of 54.6 Gy) and then with adjuvant chemotherapy consisting of cisplatin, vincristine, and cyclophosphamide every 4 weeks for 8 cycles. At 5 years, event-free survival (EFS) was 79%, while overall survival (OS) was 85%. Sites of relapse were local in 3%, neuraxis in 9% and both local and neuraxis in 9% of the patients. Chemotherapy was well tolerated. Hematopoietic toxicity was the most predominant side effect followed by vomiting and ototoxicity. No grade III or IV nephrotoxicity or neurotoxicity and no treatment-related deaths were encountered. Insignificant decline of intelligence quotient (IQ) was reported in 28.6% of the patients. The preliminary results of adjuvant chemotherapy after reduced-dose CSI in average-risk medulloblastoma patients are encouraging and effective, and can be applied safely with acceptable toxicity.