Chemotherapy: vincristine 0.05 mg/kg (or 1.5 mg/m2 for children ≥ 3 years of age) on Day 1, carboplatin 18.6 mg/kg (or 560 mg/m2 for children ≥ 3 years of age) on Day 1, etoposide 5.0 mg/kg/day (or 150 mg/ m2 for children ≥ 3 years of age) on Days 1 and 2 and 2. Cycles were repeated every 21 days for six cycles.

quality of life (PedsQL4.0 scale) before each treatment, at 1,3,6,9,12,18,24,30,36,42,48,54,60 months after the treatment. PedsQL 4.0 questionnaire has two modules (reported by parents and children) with 23 items encompassing the physical domains (8 items), emotional (5 items), social (5 items) and school (5 items). A five scores scale is used, after being asked, ''How much, in the last month, your child has had problems with'' (0 = never a problem; 1 = almost never a problem; 2 = sometimes a problem; 3 = is often a problem and 4 = almost always a problem). The items are reverse-score and linearly transformed to a scale from 0 to 100 (0=100, 1=75, 2=50, 3=25, 4 = 0). So high scores indicate better QoL.

All costs, including direct cost and indirect cost, are expressed in Chinese YUAN. Direct costs include the average cost of systemic chemotherapy, operation, supportive treatment, and examination. Indirect costs include accommodation, transportation, diet, and lost income of parents.